Isoferulic Acid Research Articles

Antioxidants and α-glucosidase inhibitors from "Liucha" (young leaves and shoots of Sibiraea laevigata).

The young leaves and shoots of Sibiraea laevigata, known as "Liucha", are used as tea by Tibetans to improve digestion after meals. Long-term consumption of "Liucha" will cause weight loss. In present work, we reported on the isolation and NMR and chemical analysis-based elucidation of seven new sorbitol O-caffeic acid ester derivatives named sorbitol esters A-G (1-7) and eighteen known phenolic compounds from S. laevigata. All of the isolates were evaluated for their antioxidant and α-glucosidase inhibitory activities. Among them sorbitol ester A (1), sorbitol ester D (4), sorbitol ester F (6), sorbitol ester G (7), isoferulic acid (15), methyl caffeate (18), trans-p-hydroxycinnamic acid (19), and kaempferol 3-O-β-d-(6″-E-p-coumaroyl)-glucopyranoside (25) showed more potent α-glucosidase inhibitory activity than the clinical drug acarbose.

Cloning, Functional Characterization and Site-Directed Mutagenesis of 4-Coumarate: Coenzyme A Ligase (4CL) Involved in Coumarin Biosynthesis in Peucedanum praeruptorum Dunn.

Coumarins are the main bioactive compounds in Peucedanum praeruptorum Dunn, a common Chinese herbal medicine. Nevertheless, the genes involved in the biosynthesis of core structure of coumarin in P. praeruptorum have not been identified yet. 4-Coumarate: CoA ligase (4CL) catalyzes the formation of hydroxycinnamates CoA esters, and plays an essential role at the divergence point from general phenylpropanoid metabolism to major branch pathway of coumarin. Here, three novel putative 4CL genes (Pp4CL1, Pp4CL7, and Pp4CL10) were isolated from P. praeruptorum. Biochemical characterization of the recombinant proteins revealed that Pp4CL1 utilized p-coumaric and ferulic acids as its two main substrates for coumarin biosynthesis in P. praeruptorum. Furthermore, Pp4CL1 also exhibited activity toward caffeic, cinnamic, isoferulic, and o-coumaric acids and represented a bona fide 4CL. Pp4CL7 and Pp4CL10 had no catalytic activity toward hydroxycinnamic acid compounds. But they had close phylogenetic relationship to true 4CLs and were defined as 4CL-like genes. Among all putative 4CLs, Pp4CL1 was the most highly expressed gene in roots, and its expression level was significantly up-regulated in mature roots compared with seedlings. Subcellular localization studies showed that Pp4CL1 and Pp4CL10 proteins were localized in the cytosol. In addition, site-directed mutagenesis of Pp4CL1 demonstrated that amino acids of Tyr-239, Ala-243, Met-306, Ala-309, Gly-334, Lys-441, Gln-446, and Lys-526 were essential for substrate binding or catalytic activities. The characterization and site-directed mutagenesis studies of Pp4CL1 lays a solid foundation for elucidating the biosynthetic mechanisms of coumarins in P. praeruptorum and provides further insights in understanding the structure–function relationships of this important family of proteins.

INVESTIGATION OF PHENOLIC COMPOUNDS IN EXTRACTS FROM THE LEAVES OF LAURUS NOBILIS L.

