Molecules

319 KiB

Open AccessArticle

Determination and Comparison of Seed Oil Triacylglycerol Composition of Various Soybeans (Glycine max (L.)) Using ¹H-NMR Spectroscopy

by Won Woo Kim, Ho Sik Rho, Yong Deog Hong, Myung Hun Yeom, Song Seok Shin, Jun Gon Yi, Min-Seuk Lee, Hye Yoon Park and Dong Ha Cho

Molecules 2013, 18(11), 14448-14454; https://doi.org/10.3390/molecules181114448 - 21 Nov 2013

Cited by 7 | Viewed by 6600

Abstract

Seed oil triacylglycerol (TAG) composition of 32 soybean varieties were determined and compared using ¹H-NMR. The contents of linolenic (Ln), linoleic (L), and oleic (O) ranged from 10.7% to 19.3%, 37.4%–50.1%, and 15.7%–34.1%, respectively. As is evident, linoleic acid was the major [...] Read more.

Seed oil triacylglycerol (TAG) composition of 32 soybean varieties were determined and compared using ¹H-NMR. The contents of linolenic (Ln), linoleic (L), and oleic (O) ranged from 10.7% to 19.3%, 37.4%–50.1%, and 15.7%–34.1%, respectively. As is evident, linoleic acid was the major fatty acid of soybean oil. Compositional differences among the varieties were observed. Natural oils containing unsaturated groups have been regarded as important nutrient and cosmetic ingredients because of their various biological activities. The TAG profiles of the soy bean oils could be useful for distinguishing the origin of seeds and controlling the quality of soybean oils. To the best of our knowledge, this is the first study in which the TAG composition of various soybean oils has been analyzed using the ¹H-NMR method. Full article

(This article belongs to the Section Natural Products Chemistry)

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1560 KiB

Open AccessArticle

Deracemization of Axially Chiral Nicotinamides by Dynamic Salt Formation with Enantiopure Dibenzoyltartaric Acid (DBTA)

by Fumitoshi Yagishita, Norifumi Kamataki, Kazuma Okamoto, Shota Kanno, Takashi Mino, Hyuma Masu and Masami Sakamoto

Molecules 2013, 18(11), 14430-14447; https://doi.org/10.3390/molecules181114430 - 21 Nov 2013

Cited by 7 | Viewed by 7479

Abstract

Dynamic atroposelective resolution of chiral salts derived from oily racemic nicotinamides and enantiopure dibenzoyltartaric acid (DBTA) was achieved by crystallization. The absolute structures of the axial chiral nicotinamides were determined by X-ray structural analysis. The chirality could be controlled by the selection of [...] Read more.

Dynamic atroposelective resolution of chiral salts derived from oily racemic nicotinamides and enantiopure dibenzoyltartaric acid (DBTA) was achieved by crystallization. The absolute structures of the axial chiral nicotinamides were determined by X-ray structural analysis. The chirality could be controlled by the selection of enantiopure DBTA as a chiral auxiliary. The axial chirality generated by dynamic salt formation was retained for a long period after dissolving the chiral salt in solution even after removal of the chiral acid. The rate of racemization of nicotinamides could be controlled based on the temperature and solvent properties, and that of the salts was prolonged compared to free nicotinamides, as the molecular structure of the pyridinium ion in the salts was different from that of acid-free nicotinamides. Full article

(This article belongs to the Special Issue Dynamic Stereochemistry)

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3029 KiB

Open AccessArticle

Solution Structure of the Circular γ-Domain Analog from the Wheat Metallothionein E_c-1

by Katsiaryna Tarasava, Silke Johannsen and Eva Freisinger

Molecules 2013, 18(11), 14414-14429; https://doi.org/10.3390/molecules181114414 - 21 Nov 2013

Cited by 8 | Viewed by 6026

Abstract

The first cyclic analog of a metallothionein (MT) was prepared and analyzed by UV and (magnetic) circular dichroism spectroscopy, ESI-MS as well as NMR spectroscopy. Results reveal that the evaluated cyclic g-E_c-1 domain of the wheat MT E_c-1 retains [...] Read more.

The first cyclic analog of a metallothionein (MT) was prepared and analyzed by UV and (magnetic) circular dichroism spectroscopy, ESI-MS as well as NMR spectroscopy. Results reveal that the evaluated cyclic g-E_c-1 domain of the wheat MT E_c-1 retains its ability to coordinate two Zn(II) or Cd(II) ions and adopts a three-dimensional structure that is highly similar to the one of the linear wild-type form. However, the reduced flexibility of the protein backbone facilitates structure solution significantly and results in a certain stabilization of metal binding to the protein. Full article

(This article belongs to the Special Issue NMR of Proteins and Small Biomolecules)

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2782 KiB

Open AccessArticle

Biological Activity of Propolis-Honey Balm in the Treatment of Experimentally-Evoked Burn Wounds

by Żaneta Jastrzębska-Stojko, Rafał Stojko, Anna Rzepecka-Stojko, Agata Kabała-Dzik and Jerzy Stojko

Molecules 2013, 18(11), 14397-14413; https://doi.org/10.3390/molecules181114397 - 21 Nov 2013

Cited by 34 | Viewed by 8237

Abstract

Medicines of biogenic origin with micro-organic, regenerative and analgesic properties are becoming more and more significant in the treatment of burn wounds. These properties are found in apitherapeutics such as propolis and honey—products collected and processed by a honey bee. Their effect on [...] Read more.

