OBJECTIVETo study chemical constituents in nutshell of Trapa acornis and in vitro inhibitory activity against alpha-glucosidase.

METHODEtOAC and n-butanol extractive fractions were separated by chromatography and their structures were identified by multiple spectroscopic techniques.

RESULTNine compounds were separated, they were 4,23,24-trimethylcholest-22-en-3-ol (1), stigmasterol (2), alpha-amyrin (3), (+)-nyasol (4), oleanolic acid (5), ursolic acid (6), hederagenin (7), 3,23-dihydroxy-12-ursen-28-oic acid (8) and beta-daucosterol (9). Total extracts from T. acornis nutshells, petroleum ether fractions, acetic ether fractions and normal butanol fractions showed inhibitory activity against alpha-glucosidase. Compound 5 (IC50 2.88 mg x L(-1)) and 6 (IC50 4.42 mg L(-1)) showed stronger inhibitory activity against alpha-glucosidase.

CONCLUSIONAll compounds except compound 2 were separated from the genus for the first time, and compound 1-9 were separated from this plant for the first time.

Enzyme Inhibitors ; chemistry ; Glycoside Hydrolase Inhibitors ; Lythraceae ; chemistry

A trienzyme extraction method (use of alpha-amylase, protease and folate conjugase) for food folate assay has been used to release folate from the food matrix. In order to reduce the incubation time with three enzymes, folate values were compared between two incubation protocols; separate incubation (SI, incubated with alpha-amylase and conjugase separately for 2 hours after protease treatment) and combined incubation (CI, incubated with alpha-amylase and conjugase together for 2 hours after protease treatment) using 88 food items from 12 kinds of fast foods and processed foods. We found that folate values by CI were comparable to or higher than those by SI, indicating that CI might be a better extraction procedure to shorten the entire incubation time. We measured folate contents in 49 fast foods and 26 processed foods by microbiological assay after CI. Mean folate contents of one serving of various burgers ranged from 43.1 to 62.0 microgram. One serving of French fries, pizza, sandwich and triangled kimbab contained a mean of 53.3, 28.4, 47.4, and 25.7 microgram of folate, respectively. Folate contents of non-alcoholic beverages were very low, ranging from 1.0 to 5.2 microgram/100 g. Some of our values were comparable to the values in the folate database published in Korean Nutrition Society, however, some of the published values were 140 times higher than the measured values in this study. Folate values measured by the more recent modifications here can be used to update Korean folate database to accurately estimate dietary folate intake
alpha-Amylases ; Beverages ; Fast Foods ; Folic Acid ; gamma-Glutamyl Hydrolase

OBJECTIVETo study the mechanism of lactose intolerance (LI) by cloning the mouse lactase cDNA and recombining a vector. METHODS Total murine RNA was isolated from the small intestine of a 4-week-old BALB/c mouse (d). Gene-specific primers were designed and synthesized according to the cDNA sequences of lactase-phlorizin hydrolase (LPH) in human, rat, and rabbit. A coding sequence (CDS) fragment was obtained using RT-PCR, and inserted into a clone vector pNEB-193, then the cDNA was sequenced and analyzed using bioinformatics.

RESULTSThe cDNA from the BALB/c mouse with 912 bp encoding 303 amino acid residues. Analysis of the deduced amino acid sequence using bioinformatics revealed that this cDNA shared extensive sequence homology with human LPH containing a conserved glycosyl hydrolase family 1 motif important for regulating lactase intolerance.

CONCLUSIONBALB/c mouse LPH cDNA (GenBank accession No: AY751548) provides a necessary foundation for study of the biological function and regulatory mechanism of the lactose intolerance in mice.

Animals ; Cloning, Molecular ; DNA, Complementary ; Humans ; Lactase-Phlorizin Hydrolase ; genetics ; Mice ; Mice, Inbred BALB C

OBJECTIVETo study the inhibitory activity of Aeschynanthus maculatus on alpha-glucosidase.

METHODThe inhibilitory model of in vitro alpha-glucosidase was established. Active extracts of A. maculatus were isolated and identified bymultiple chromatographic methods, and their molecular structures were identifiied by spectral techniques.