Laurus nobilis L. is an evergreen dioecious, rarely monecious plant up to 15 m high. Its natural area includes Mediterranean countries. For a long time this plant has been actively cultivated as a decorative plant in (Europe, Russia, USA and others) as well as in Turkey, Algeria, Morocco, Spain, France, Italy, Portugal, Mexico and Russia. Chemical composition of the Laurus leaves include essential oil components, sesquiterpenic lactones and phenolic compounds as the principal active groups of compounds. The aim of the study was the identification of phenolic compounds in water and water alcohol extracts from leaves of Laurus nobilis. Materials and methods. Examinations of qualitative composition of phenolic complex in extracts from Laurus samples under study were carried out using «Hitachi Chromaster» high-performance liquid chromatographer with «Column Oven 5310», «Pump 5110» and «UV-detector 5410». Results and discussion . The samples of Laurus nobilis leaves gathered in outskirts of Alushta (Republic of Crimea) in July 2016 were the objects if the study. We identified caffeic, gallic, and chicoric acids, epigallocatechin gallate, luteolin-7-glycoside in the extracts obtained using ethanol 70%. And caffeic, gallic, isoferulic acids, dicoumarin, epicatechin, kaempferol, and isoquercitrin in ethanol 40% extracts. In water extracts we found the presence of ascorbic, gallic, and vanillic acids, epicatechin, quercetin-3-glycoside and kaempferol-3-galactoside. Conclusion . As the result of the Laurus nobilis leaves samples study, gathered in Alushta outskirts, ascorbic acid and 13 phenolic compounds were identified in water and water-alcohol (40% and 70%) extracts using high performance liquid chromatography. Isoferulic and chicoric acids, epigallocatechin gallate, dicoumarin, kaempferol, isoquercitrin, kaempferol-3-galactoside and luteolin-7-glycoside were identified in Laurus nobilis leaves for the first time.

Water stress induces changes in polyphenol profile and antioxidant capacity in poplar plants (Populus spp.)

This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO.

Isoferulic Acid Action against Glycation-Induced Changes in Structural and Functional Attributes of Human High-Density Lipoprotein.

Glycation-induced high-density lipoprotein (HDL) modification by aldehydes can result in loss of its antiinflammatory/antioxidative properties, contributing to diabetes-associated cardiovascular diseases. Isoferulic acid, a major active ingredient of Cimicifuga heracleifolia, shows antiinflammatory, antiviral, antioxidant, and antidiabetic properties. Thus, this study investigated the antiglycation effect of isoferulic acid against compositional modifications of HDL and loss of biological activity of HDL-paraoxonase induced on incubation with different aldehydes. Protective effect of isoferulic acid was assessed by subjecting purified HDL from human plasma to glycation with methylglyoxal, glyoxal, or glycolaldehyde and varying concentrations of isoferulic acid. The effect of isoferulic acid was analyzed by determining amino group number, tryptophan and advanced glycation end-product fluorescence, thermal denaturation studies, carboxymethyl lysine content, and activity of HDL-paraoxonase. Concentration-dependent inhibitory action of isoferulic acid was observed against extensive structural perturbations, decrease in amino group number, increase in carboxymethyl lysine content, and decrease in the activity of HDL-paraoxonase caused by aldehyde-associated glycation in the HDL molecule. Isoferulic acid, when taken in concentration equal to that of aldehydes, was most protective, as 82-88% of paraoxonase activity was retained for all studied aldehydes. Isoferulic acid shows antiglycation action against aldehyde-associated glycation in HDL, which indicates its therapeutic potential for diabetic patients, especially those with micro-/macrovascular complications.

Graphene quantum dots as additives in capillary electrophoresis for separation cinnamic acid and its derivatives

A facile capillary electrophoresis (CE) method for the separation of cinnamic acid and its derivatives (3,4-dimethoxycinnamic acid, 4-methoxycinnamic acid, isoferulic acid, sinapic acid, cinnamic acid, ferulic acid, and trans-4-hydroxycinnamic acid) using graphene quantum dots (GQDs) as additives with direct ultraviolet (UV) detection is reported. GQDs were synthesized by chemical oxidization and further purified by a macroporous resin column to remove salts (Na2SO4 and NaNO3) and other impurities. Transmission electron microscopy (TEM) indicated that GQDs have a relatively uniform particle size (2.3 nm). Taking into account the structural features of GQDs, cinnamic acid and its derivatives were adopted as model compounds to investigate whether GQDs can be used to improve CE separations. The separation performance of GQDs used as additives in CE was studied through variations of pH, concentration of the background electrolyte (BGE), and contents of GQDs. The results indicated that excellent separation can be achieved in less than 18 min, which is mainly attributed to the interaction between the analytes and GQDs, especially isoferulic acid, sinapic acid, and cinnamic acid.