Medicines of biogenic origin with micro-organic, regenerative and analgesic properties are becoming more and more significant in the treatment of burn wounds. These properties are found in apitherapeutics such as propolis and honey—products collected and processed by a honey bee. Their effect on the course of the healing processes is multidirectional. The aim of the study was a histopathological and biochemical analysis of the processes of scar formation in experimentally evoked burn wounds in white pigs treated with the 1% and 3% Sepropol balms containing standardized extracts of propolis and honey. The results were compared with the therapeutic effects obtained with dermazin cream (1% silver sulfadiazine). The level of collagen was determined in the wounds treated with 1% and 3% Sepropol and compared with the collagen level in healthy skin and wounds treated with dermazin. Granulation and regenerated epithelium formation times were compared, with the 3% Sepropol being by far the most effective. The 3% Sepropol also increased the collagen level to 116% with the control sub-groups scoring between 80% and 98%. The results show the healing process of burn wounds in pigs treated with the Sepropol balm starts earlier and has a faster course than the standard dermazin therapy. Full article

(This article belongs to the Section Natural Products Chemistry)

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517 KiB

Open AccessArticle

An In Vitro Study of the Antimicrobial Effects of Indigo Naturalis Prepared from Strobilanthes formosanus Moore

by Yin-Ru Chiang, Ann Li, Yann-Lii Leu, Jia-You Fang and Yin-Ku Lin

Molecules 2013, 18(11), 14381-14396; https://doi.org/10.3390/molecules181114381 - 21 Nov 2013

Cited by 43 | Viewed by 7394

Abstract

Indigo naturalis is effective in treating nail psoriasis coexisting with microorganism infections. This study examines the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore. Eight bacterial and seven fungal strains were assayed using the agar diffusion method to examine the effects [...] Read more.

Indigo naturalis is effective in treating nail psoriasis coexisting with microorganism infections. This study examines the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore. Eight bacterial and seven fungal strains were assayed using the agar diffusion method to examine the effects of indigo naturalis and its bioactive compounds. The bioactive compounds of indigo naturalis were purified sequentially using GFC, TLC, and HPLC. Their structures were identified using mass spectrometry and NMR spectroscopy. UPLC-MS/MS was applied to compare the metabolome profiles of indigo naturalis ethyl-acetate (EA) extract and its source plant, Strobilanthes formosanus Moore. The results of in vitro antimicrobial assays showed that indigo naturalis EA-extract significantly (≥1 mg/disc) inhibits Gram-positive bacteria (Staphylococcus aureus, S. epidermis and methicillin-resistant S. aureus (MRSA)) and mildly inhibits non-dermatophytic onychomycosis pathogens (Aspergillus fumigates and Candida albicans), but has little effect on dermatophyes. Isatin and tryptanthrin were identified as the bioactive compounds of indigo naturalis using S. aureus and S. epidermis as the bioassay model. Both bioactive ingredients had no effect on all tested fungi. In summary, indigo naturalis prepared from Strobilanthes formosanus Moore exhibits antimicrobial effects on Staphylococcus and non-dermatophytic onychomycosis pathogens. Tryptanthrin and isatin may be its major bioactive ingredients against Staphylococcus and the inhibitory effect on MRSA may be due to other unidentified ingredients. Full article

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371 KiB

Open AccessArticle

Optimization of Extraction of Novel Pectinase Enzyme Discovered in Red Pitaya (Hylocereus polyrhizus) Peel

by Nor Khanani Zohdi and Mehrnoush Amid

Molecules 2013, 18(11), 14366-14380; https://doi.org/10.3390/molecules181114366 - 20 Nov 2013

Cited by 27 | Viewed by 7012

Abstract

Plant peels could be a potential source of novel pectinases for use in various industrial applications due to their broad substrate specificity with high stability under extreme conditions. Therefore, the extraction conditions of a novel pectinase enzyme from pitaya peel was optimized in [...] Read more.

Plant peels could be a potential source of novel pectinases for use in various industrial applications due to their broad substrate specificity with high stability under extreme conditions. Therefore, the extraction conditions of a novel pectinase enzyme from pitaya peel was optimized in this study. The effect of extraction variables, namely buffer to sample ratio (2:1 to 8:1, X₁), extraction temperature (−15 to +25 °C, X₂) and buffer pH (4.0 to 12.0, X₃) on specific activity, temperature stability, storage stability and surfactant agent stability of pectinase from pitaya peel was investigated. The study demonstrated that the optimum conditions for the extraction of pectinase from pitaya sources could improve the enzymatic characteristics of the enzyme and protect its activity and stability during the extraction procedure. The optimum extraction conditions cause the pectinase to achieve high specific activity (15.31 U/mg), temperature stability (78%), storage stability (88%) and surfactant agent stability (83%). The most desirable conditions to achieve the highest activity and stability of pectinase enzyme from pitaya peel were the use of 5:1 buffer to sample ratio at 5 °C and pH 8.0. Full article

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648 KiB

Open AccessArticle

Modulation of the Microenvironment Surrounding the Active Site of Penicillin G Acylase Immobilized on Acrylic Carriers Improves the Enzymatic Synthesis of Cephalosporins

by Paolo Bonomi, Teodora Bavaro, Immacolata Serra, Auro Tagliani, Marco Terreni and Daniela Ubiali

Molecules 2013, 18(11), 14349-14365; https://doi.org/10.3390/molecules181114349 - 20 Nov 2013

Cited by 36 | Viewed by 6703

Abstract

The catalytic properties of penicillin G acylase (PGA) from Escherichia coli in kinetically controlled synthesis of β-lactam antibiotics are negatively affected upon immobilization on hydrophobic acrylic carriers. Two strategies have been here pursued to improve the synthetic performance of PGA immobilized on epoxy-activated [...] Read more.

The catalytic properties of penicillin G acylase (PGA) from Escherichia coli in kinetically controlled synthesis of β-lactam antibiotics are negatively affected upon immobilization on hydrophobic acrylic carriers. Two strategies have been here pursued to improve the synthetic performance of PGA immobilized on epoxy-activated acrylic carriers. First, an aldehyde-based spacer was inserted on the carrier surface by glutaraldehyde activation (immobilization yield = 50%). The resulting 3-fold higher synthesis/hydrolysis ratio (vs/vh₁ = 9.7 ± 0.7 and 10.9 ± 0.7 for Eupergit^® C and Sepabeads^® EC-EP, respectively) with respect to the unmodified support (vs/vh₁ = 3.3 ± 0.4) was ascribed to a facilitated diffusion of substrates and products as a result of the increased distance between the enzyme and the carrier surface. A second series of catalysts was prepared by direct immobilization of PGA on epoxy-activated acrylic carriers (Eupergit^® C), followed by quenching of oxiranes not involved in the binding with the protein with different nucleophiles (amino acids, amines, amino alcohols, thiols and amino thiols). In most cases, this derivatization increased the synthesis/hydrolysis ratio with respect to the non derivatized carrier. Particularly, post-immobilization treatment with cysteine resulted in about 2.5-fold higher vs/vh₁ compared to the untreated biocatalyst, although the immobilization yield decreased from 70% (untreated Eupergit^® C) to 20%. Glutaraldehyde- and cysteine-treated Eupergit^® C catalyzed the synthesis of cefazolin in 88% (±0.9) and 87% (±1.6) conversion, respectively, whereas untreated Eupergit^® C afforded this antibiotic in 79% (±1.2) conversion. Full article