RESULTSeven coumpounts were isolated from A. maculatus and isolated as lupeol(1), stigmasterol(2), ursolic acid(3), stigmast-5,22(E)-diene-3beta-ol(4), beta-daucosterol(5), 3-hydroxy-12-taraxasten-28-oic-acid(6) and oleanic acid(7). Compounds 1 (IC50 25.41 mg x L(-1)),3(IC0 4.42 mg L(-1)),4(IC50 11.50 mg x L(-1)),6(IC50 14.17 mg x L(-1)) and 7(IC50 2.88 mg x L(-1)) had higher inhibitory activities than that of acarbose (IC50 1103.01 mg x L(-1)) as the positive control drug.

CONCLUSIONCompound 1-7 were isolated from this plant for the first time. Compound 6 was isolated from Gesneriaceae family for the first time. Compound 7 was isolated from Aeschynanthus genus for the first time.

Enzyme Inhibitors ; chemistry ; pharmacology ; Ferns ; chemistry ; Glycoside Hydrolase Inhibitors ; Plant Exudates ; chemistry ; pharmacology

Neokotalanol, a potent α-glucosidase inhibitor isolated from Salacia reticulata, was synthesized through a key coupling reaction between a perbenzylated thiosugar and an appropriately protected perseitol triflate derived from D-mannose. This key step was found to be quite temperature dependent, and a simultaneous cyclization of the triflate leading to a characteristic 2,4,7-trioxabicyclo[4.2.1]nonane system was detected.
Enzyme Inhibitors ; chemical synthesis ; chemistry ; Glycoside Hydrolase Inhibitors ; Plant Extracts ; chemical synthesis ; chemistry ; Salacia ; chemistry

This study employed the α-glucosidase inhibitory activity model as an anti-diabetic assay and implemented a bioactivity-guided isolation strategy to identify novel natural compounds with potential therapeutic properties. Hypericum sampsoniiwas investigated, leading to the isolation of two highly modified seco-polycyclic polyprenylated acylphloroglucinols (PPAPs) (1 and 2), eight phenolic derivatives (3-10), and four terpene derivatives (11-14). The structures of compounds 1 and 2, featuring an unprecedented octahydro-2H-chromen-2-one ring system, were fully characterized using extensive spectroscopic data and quantum chemistry calculations. Six compounds (1, 5-7, 9, and 14) exhibited potential inhibitory effects against α-glucosidase, with IC₅₀ values ranging from 0.050 ± 0.0016 to 366.70 ± 11.08 μg·mL^-1. Notably, compound 5 (0.050 ± 0.0016 μg·mL^-1) was identified as the most potential α-glucosidase inhibitor, with an inhibitory effect about 6900 times stronger than the positive control, acarbose (IC₅₀ = 346.63 ± 15.65 μg·mL^-1). A docking study was conducted to predict molecular interactions between two compounds (1 and 5) and α-glucosidase, and the hypothetical biosynthetic pathways of the two unprecedented seco-PPAPs were proposed.
Molecular Structure ; Hypericum/chemistry* ; alpha-Glucosidases ; Magnetic Resonance Spectroscopy ; Glycoside Hydrolase Inhibitors/pharmacology*

OBJECTIVETo search alpha-glucosidase inhibitors from Rubia cordifolia.

METHODThe alpha-glucosidase inhibitors were isolated by the column chromatographic techniques and the bioassay-guided method in vitro. A combination of MS and NMR spectroscopy was used to identify the chemical structures. The inhibitory kinetics of the inhibitors were also investigated.

RESULTThe chloroform extract showed high inhibitory activity, and three active compounds were isolated and identified as 1,3-dihydroxy-2-methylanthraquinone (1), 1-hydroxy-2-methylanthraquinone (2) and 1,2-dihydroxyanthraquinone (3). The IC5o values of compound 1-3 were all lower than that of acarbose. Compound 1 and 2 shown competitive type manner on alpha-glucosidase, whereas compound 3 shown noncompetitive type model.

CONCLUSIONCompounds 1-3 as strong inhibitors of alpha-glucosidase were reported for the first time.