Identification and quantification of novel cranberry-derived plasma and urinary (poly)phenols

Cranberries are a rich source of (poly)phenols, in particular proanthocyanidins, anthocyanins, flavonols, and phenolic acids. However, little is known about their bioavailability in humans. We investigated the absorption, metabolism, and excretion of cranberry (poly)phenols in plasma and urine of healthy young men after consumption of a cranberry juice (787 mg (poly)phenols). A total of 60 cranberry-derived phenolic metabolites were identified using UPLC-Q-TOF-MS analysis with authentic standards. These included sulfates of pyrogallol, valerolactone, benzoic acids, phenylacetic acids, glucuronides of flavonols, as well as sulfates and glucuronides of cinnamic acids. The most abundant plasma metabolites were small phenolic compounds, in particular hippuric acid, catechol-O-sulfate, 2,3-dihydroxybenzoic acid, phenylacetic acid, isoferulic acid, 4-methylcatechol-O-sulfate, α-hydroxyhippuric acid, ferulic acid 4-O-sulfate, benzoic acid, 4-hydroxyphenyl acetic acid, dihydrocaffeic acid 3-O-sulfate, and vanillic acid-4-O-sulfate. Some benzoic acids, cinnamic acids, and flavonol metabolites appeared in plasma early, at 1–2 h post-consumption. Others such as phenylacetic acids, benzaldehydes, pyrogallols, catechols, hippuric and dihydrocinnamic acid derivatives appear in plasma later (Tmax 4–22 h). The 24 h urinary recovery with respect to the amount of (poly)phenols consumed was 6.2%. Our extensive description of the bioavailability of cranberry (poly)phenols lays important groundwork necessary to start understanding the fate of these compounds in humans.

Antioxidative free and bound phenolic constituents in botanical fractions of Indian specialty maize (Zea mays L.) genotypes

Specialty maize genotypes viz. QPM (quality protein maize), Baby corn, Popcorn and Sweet corn, which are usually consumed in whole forms can be good supplements of phenolic antioxidants. Botanical fractions of these maize genotypes were analyzed to explore the distribution of free and bound phenolics. HPLC and ESI-MS/MS results indicated the presence of vanillic, syringic, p-hydroxybenzoic, caffeic, p-coumaric, ferulic and isoferulic acids along with cyanidin-3-O-glucoside, kaempferol and quercetin. Germs of maize samples contained significantly higher free phenolics than pericarps, whereas, pericarps contained 74–83% of bound ones. QPM and Popcorn contained only 3% free phenolics whereas, Baby corn and Sweet corn had 14–17%. Unlike in peroxide scavenging and reducing capacity, anti-radical capacity of free phenolics of germs was significantly higher than that of pericarps. Free phenolics contributed 0.2–1.65%, 2–5% and 42–49% in anti-radical, peroxide scavenging and reducing capacity, respectively. Among lipophilic tocochromanols γ-tocopherol was the most abundant isomer in the samples among which Sweet corn contained the most (84.2μg/g). Data showed that specialty maize genotypes are rich sources of hydrophilic and lipophilic bioactives and are natural antioxidants.

Preparative separation of polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin coupled with preparative high performance liquid chromatography.

In this study, a preparative separation method was developed for isolation of eleven polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin (MAR) coupled with preparative high performance liquid chromatography (PHPLC). Water-soluble fraction of Chinese propolis was first "prefractioned" using MAR, which yielded four subfractions. The four subfractions were then isolated by PHPLC with an isocratic elution of methanol-water. Finally, eleven polyphenols were purified from Chinese propolis including caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxy cinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin and galangin. The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. The method developed was simple, effective, rapid, scalable and economical, and it was a promising basis for large-scale preparation of multiple components from natural products.

Bioactive Components of Chinese Propolis Water Extract on Antitumor Activity and Quality Control.