(This article belongs to the Special Issue Enzyme Chemistry)

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1071 KiB

Open AccessCommunication

Antibacterial Activity of Glucomoringin Bioactivated with Myrosinase against Two Important Pathogens Affecting the Health of Long-Term Patients in Hospitals

by Maria Galuppo, Gina Rosalinda De Nicola, Renato Iori, Pia Dell'Utri, Placido Bramanti and Emanuela Mazzon

Molecules 2013, 18(11), 14340-14348; https://doi.org/10.3390/molecules181114340 - 20 Nov 2013

Cited by 69 | Viewed by 9712

Abstract

Glucosinolates (GLs) are natural compounds present in species of the order Brassicales and precursors of bioactive isothiocyanates (ITCs). In the recent years, they have been studied mainly for their chemopreventive as well as novel chemotherapeutics properties. Among them 4-(α-L-rhamnosyloxy)benzyl glucosinolate (glucomoringin; GMG), purified [...] Read more.

Glucosinolates (GLs) are natural compounds present in species of the order Brassicales and precursors of bioactive isothiocyanates (ITCs). In the recent years, they have been studied mainly for their chemopreventive as well as novel chemotherapeutics properties. Among them 4-(α-L-rhamnosyloxy)benzyl glucosinolate (glucomoringin; GMG), purified from seeds of Moringa oleifera Lam., a plant belonging to the Moringaceae family, represents an uncommon member of the GL family with peculiar characteristics. This short communication reports new evidences about the properties of GMG and presents a new innovative utilization of the molecule. The bioactivation of GMG by myrosinase enzyme just before treatment, permits to maximize the power of the final product of the reaction, which is the 4-(α-L-rhamnosyloxy)benzyl isothiocyanate (GMG-ITC). We tested the antibiotic activity of this latter compound on two strains of pathogens affecting the health of patients in hospital, namely Staphylococcus aureus and Enterococcus casseliflavus, and on the yeast Candida albicans. Results show that the sensibility of S. aureus BAA-977 strain and E. casseliflavus to GMG-ITC treatment reveals an important possible application of this molecule in the clinical care of patients, more and more often resistant to traditional therapies. Full article

(This article belongs to the Section Natural Products Chemistry)

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619 KiB

Open AccessArticle

Tuning a 96-Well Microtiter Plate Fluorescence-Based Assay to Identify AGE Inhibitors in Crude Plant Extracts

by Luc Séro, Lionel Sanguinet, Patricia Blanchard, Bach Tai Dang, Sylvie Morel, Pascal Richomme, Denis Séraphin and Séverine Derbré

Molecules 2013, 18(11), 14320-14339; https://doi.org/10.3390/molecules181114320 - 19 Nov 2013

Cited by 95 | Viewed by 13662

Abstract

Advanced glycation end-products (AGEs) are involved in the pathogenesis of numerous diseases. Among them, cellular accumulation of AGEs contributes to vascular complications in diabetes. Besides using drugs to lower blood sugar, a balanced diet and the intake of herbal products potentially limiting AGE [...] Read more.

Advanced glycation end-products (AGEs) are involved in the pathogenesis of numerous diseases. Among them, cellular accumulation of AGEs contributes to vascular complications in diabetes. Besides using drugs to lower blood sugar, a balanced diet and the intake of herbal products potentially limiting AGE formation could be considered beneficial for patients’ health. The current paper presents a simple and cheap high-throughput screening (HTS) assay based on AGE fluorescence and suitable for plant extract screening. We have already implemented an HTS assay based on vesperlysines-like fluorescing AGEs quickly (24 h) formed from BSA and ribose under physiological conditions. However, interference was noted when fluorescent compounds and/or complex mixtures were tested. To overcome these problems and apply this HTS assay to plant extracts, we developed a technique for systematic quantification of both vesperlysines (λ_exc 370 nm; λ_em 440 nm) and pentosidine-like (λ_exc 335 nm; λ_em 385 nm) AGEs. In a batch of medicinal and food plant extracts, hits were selected as soon as fluorescence decreased under a fixed threshold for at least one wavelength. Hits revealed during this study appeared to contain well-known and powerful anti-AGE substances, thus demonstrating the suitability of this assay for screening crude extracts (0.1 mg/mL). Finally, quercetin was found to be a more powerful reference compound than aminoguanidine in such assay. Full article

(This article belongs to the Section Natural Products Chemistry)

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301 KiB

Open AccessArticle

Synthesis of Quaternary Heterocyclic Salts

by Angela J. Winstead, Grace Nyambura, Rachael Matthews, Deveine Toney and Stanley Oyaghire

Molecules 2013, 18(11), 14306-14319; https://doi.org/10.3390/molecules181114306 - 19 Nov 2013

Cited by 21 | Viewed by 8434

Abstract

The microwave synthesis of twenty quaternary ammonium salts is described. The syntheses feature comparable yields to conventional synthetic methods reported in the current literature with reduced reaction times and the absence of solvent or minimal solvent. Full article

(This article belongs to the Section Organic Chemistry)

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376 KiB

Open AccessCommunication

The Formation of 2,2,4-Trimethyl-2,3-dihydro-1H-1,5-Benzodiazepine from 1,2-Diaminobenzene in the Presence of Acetone

by Felix Odame, Phumelele Kleyi, Eric Hosten, Richard Betz, Kevin Lobb and Zenixole Tshentu

Molecules 2013, 18(11), 14293-14305; https://doi.org/10.3390/molecules181114293 - 19 Nov 2013

Cited by 10 | Viewed by 9152

Abstract

In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of [...] Read more.