Binding, Competitive ; Enzyme Inhibitors ; analysis ; metabolism ; pharmacology ; Glycoside Hydrolase Inhibitors ; Inhibitory Concentration 50 ; Kinetics ; Rubia ; chemistry ; alpha-Glucosidases ; metabolism

Six compounds were isolated from the aerial part of cultivated Clerodendranthus spicatus in Hainan with various chromatographic techniques,and their structures were determined as:1-dehydroxy-1-oxo-rupestrinol(1),N-trans-feruloyltyramine(2),methyl 3,4-dihydroxyphenyllactate(3),caffein acid(4),methyl caffeate(5) and ethyl caffeate(6),via analysis of physicochemical properties and spectroscopic evidence.Compound 1 was a new compound,while compounds 2 and 3 were isolated from C.spicatus for the first time.Biological activity results showed that compounds 2-4 exhibited α-glucosidase inhibitory activity with different inhibition ratio.
China ; Glycoside Hydrolase Inhibitors ; isolation & purification ; pharmacology ; Lamiaceae ; chemistry ; Molecular Structure ; Phytochemicals ; isolation & purification ; pharmacology ; Sesquiterpenes, Eudesmane ; isolation & purification ; pharmacology

Chemical constituents were isolated from the fruiting bodies of Ganoderma australe by various column chromatographic techniques and HPLC method, and their chemical structures were identified through the combined analysis of physicochemical properties and spectral data. Meanwhile, their α-glucosidase inhibitory activity and anti-oxidative ability were evaluated. Seven compounds were isolated from G. australe and were identified as 6-methoxyl-cyclo-(Phe-Ile)(1), applanoxidic acid A methyl ester(2), ergosta-7,22 E-dien-3β-ol(3), cinnamic acid(4), 5α,8α-epidioxy-(20S,22E,24R)-ergosta-6,22-diene-3β-ol(5), 1-(3, 4-dihydroxyphenyl) ethanone(6), salicylic acid(7) and benzoic acid(8). Among the compounds, compound 1 was a new cyclic dipeptide. Compound 2 was a new lanosta natural product, and compounds 4, 6, 7 and 8 were obtained from G. australe for the first time. Moreover, compounds 4 and 8 exhibited α-glucosidase inhibitory activity with inhibition rates of 36.8% and 34.7%, and compounds 4, 7 and 8 had a certain activity in DPPH free radical scavenging activity with IC_(50) values of 0.168, 0.458 and 0.170 g·L~(-1), respectively. The DPPH radical scavenging rate of compound 1 was 41.1%.
Free Radical Scavengers ; isolation & purification ; Fruiting Bodies, Fungal ; chemistry ; Ganoderma ; chemistry ; Glycoside Hydrolase Inhibitors ; isolation & purification ; Molecular Structure

Diabetes is a common metabolic disorder characterized by abnormally increased plasma glucose levels. Postprandial hyperglycemia plays an essential role in development of type-2 diabetes. Inhibitors of carbohydrate-hydrolyzing enzymes (such as α-glucosidase and α-amylase) offer an effective strategy to regulate/prevent hyperglycemia by controlling starch breakdown. Natural α-amylase and α-glucosidase inhibitors, as well as antioxidants from plant-based sources, offer a source of dietary ingredients that affect human physiological function in order to treat diabetes. Several research studies have investigated the effectiveness of plant-based inhibitors of α-amylase and α-glucosidase, as well as their antioxidant activity. The aim of this review is to summarize the antidiabetic and antioxidant properties of several medicinal plants around the world. Half inhibitory concentration (IC50, for enzyme suppression) and half effective concentration (EC50, for antioxidant activity) values of less than 500 μg/mL were defined as the most potent plant-based inhibitors (in vitro) and are expected to provide interesting candidates for herbal treatment of diabetes, as foods, supplements, or refined drugs.
Antioxidants ; pharmacology ; Glycoside Hydrolase Inhibitors ; pharmacology ; Humans ; Hypoglycemic Agents ; pharmacology ; Plant Extracts ; pharmacology ; Plants, Medicinal ; alpha-Amylases ; antagonists & inhibitors