To understand the material basis of antitumor activity of Chinese propolis water extract (CPWE), we developed a simple and efficient method using macroporous absorptive resin coupled with preparative high performance liquid chromatography and separated and purified eleven chemical components (caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin, and galangin) from CPWE; then we tested the antitumor activities of these eleven components using different human tumor cell lines (MCF-7, MDA-MB-231, HeLa, and A549). Furthermore, cell migration, procaspase 3 level, and reactive oxygen species (ROS) of effective components from CPWE were investigated. Our data showed that antitumor activities of the eleven components from CPWE were different from each other. CPWE and its effective components induced apoptosis by inhibiting tumor cell migration, activating caspase 3, and promoting ROS production. It can be deduced that the antitumor effects of propolis did not depend on a single component, and there must exist “bioactive components,” which also provides a new idea for Chinese propolis quality control.

Phenolic Assesment of Uncaria tomentosa L. (Cat's Claw): Leaves, Stem, Bark and Wood Extracts.

The phenolic composition of extracts from Uncaria tomentosa L. from different regions of Costa Rica was studied using advanced analytical techniques such as UPLC/TQ-ESI-MS and 13C-NMR. Samples from leaves, stems, bark and wood (n = 22) were subjected to extraction to obtain phenolic and alkaloid extracts, separately. Comparatively, higher values of total phenolic content were observed for leaves, stems and bark (225–494 gallic acid equivalents/g) than for wood extracts (40–167 gallic acid equivalents/g). A total of 32 non-flavonoid and flavonoid compounds were identified in the phenolic extracts: hydroxybenzoic acids (benzoic, salicylic, 4-hydroxybenzoic, prochatechuic, gallic, syringic and vanillic acids), hydroxycinnamic acids (p-coumaric, caffeic, ferulic and isoferulic acids), flavan-3-ols monomers [(+)-catechin and (−)-epicatechin)], procyanidin dimers (B1, B2, B3, B4, B5, B7 and two other of unknown structure) and trimers (C1, T2 and one of unknown structure), flavalignans (four unknown structures pertaining to the cinchonain family) and propelargonidin dimers (four unknown structures, reported for the first time in U. tomentosa). Additionally, alkaloid extracts obtained from the plant residue after phenolic extraction exhibited a content of tetracyclic and pentacyclic alkaloids ranging between 95 and 275 mg/100 g of dry material for bark extracts, and between 30 and 704 mg/100 g for leaves extracts. In addition, a minor alkaloid was isolated and characterized, namely 18,19-dehydrocorynoxinoic acid. Our results confirmed the feasibility of U. tomentosa as a suitable raw material for obtaining phenolic- and alkaloid-rich extracts of potential interest.

New insights into the bioavailability of red raspberry anthocyanins and ellagitannins

Red raspberries, containing ellagitannins and cyanidin-based anthocyanins, were fed to volunteers and metabolites appearing in plasma and urine were analysed by UHPLC-MS. Anthocyanins were not absorbed to any extent with sub nmol/L concentrations of cyanidin-3-O-glucoside and a cyanidin-O-glucuronide appearing transiently in plasma. Anthocyanins excreted in urine corresponded to 0.007% of intake. More substantial amounts of phase II metabolites of ferulic acid and isoferulic acid, along with 4′-hydroxyhippuric acid, potentially originating from pH-mediated degradation of cyanidin in the proximal gastrointestinal tract, appeared in urine and also plasma where peak concentrations were attained 1–1.5h after raspberry intake. Excretion of 18 anthocyanin-derived metabolites corresponded to 15.0% of intake, a figure substantially higher than obtained in other anthocyanin feeding studies. Ellagitannins pass from the small to the large intestine where the colonic microbiota mediate their conversion to urolithins A and B which appeared in plasma and were excreted almost exclusively as sulfate and glucuronide metabolites. The urolithin metabolites persisted in the circulatory system and were excreted in urine for much longer periods of time than the anthocyanin metabolites although their overall urinary recovery was lower at 7.0% of intake. It is events originating in the proximal and distal gastrointestinal tract, and subsequent phase II metabolism, that play an important role in the bioavailability of both anthocyanins and ellagitannins and it is their metabolites which appear in the circulatory system, that are key to elucidating the mode of action(s) underlying the protective effects of these compounds on human health.