In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of two moles of acetone with the amine groups resulted in the formation of the benzodiazepine which crystallized as an iminium cation forming a salt with the isophthalate anion. The formation of benzodiazepine was also confirmed by performing the reaction of o-phenylenediamine with excess acetone in ethanol under conventional heating conditions. The compounds were characterized by NMR, FTIR, HRMS and microanalysis as well as X-ray crystallography. The reaction mechanism leading to the formation of benzodiazepine is also discussed. Full article

(This article belongs to the Section Organic Chemistry)

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212 KiB

Open AccessArticle

Triterpenoids and Steroids from Ganoderma mastoporum and Their Inhibitory Effects on Superoxide Anion Generation and Elastase Release

by Tran Dinh Thang, Ping-Chung Kuo, Tsong-Long Hwang, Mei-Lin Yang, Nguyen Thi Bich Ngoc, Tran Thi Ngoc Han, Chi-Wen Lin and Tian-Shung Wu

Molecules 2013, 18(11), 14285-14292; https://doi.org/10.3390/molecules181114285 - 19 Nov 2013

Cited by 12 | Viewed by 5762

Abstract

The methanol extracts of the fruiting bodies of Ganoderma mastoporum collected in Vietnam was purified to afford eight compounds, including three triterpenoids and five steroids. The purified compounds were examined for their inhibitory effects against superoxide anion generation and elastase release. Among the [...] Read more.

The methanol extracts of the fruiting bodies of Ganoderma mastoporum collected in Vietnam was purified to afford eight compounds, including three triterpenoids and five steroids. The purified compounds were examined for their inhibitory effects against superoxide anion generation and elastase release. Among the tested compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) exhibited the most significant inhibition towards superoxide anion generation and elastase release with IC₅₀ values of 2.30 ± 0.38 and 1.94 ± 0.50 µg/mL, respectively. Full article

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680 KiB

Open AccessReview

Synthesis of DNA/RNA and Their Analogs via Phosphoramidite and H-Phosphonate Chemistries

by Subhadeep Roy and Marvin Caruthers

Molecules 2013, 18(11), 14268-14284; https://doi.org/10.3390/molecules181114268 - 18 Nov 2013

Cited by 91 | Viewed by 17996

Abstract

The chemical synthesis of DNA and RNA is universally carried out using nucleoside phosphoramidites or H-phosphonates as synthons. This review focuses on the phosphorus chemistry behind these synthons and how it has been developed to generate procedures whereby yields per condensation approach 100% [...] Read more.

The chemical synthesis of DNA and RNA is universally carried out using nucleoside phosphoramidites or H-phosphonates as synthons. This review focuses on the phosphorus chemistry behind these synthons and how it has been developed to generate procedures whereby yields per condensation approach 100% with very few side products. Additionally the synthesis and properties of certain DNA and RNA analogs that are modified at phosphorus will also be discussed. These analogs include boranephosphonates, metallophosphonates, and alkylboranephosphines. Full article

(This article belongs to the Special Issue Organophosphorus Chemistry)

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1299 KiB

Open AccessArticle

Gold Nanoparticles on Mesoporous SiO₂-Coated Magnetic Fe₃O₄ Spheres: A Magnetically Separatable Catalyst with Good Thermal Stability

by Huan Liu, Chao Lin, Zhen Ma, Hongbo Yu and Shenghu Zhou

Molecules 2013, 18(11), 14258-14267; https://doi.org/10.3390/molecules181114258 - 18 Nov 2013

Cited by 13 | Viewed by 8055

Abstract

Fe₃O₄ spheres with an average size of 273 nm were prepared in the presence of CTAB by a solvothermal method. The spheres were modified by a thin layer of SiO₂, and then coated by mesoporous SiO₂ (m-SiO [...] Read more.

Fe₃O₄ spheres with an average size of 273 nm were prepared in the presence of CTAB by a solvothermal method. The spheres were modified by a thin layer of SiO₂, and then coated by mesoporous SiO₂ (m-SiO₂) films, by using TEOS as a precursor and CTAB as a soft template. The resulting m-SiO₂/Fe₃O₄ spheres, with an average particle size of 320 nm, a high surface area (656 m²/g), and ordered nanopores (average pore size 2.5 nm), were loaded with gold nanoparticles (average size 3.3 nm). The presence of m-SiO₂ coating could stabilize gold nanoparticles against sintering at 500 °C. The material showed better performance than a conventional Au/SiO₂ catalyst in catalytic reduction of p-nitrophenol with NaBH₄. It can be separated from the reaction mixture by a magnet and be recycled without obvious loss of catalytic activity. Relevant characterization by XRD, TEM, N₂ adsorption-desorption, and magnetic measurements were conducted. Full article

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594 KiB

Open AccessArticle

Simultaneous Determination of 14 Phenolic Compounds in Grape Canes by HPLC-DAD-UV Using Wavelength Switching Detection

by Ang Zhang, Li Wan, Cuiyun Wu, Yulin Fang, Guomin Han, Hua Li, Zhenwen Zhang and Hua Wang

Molecules 2013, 18(11), 14241-14257; https://doi.org/10.3390/molecules181114241 - 18 Nov 2013

Cited by 78 | Viewed by 11493

Abstract

The paper described a novel chromatographic method for the simultaneous determination of phenolic compounds such as gallic, protocatechuic, vanillic, caffeic, syringic, p-coumaric and salicylic acid, (+)-catechin, (‒)-epicatechin, rutin, morin, quercetin, coumarin and trans-resveratrol at their maximum absorbance wavelengths (MAW) employing reverse-phase [...] Read more.

The paper described a novel chromatographic method for the simultaneous determination of phenolic compounds such as gallic, protocatechuic, vanillic, caffeic, syringic, p-coumaric and salicylic acid, (+)-catechin, (‒)-epicatechin, rutin, morin, quercetin, coumarin and trans-resveratrol at their maximum absorbance wavelengths (MAW) employing reverse-phase high performance liquid chromatography combined with DAD and UV detection via detection wavelength switching. The method was based on MAW acquisition by DAD and quantification by UV. The separation process was performed on a Shim-Pack VP-ODS C₁₈ column (250 mm × 4.6 mm, 5 μm) held at 30 °C, utilizing 3.0% acetic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL/min in the gradient elution mode. The method was fully validated in terms of linearity (r² > 0.9990, 10‒350 mg/L), precision (both intra-day and inter-day RSD < 4.22%), accuracy (97.31%‒104.66%), specificity, robustness (0.59% < RSD < 2.86%), limit of detection and quantification. The switching method significantly improved the sensitivities of most phenolics studied in comparison with the standard constant wavelength detection (280 nm). The proposed method has been successfully applied to the determination of 14 phenolic compounds in 89 varieties of one-year-old Chinese grape one-year-canes. Grape canes contain many phenolics, especially trans-resveratrol, (‒)-epicatechin, and (+)-catechin. Full article

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831 KiB

Open AccessArticle

Targeting C-myc G-Quadruplex: Dual Recognition by Aminosugar-Bisbenzimidazoles with Varying Linker Lengths

by Nihar Ranjan and Dev P. Arya

Molecules 2013, 18(11), 14228-14240; https://doi.org/10.3390/molecules181114228 - 18 Nov 2013

Cited by 35 | Viewed by 6738

Abstract

G-quadruplexes are therapeutically important biological targets. In this report, we present biophysical studies of neomycin-Hoechst 33258 conjugates binding to a G-quadruplex derived from the C-myc promoter sequence. Our studies indicate that conjugation of neomycin to a G-quadruplex binder, Hoechst 33258, enhances its [...] Read more.

G-quadruplexes are therapeutically important biological targets. In this report, we present biophysical studies of neomycin-Hoechst 33258 conjugates binding to a G-quadruplex derived from the C-myc promoter sequence. Our studies indicate that conjugation of neomycin to a G-quadruplex binder, Hoechst 33258, enhances its binding. The enhancement in G-quadruplex binding of these conjugates varies with the length and composition of the linkers joining the neomycin and Hoechst 33258 units. Full article

(This article belongs to the Special Issue G-Quadruplexes & i-Motif DNA)

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446 KiB

Open AccessReview

Investigating the Role of Polyunsaturated Fatty Acids in Bone Development Using Animal Models

by Beatrice Y.Y. Lau, Daniel J.A. Cohen, Wendy E. Ward and David W.L. Ma

Molecules 2013, 18(11), 14203-14227; https://doi.org/10.3390/molecules181114203 - 15 Nov 2013

Cited by 55 | Viewed by 7972

Abstract

Incorporating n-3 polyunsaturated fatty acids (PUFA) in the diet may promote the development of a healthy skeleton and thereby reduce the risk of developing osteoporosis in later life. Studies using developing animal models suggest lowering dietary n-6 PUFA and increasing n-3 PUFA intakes, [...] Read more.

Incorporating n-3 polyunsaturated fatty acids (PUFA) in the diet may promote the development of a healthy skeleton and thereby reduce the risk of developing osteoporosis in later life. Studies using developing animal models suggest lowering dietary n-6 PUFA and increasing n-3 PUFA intakes, especially long chain n-3 PUFA, may be beneficial for achieving higher bone mineral content, density and stronger bones. To date, the evidence regarding the effects of α-linolenic acid (ALA) remain equivocal, in contrast to evidence from the longer chain products, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This review reports the results of investigations into n-3 PUFA supplementation on bone fatty acid composition, strength and mineral content in developing animal models as well as the mechanistic relationships of PUFA and bone, and identifies critical areas for future research. Overall, this review supports a probable role for essential (ALA) and long chain (EPA and DHA) n-3 PUFA for bone health. Understanding the role of PUFA in optimizing bone health may lead to dietary strategies that promote bone development and maintenance of a healthy skeleton. Full article

(This article belongs to the Special Issue Fatty Acids)

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Open AccessArticle

Synthesis and Dual Histamine H₁ and H₂ Receptor Antagonist Activity of Cyanoguanidine Derivatives

by Bassem Sadek, Rudi Alisch, Armin Buschauer and Sigurd Elz

Molecules 2013, 18(11), 14186-14202; https://doi.org/10.3390/molecules181114186 - 15 Nov 2013

Cited by 14 | Viewed by 9663

Abstract

Premedication with a combination of histamine H₁ receptor (H₁R) and H₂ receptor (H₂R) antagonists has been suggested as a prophylactic principle, for instance, in anaesthesia and surgery. Aiming at pharmacological hybrids combining H₁R and H [...] Read more.

Premedication with a combination of histamine H₁ receptor (H₁R) and H₂ receptor (H₂R) antagonists has been suggested as a prophylactic principle, for instance, in anaesthesia and surgery. Aiming at pharmacological hybrids combining H₁R and H₂R antagonistic activity, a series of cyanoguanidines 14–35 was synthesized by linking mepyramine-type H₁R antagonist substructures with roxatidine-, tiotidine-, or ranitidine-type H₂R antagonist moieties. N-desmethylmepyramine was connected via a poly-methylene spacer to a cyanoguanidine group as the “urea equivalent” of the H₂R antagonist moiety. The title compounds were screened for histamine antagonistic activity at the isolated ileum (H₁R) and the isolated spontaneously beating right atrium (H₂R) of the guinea pig. The results indicate that, depending on the nature of the H₂R antagonist partial structure, the highest H₁R antagonist potency resided in roxatidine-type compounds with spacers of six methylene groups in length (compound 21), and tiotidine-type compounds irrespective of the alkyl chain length (compounds 28, 32, 33), N-cyano-N'-[2-[[(2-guanidino-4-thiazolyl)methyl]thio]ethyl]-N″-[2-[N-[2-[N-(4-methoxybenzyl)-N-(pyridyl)-amino] ethyl]-N-methylamino]ethyl] guanidine (25, pK_B values: 8.05 (H₁R, ileum) and 7.73 (H₂R, atrium) and the homologue with the mepyramine moiety connected by a six-membered chain to the tiotidine-like partial structure (compound 32, pK_B values: 8.61 (H₁R) and 6.61 (H₂R) were among the most potent hybrid compounds. With respect to the development of a potential pharmacotherapeutic agent, structural optimization seems possible through selection of other H₁R and H₂R pharmacophoric moieties with mutually affinity-enhancing properties. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessArticle

Secondary Metabolites in Durian Seeds: Oligomeric Proanthocyanidins

by Yuancai Liu, Shengbao Feng, Lixia Song, Guangyuan He, Mingjie Chen and Dejian Huang

Molecules 2013, 18(11), 14172-14185; https://doi.org/10.3390/molecules181114172 - 15 Nov 2013

Cited by 18 | Viewed by 7257

Abstract

Ethanolic extract of durian seeds was fractionated by reverse phase flash column chromatography and the fractions characterized by electrospray ionization mass spectroscopy. Among a few unknown compounds collected, oligomeric proanthocyanidins (OPCs) were found to be one of the main compounds. Based on this [...] Read more.