Isoferulic acid prevents methylglyoxal-induced protein glycation and DNA damage by free radical scavenging activity.

BackgroundIsoferulic acid (IFA), a naturally occurring cinnamic acid derivative, is a main active ingredient of the rhizoma of Cimicifuga dahurica. It has been shown various pharmacological activities. The aim of the study was to investigate the effect of IFA against MG-induced protein glycation and oxidative DNA damage. Free radical scavenging activity and the MGO-trapping abilities of IFA were also investigated.MethodsThe fluorescent MG-derived AGEs and non-fluorescent Nε-(carboxymethyl) lysine (Nε-CML) was measured using a spectrofluorometer and an enzyme linked immunosorbant assay (ELISA). Protein carbonyl content was used to detect protein oxidation. Gel electrophoresis was used to determine DNA damage. Superoxide anion radicals and hydroxyl radicals were determined using cytochrome c reduction assay and thiobarbituric acid reactive 2-deoxy-D-ribose oxidation products, respectively. The MG-trapping capacity was performed by HPLC.ResultsIFA (1.25–5 mM) inhibited the formation of fluorescent MG-derived AGEs, and Nε-CML, and protein carbonyl in bovine serum albumin. In addition, IFA (0.1–1 mM) also prevented MG/lysine-mediated oxidative DNA damage in the presence and absence of copper ion. The protective ability of IFA was directly correlated to inhibition of hydroxyl and superoxide anion radical generation during the reaction of MG and lysine. Most notably, IFA had no the directly trapping ability to MG.ConclusionsThe present results highlighted that free radical scavenging activity, but not the MG-trapping ability, is the mechanism of IFA for preventing MG-induced protein glycation and DNA damage.

P-Methoxycinnamic acid, an active phenylpropanoid induces mitochondrial mediated apoptosis in HCT-116 human colon adenocarcinoma cell line.

Among the eight phytochemicals (dihydrocarveol, sinapic acid, vanillic acid, ethylgallate, myrtenol, transcarveol, p-methoxycinnamic acid, and isoferulic acid) we tested, p-methoxycinnamic acid (p-MCA) [10 μM] showed the most potent in vitro growth inhibition on human colon adenocarcinoma (HCT-116 cells). Antiproliferative activity of p-MCA at 24h was associated with DNA damage, morphological changes and the results were comparable with doxorubicin. p-MCA induced phosphatidylserine translocation, increased the levels of reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCC) and decreased enzymic antioxidant status (SOD, CAT, GPx) in HCT-116. p-MCA treatment increased the percentage of apoptotic cells, decreased the mitochondrial membrane potential and triggered cytochrome C release to cytosol. The induction of apoptosis by p-MCA was accompanied by an increase in caspase 3 and caspase 9 activities, increased expression of Bax and decreased expression of Bcl-2. Thus p-MCA induces mitochondria mediated intrinsic pathway of apoptosis in HCT-116 and has potential for treatment and prevention of colon cancer.

Phenolic constituents from <i>Sarcopyramis nepalensis</i> and their α-Glucosidase inhibitory activity

Background: This study was carried out to fully investigate the phenolic chemical constituents of Sarcopyramis nepalensis and determine their α-glucosidase inhibitory activity.Materials and Methods: S. nepalensis was extracted using the ultrasonic assistant extraction (UAE) method and further fractionated with petroleum ether (PE), chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH), respectively. The active fraction was chromatographed on AB-8 macroporous resin column, silica gel column, Sephadex LH-20 column, RP-ODS column and semi-preparative HPLC column. The isolated phenolic constituents were identified by 1H-Nuclear Magnetic Resonance (NMR), 13C-NMR and mass spectral (MS) analyses and detected their α-glucosidase inhibitory activity by micro-plate.Results: Ten phenolic constituents were isolated and identified from the active fraction of S. nepalensis. They were identified as isorhamnetin(1), quercetin(2), isorhamnetin-3-O-β-D-glucopyranoside(3), isoquercetin (4), astragalin(5),isorhamnetin-3-O-(6"-p-coumaroyl)-β-D-glucopyranoside(6),isorhamnetin-3-O-(6"-caffeoyl)-β-D-glucopyranoside(7), isoferulic acid(8) Caffeic acid(9) and ellagic acid(10). All of the phenolic compounds were assayed for their hypoglycemic activity against α-glucosidase in vitro. Compound 4, 6 and 7 showed promising α-glucosidase inhibitory activity with the IC50 values of 0.69 mg/ml, 0.56 mg/ml, 0.45 mg/ml, respectively.Conclusion: Compounds 5-8 were isolated for the first time from S. nepalensis. This is the first report on the characterization of phenolic compounds and possible utilization of S. nepalensis for therapeutic intervention in type 2 diabetes.Key words: α-glucosidase inhibitory, Phenolic constituents, Sarcopyramis nepalensis