Ethanolic extract of durian seeds was fractionated by reverse phase flash column chromatography and the fractions characterized by electrospray ionization mass spectroscopy. Among a few unknown compounds collected, oligomeric proanthocyanidins (OPCs) were found to be one of the main compounds. Based on this result, the OPCs were purified the first time from the durian seeds using standard procedures and gave a yield of 1.8 mg/g dry matter after fractionation by Sephadex LH-20 column. Structural analysis by ¹³C{¹H} NMR and ESI-MS spectra showed the presence of primarily B-type procyanidins with mainly epicatechin as the extension units, which was further verified by matrix assisted laser desorption/ionization–time of flight mass spectra (MALDI-TOF MS), which shows a distribution of dimers to decamers. In addition, hydroxylated peaks with molecular weight 16 units more than the poly-epicatechins represented significant peaks. We suggest this might be due to hydroxylation occurring under the MALDI-TOF MS conditions. Consistently, depolymerization with α-toluenethiol resulted in epicatechin thioether as the major product, but undetectable amount of gallocatechin or its α-toluenethiol derivatives. The oligomershave a mean degree of polymerization of 7.30. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Applications of Lactobacillus rhamnosus Spent Culture Supernatant in Cosmetic Antioxidation, Whitening and Moisture Retention Applications

by Cheng-Chih Tsai, Chin-Feng Chan, Wen-Ying Huang, Jin-Seng Lin, Patty Chan, Ho-Yen Liu and Yung-Sheng Lin

Molecules 2013, 18(11), 14161-14171; https://doi.org/10.3390/molecules181114161 - 15 Nov 2013

Cited by 58 | Viewed by 10039

Abstract

This study was aimed at investigating the antioxidant, whitening, and moisture-retention properties of Lactobacillus rhamnosus spent culture supernatant (Lr-SCS) in cosmetic applications. Results reveal that Lr-SCS effectively and gradually scavenges 1,1-diphenyl-2-picrylhydrazyl as well as 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cations, and increases reducing power in [...] Read more.

This study was aimed at investigating the antioxidant, whitening, and moisture-retention properties of Lactobacillus rhamnosus spent culture supernatant (Lr-SCS) in cosmetic applications. Results reveal that Lr-SCS effectively and gradually scavenges 1,1-diphenyl-2-picrylhydrazyl as well as 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cations, and increases reducing power in a dose-dependent manner. Additionally, Lr-SCS can also suppress tyrosinase activity in vitro and effectively promote moisture retention. Heat treatment at 100 °C for 30 min does not influence the functions of Lr-SCS. We conclude that Lr-SCS can be used effectively in skin care cosmetics. Full article

(This article belongs to the Section Molecular Diversity)

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Open AccessConcept Paper

Topography of Photochemical Initiation in Molecular Materials

by Edward D. Aluker, Alexander G. Krechetov, Anatoly Y. Mitrofanov, Anton S. Zverev and Maija M. Kuklja

Molecules 2013, 18(11), 14148-14160; https://doi.org/10.3390/molecules181114148 - 15 Nov 2013

Cited by 24 | Viewed by 5897

Abstract

We propose a fluctuation model of the photochemical initiation of an explosive chain reaction in energetic materials. In accordance with the developed model, density fluctuations of photo-excited molecules serve as reaction nucleation sites due to the stochastic character of interactions between photons and [...] Read more.

We propose a fluctuation model of the photochemical initiation of an explosive chain reaction in energetic materials. In accordance with the developed model, density fluctuations of photo-excited molecules serve as reaction nucleation sites due to the stochastic character of interactions between photons and energetic molecules. A further development of the reaction is determined by a competition of two processes. The first process is growth in size of the isolated reaction cell, leading to a micro-explosion and release of the material from the cell towards the sample surface. The second process is the overlap of reaction cells due to an increase in their size, leading to the formation of a continuous reaction zone and culminating in a macro-explosion, i.e., explosion of the entire area, covering a large part of the volume of the sample. Within the proposed analytical model, we derived expressions of the explosion probability and the duration of the induction period as a function of the initiation energy (exposure). An experimental verification of the model was performed by exploring the initiation of pentaerythritol tetranitrate (PETN) with the first harmonic of YAG: Nd laser excitation (1,064 nm, 10 ns), which has confirmed the adequacy of the model. This validation allowed us to make a few quantitative assessments and predictions. For example, there must be a few dozen optically excited molecules produced by the initial fluctuations for the explosive decomposition reaction to occur and the life-time of an isolated cell before the micro-explosion must be of the order of microseconds. Full article

(This article belongs to the Special Issue Surface Chemistry)

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Open AccessArticle

Three New Germacrane-Type Sesquiterpenes with NGF-Potentiating Activity from Valeriana officinalis var. latiofolia

by Heng-Wen Chen, Li Chen, Bin Li, Hai-Long Yin, Ying Tian, Qiong Wang, Yan-Hua Xiao and Jun-Xing Dong

Molecules 2013, 18(11), 14138-14147; https://doi.org/10.3390/molecules181114138 - 14 Nov 2013

Cited by 16 | Viewed by 5914

Abstract

Three new germacrane-type sesquiterpenoids, volvalerenal F (1), volvalerenal G (2) and volvalerenic acid D (3), along with five known compounds 4–8, were isolated from the CHCl₃ soluble partition of the ethanol extract of [...] Read more.

Three new germacrane-type sesquiterpenoids, volvalerenal F (1), volvalerenal G (2) and volvalerenic acid D (3), along with five known compounds 4–8, were isolated from the CHCl₃ soluble partition of the ethanol extract of Valeriana officinalis var. latiofolia. The structures of the new compounds were determined on the basis of spectroscopic evidence, including their 1D- and 2D-NMR spectra, as well as mass spectrometry. The eight germacrane-type sesquiterpenoids showed nerve growth factor (NGF) potentiating activity, which mediates the neurite outgrowth in PC 12D cells. This study intends to reveal the chemical basis of the use of V. officinalis var. latiofolia as a dietary supplement. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessReview

Polymeric Systems of Antimicrobial Peptides—Strategies and Potential Applications

by Marcin Sobczak, Cezary Dębek, Ewa Olędzka and Ryszard Kozłowski

Molecules 2013, 18(11), 14122-14137; https://doi.org/10.3390/molecules181114122 - 14 Nov 2013

Cited by 68 | Viewed by 6960

Abstract

The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs). One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their [...] Read more.

The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs). One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their potential applications in the biomedical and pharmaceutical fields. Full article

(This article belongs to the Section Organic Chemistry)

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Open AccessArticle

Chemical Composition and Antioxidant Activity of Tánara Ótó (Dracocephalum palmatum Stephan), a Medicinal Plant Used by the North-Yakutian Nomads

by Daniil N. Olennikov, Nadezhda K. Chirikova, Zhanna M. Okhlopkova and Ismayl S. Zulfugarov

Molecules 2013, 18(11), 14105-14121; https://doi.org/10.3390/molecules181114105 - 14 Nov 2013

Cited by 56 | Viewed by 8423

Abstract

Dracocephalum palmatum Stephan (Lamiaceae) is a medicinal plant used by the North-Yakutian nomads. From the crude ethanolic extract of the aerial parts of this plant, 23 compounds (phenylpropanoids, coumarins, flavonoids, and triterpenes) were isolated. Among these, eight compounds (salvianolic acid B, caftaric acid, [...] Read more.

Dracocephalum palmatum Stephan (Lamiaceae) is a medicinal plant used by the North-Yakutian nomads. From the crude ethanolic extract of the aerial parts of this plant, 23 compounds (phenylpropanoids, coumarins, flavonoids, and triterpenes) were isolated. Among these, eight compounds (salvianolic acid B, caftaric acid, cichoric acid, umbelliferone, aesculetin, apigenin-7-O-β-d-glucuronopyranoside, isorhoifolin, and luteolin-4'-O-β-d-glucopyranoside) were detected for the first time in the genus Dracocephalum. Their structures were elucidated based on chemical and spectral data. The levels of most of the compounds detected in the cultivated sample were close to that of the wild sample, indicating the reproducibility of the biologically active compounds of D. palmatum through cultivation. Investigation into the biological activity of D. palmatum under in vitro conditions demonstrated that its extracts have a strong antioxidant effect due to the presence of high concentrations of phenolic compounds. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Bioactive Quinic Acid Derivatives from Ageratina adenophora

by Mei Zhang, Wan-Xue Liu, Meng-Fei Zheng, Qiao-Lin Xu, Fang-Hao Wan, Jing Wang, Ting Lei, Zhong-Yu Zhou and Jian-Wen Tan

Molecules 2013, 18(11), 14096-14104; https://doi.org/10.3390/molecules181114096 - 14 Nov 2013

Cited by 63 | Viewed by 8204

Abstract

A novel quinic acid derivative, 5-O-trans-o-coumaroylquinic acid methyl ester (1), together with three known ones, chlorogenic acid methyl ester (2), macranthoin F (3) and macranthoin G (4), were isolated [...] Read more.

A novel quinic acid derivative, 5-O-trans-o-coumaroylquinic acid methyl ester (1), together with three known ones, chlorogenic acid methyl ester (2), macranthoin F (3) and macranthoin G (4), were isolated from the aerial parts of the invasive plant Ageratina adenophora (Spreng.). The structure of new compound 1 was elucidated on the basis of extensive spectroscopic analysis, including 1D- and 2D-NMR techniques. Compounds 2–4 were isolated from plant A. adenophora for the first time. All the compounds showed in vitro antibacterial activity toward five assayed bacterial strains, especially 3 and 4, which showed in vitro antibacterial activity against Salmonella enterica with MIC values of 7.4 and 14.7 μM, respectively. Compound 1 was further found to display in vitro anti-fungal activity against spore germination of Magnaporthe grisea with an IC₅₀ value 542.3 µM. These four compounds were also tested for their antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radical. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

The Histone Deacetylase Inhibitors MS-275 and SAHA Suppress the p38 Mitogen-Activated Protein Kinase Signaling Pathway and Chemotaxis in Rheumatoid Arthritic Synovial Fibroblastic E11 Cells

by Qiu-Yi Choo, Paul C Ho, Yoshiya Tanaka and Hai-Shu Lin

Molecules 2013, 18(11), 14085-14095; https://doi.org/10.3390/molecules181114085 - 14 Nov 2013

Cited by 27 | Viewed by 6620

Abstract

MS-275 (entinostat) and SAHA (vorinostat), two histone deacetylase (HDAC) inhibitors currently in oncological trials, have displayed potent anti-rheumatic activities in rodent models of rheumatoid arthritis (RA). To further elucidate their anti-inflammatory mechanisms, the impact of MS-275 and SAHA on the p38 mitogen-activated protein [...] Read more.

MS-275 (entinostat) and SAHA (vorinostat), two histone deacetylase (HDAC) inhibitors currently in oncological trials, have displayed potent anti-rheumatic activities in rodent models of rheumatoid arthritis (RA). To further elucidate their anti-inflammatory mechanisms, the impact of MS-275 and SAHA on the p38 mitogen-activated protein kinase (MAPK) signaling pathway and chemotaxis was assessed in human rheumatoid arthritic synovial fibroblastic E11 cells. MS-275 and SAHA significantly suppressed the expression of p38α MAPK, but induced the expression of MAPK phosphatase-1 (MKP-1), an endogenous suppressor of p38α in E11 cells. At the same time, the association between p38α and MKP-1 was up-regulated and consequently, the activation (phosphorylation) of p38α was inhibited. Moreover, MS-275 and SAHA suppressed granulocyte chemotactic protein-2 (GCP-2), monocyte chemotactic protein-2 (MCP-2) and macrophage migration inhibitory factor (MIF) in E11 cells in a concentration-dependent manner. Subsequently, E11-driven migration of THP-1 and U937 monocytes was inhibited. In summary, suppression of the p38 MAPK signaling pathway and chemotaxis appear to be important anti-rheumatic mechanisms of action of these HDAC inhibitors. Full article

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Open AccessArticle

Design, Synthesis and Cytotoxic Activities of Novel Aliphatic Amino-Substituted Flavonoids

by Guannan Liu, Zhen Ge, Mengdan Zhao and Yifeng Zhou

Molecules 2013, 18(11), 14070-14084; https://doi.org/10.3390/molecules181114070 - 13 Nov 2013

Cited by 4 | Viewed by 5483

Abstract

A series of flavonoids 9a–f, 13b, 13d, 13e and 14a–f bearing diverse aliphatic amino moieties were designed, synthesized and evaluated for their cytotoxic activities against the ECA-109, A-549, HL-60, and PC-3 cancer cell lines. Most of [...] Read more.