Metabolism of Chuanxiong Rhizoma decoction: Identification of the metabolites in WZS-miniature pig urine

Chuanxiong Rhizoma (CR), a well-known traditional Chinese medicine originated from the rhizome of Ligusticum chuanxiong Hort., was effective for treating various vascular diseases. To identify the metabolites of CR in vivo, the drug-containing urine samples of WZS-miniature pigs after orally administrated CR decoction were collected, after sequential column chromatography 17 metabolites (M1–M17) were isolated from the methanol extract of the urine samples. Their structures, including nine phthalides (M1–M9) and eight phenolic acids (M10–M17), were identified by spectroscopic means. Among them, 8 were new ones (M1–M6, M11–M12). On the basis of the structures of identified metabolites, seven original constituents, including 2 phthalides (senkyunolideI/H) and 5 phenolic acids (ferulic acid, isoferulic acid, caffeic acid, 3-hydroxycinnamoyl acid and 4-hydroxybenzonic acid) were deduced to be the major absorbed original constituents of CR in vivo. This is the first study on the metabolites of CR decoction in non-rodent animal (WZS-miniature pig), the results will give an insight into the metabolism profiles of phthalides and phenolic acids in CR decoction in vivo.

Gastroprotective activity of the hydroethanolic extract and isolated compounds from the leaves of Solanum cernuum Vell.

Ethnopharmacological relevanceSolanum cernuum Vell. (Solanaceae) is a Brazilian medicinal plant, traditionally known as “panaceia”. Its folk name is probably due to its wide range of applications in traditional medicine including the treatment of ulcers. Aim of the studyTo evaluate the gastroprotective activities of the hydroethanolic extract (ESC) of S. cernuum and its major isolated compounds using in vivo gastric ulcer models. Material and methodsThe ESC extract was obtained by maceration followed by percolation of the dried and powdered leaves of S. cernuum in ethanol:water (7:3). The major compounds in the extract were isolated by applying various preparative chromatographic techniques. The gastroprotective activity was evaluated in mice using different gastric ulcer-induced models. The anti-Helicobacter pylori activity was performed using the agar-well diffusion and broth microdilution methods. ResultsThe ESC extract showed gastroprotective effects in the assay of acute gastric ulcer-induced by HCl/EtOH, nonsteroidal anti-inflammatory drug, and acetic acid-induced chronic ulcer protocols. The results also demonstrated that the gastroprotection induced by ESC extract is related to the activity of nitric oxide and endogenous sulfhydryls, which are important gastroprotective factors. The ESC extract and the alkaloid cernumidine did not show activity against H. pylori in the concentrations tested. ConclusionsThe present study showed that the crude extract of S. cernuum possessed gastroprotective activity which corroborating the traditional use of this plant for the treatment of gastric ulcers. The isolated flavonoids, quercitrin and afzelin as well as the phenylpropanoid, isoferulic acid are suggested to be the compounds responsible for the gastroprotective activity of S. cernuum extract.

PHENOLIC CONSTITUENTS FROM SARCOPYRAMIS NEPALENSIS AND THEIR Α-GLUCOSIDASE INHIBITORY ACTIVITY

Background: This study was carried out to fully investigate the phenolic chemical constituents of Sarcopyramis nepalensis and determine their α-glucosidase inhibitory activity. 
 Materials and Methods: S. nepalensis was extracted using the ultrasonic assistant extraction (UAE) method and further fractionated with petroleum ether (PE), chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH), respectively. The active fraction was chromatographed on AB-8 macroporous resin column, silica gel column, Sephadex LH-20 column, RP-ODS column and semi-preparative HPLC column. The isolated phenolic constituents were identified by 1H-Nuclear Magnetic Resonance (NMR), 13C-NMR and mass spectral (MS) analyses and detected their α-glucosidase inhibitory activity by micro-plate. 
 Results: Ten phenolic constituents were isolated and identified from the active fraction of S. nepalensis. They were identified as isorhamnetin(1), quercetin(2), isorhamnetin-3-O-β-D-glucopyranoside(3), isoquercetin (4), astragalin(5),isorhamnetin-3-O-(6"-p-coumaroyl)-β-D-glucopyranoside(6),isorhamnetin-3-O-(6"-caffeoyl)-β-D-glucopyranoside(7), isoferulic acid(8) Caffeic acid(9) and ellagic acid(10). All of the phenolic compounds were assayed for their hypoglycemic activity against α-glucosidase in vitro. Compound 4, 6 and 7 showed promising α-glucosidase inhibitory activity with the IC50 values of 0.69 mg/ml, 0.56 mg/ml, 0.45 mg/ml, respectively.
 Conclusion: Compounds 5-8 were isolated for the first time from S. nepalensis. This is the first report on the characterization of phenolic compounds and possible utilization of S. nepalensis for therapeutic intervention in type 2 diabetes.

Inhibition screening method of microsomal UGTs using the cocktail approach

A rapid method for the simultaneous determination of the in vitro activity of the 10 major human liver UDP-glucuronosyltransferase (UGT) enzymes was developed based on the cocktail approach. Specific substrates were first selected for each UGT: etoposide for UGT1A1, chenodeoxycholic acid for UGT1A3, trifluoperazine for UGT1A4, serotonin for UGT 1A6, isoferulic acid for UGT1A9, codeine for UGT2B4, azidothymidine for UGT2B7, levomedetomidine for UGT2B10, 4-hydroxy-3-methoxymethamphetamine for UGT2B15 and testosterone for UGT2B17. Optimal incubation conditions, including time-based experiments on cocktail metabolism in pooled HLMs that had been performed, were then investigated. A 45-min incubation period was found to be a favorable compromise for all the substrates in the cocktail. Ultra-high pressure liquid chromatography coupled to an electrospray ionization time-of-flight mass spectrometer was used to separate the 10 substrates and their UGT-specific glucuronides in less than 6min. The ability of the cocktail to highlight the UGT inhibitory potential of xenobiotics was initially proven by using well-known UGT inhibitors (selective and nonselective) and then by relating some of the screening results obtained by using the cocktail approach with morphine glucuronidation (substrate highly glucuronidated by UGT 2B7). All the results were in agreement with both the literature and with the expected effect on morphine glucuronidation.

Phenolic acids of native species of the Rosa L. genus in Poland

Phenolic acids were identified in the leaves of 23 species of native roses and their quantitative proportions were determined by the method of two-dimensional paper chromatography. The common occurrence of ellagic and gallic acid in roses was confirmed and so was the regular presence of protocatechuic, caffeic, gentisic, p-hydroxybenzoic, p-hydroxyphenylacetic, p-cumaric, syringic, vanillic, ferulic and salicylic acids. A small amount of isoferulic acid was noted only in <i>Rosa gizellae</i> Borb. and <i>R. eglanteria</i> L. var. <i>comosa</i> (Ripart) Du Mortier. Homoprotocatechuic acid was revealed only in the species of the <i>Rosa rubiginosa</i> and <i>Rosa tomentosa</i> groups from the <i>Caninae </i>section. The taxonomically limited occurrence of some phenolic acids points to the systematic differentiating value of the latter within one genus.