A series of flavonoids 9a–f, 13b, 13d, 13e and 14a–f bearing diverse aliphatic amino moieties were designed, synthesized and evaluated for their cytotoxic activities against the ECA-109, A-549, HL-60, and PC-3 cancer cell lines. Most of the compounds exhibited moderate to good activities. The structure-activity relationships were studied, revealing that the chalcone skeleton is the most preferable for cytotoxic activities. Chalcone 9d was the most promising compound due to its high potency against the examined cancer cell lines (its IC₅₀ values against ECA-109, A549, HL-60 and PC-3 cells were 1.0, 1.5, 0.96 and 3.9 μM, respectively). Full article

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Open AccessReview

Molecular MRI of Atherosclerosis

by Alkystis Phinikaridou, Marcelo E. Andia, Sara Lacerda, Silvia Lorrio, Marcus R. Makowski and René M. Botnar

Molecules 2013, 18(11), 14042-14069; https://doi.org/10.3390/molecules181114042 - 13 Nov 2013

Cited by 26 | Viewed by 9247

Abstract

Despite advances in prevention, risk assessment and treatment, coronary artery disease (CAD) remains the leading cause of morbidity and mortality in Western countries. The lion’s share is due to acute coronary syndromes (ACS), which are predominantly triggered by plaque rupture or erosion and [...] Read more.

Despite advances in prevention, risk assessment and treatment, coronary artery disease (CAD) remains the leading cause of morbidity and mortality in Western countries. The lion’s share is due to acute coronary syndromes (ACS), which are predominantly triggered by plaque rupture or erosion and subsequent coronary thrombosis. As the majority of vulnerable plaques does not cause a significant stenosis, due to expansive remodeling, and are rather defined by their composition and biological activity, detection of vulnerable plaques with x-ray angiography has shown little success. Non-invasive vulnerable plaque detection by identifying biological features that have been associated with plaque progression, destabilization and rupture may therefore be more appropriate and may allow earlier detection, more aggressive treatment and monitoring of treatment response. MR molecular imaging with target specific molecular probes has shown great promise for the noninvasive in vivo visualization of biological processes at the molecular and cellular level in animals and humans. Compared to other imaging modalities; MRI can provide excellent spatial resolution; high soft tissue contrast and has the ability to simultaneously image anatomy; function as well as biological tissue composition and activity. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessCommunication

Synthesis of Some Green Dopants for OLEDs Based on Arylamine 2,3-disubstituted Bithiophene Derivatives

by Mi-Seon Song, Quynh Pham Bao Nguyen, Chang-Hyun Song, Duckhee Lee and Kyu Yun Chai

Molecules 2013, 18(11), 14033-14041; https://doi.org/10.3390/molecules181114033 - 13 Nov 2013

Cited by 5 | Viewed by 5326

Abstract

A series of green dopants based on 2,2-diphenylvinyl end-capped bithiophene and three different arylamine moieties (9-phenylcarbazole, triphenylamine, and N,N’-di-(p-tolyl)benzeneamine) were successfully synthesized by the Suzuki and Wittig coupling reactions. The photophysical properties of these compounds are reported. The strongest PL [...] Read more.

A series of green dopants based on 2,2-diphenylvinyl end-capped bithiophene and three different arylamine moieties (9-phenylcarbazole, triphenylamine, and N,N’-di-(p-tolyl)benzeneamine) were successfully synthesized by the Suzuki and Wittig coupling reactions. The photophysical properties of these compounds are reported. The strongest PL emitting compound with the 9-phenylcarbazole moiety has been used for fabricating an OLED device with good overall performance. Full article

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Open AccessArticle

Optimization of a Pre-MEKC Separation SPE Procedure for Steroid Molecules in Human Urine Samples

by Ilona Olędzka, Piotr Kowalski, Szymon Dziomba, Piotr Szmudanowski and Tomasz Bączek

Molecules 2013, 18(11), 14013-14032; https://doi.org/10.3390/molecules181114013 - 13 Nov 2013

Cited by 9 | Viewed by 5553

Abstract

Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and [...] Read more.

Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and labor-consuming and quite costly. Therefore, the aim of analytical laboratories is to develop a new, relatively low-cost and rapid implementation methodology for their determination in biological samples. Due to the fact that there is little literature data on concentrations of steroid hormones in urine samples, we have made attempts at the electrophoretic determination of these compounds. For this purpose, an extraction procedure for the optimized separation and simultaneous determination of seven steroid hormones in urine samples has been investigated. The isolation of analytes from biological samples was performed by liquid-liquid extraction (LLE) with dichloromethane and compared to solid phase extraction (SPE) with C₁₈ and hydrophilic-lipophilic balance (HLB) columns. To separate all the analytes a micellar electrokinetic capillary chromatography (MECK) technique was employed. For full separation of all the analytes a running buffer (pH 9.2), composed of 10 mM sodium tetraborate decahydrate (borax), 50 mM sodium dodecyl sulfate (SDS), and 10% methanol was selected. The methodology developed in this work for the determination of steroid hormones meets all the requirements of analytical methods. The applicability of the method has been confirmed for the analysis of urine samples collected from volunteers—both men and women (students, amateur bodybuilders, using and not applying steroid doping). The data obtained during this work can be successfully used for further research on the determination of steroid hormones in urine samples. Full article

(This article belongs to the Special Issue Steroids)

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Molecules, Volume 18, Issue 11 (November 2013) – 88 articles , Pages 13124-14454

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