scholarly journals a-GLUCOSIDASE INHIBITORY ACTIVITY AND CHEMICAL CONSTITUENTS OF Satholobus parviflorus (Roxb.)

2011 ◽  
Vol 14 (2) ◽  
pp. 43-49
Author(s):  
Mai Thi Thanh Nguyen ◽  
Trong Nguyen Huu Phan ◽  
Hai Xuan Nguyen ◽  
Nhan Trung Nguyen

Our preliminary screening study revealed that the methanolic extract of Stholobus parviflorus (Roxb.) exhibited potent a-glucosidase inhibitory activity with an IC50 value of 0.05 μg mL-1. Therefore, we carried out activity-guided fractionation of the MeOH extract and isolated three compounds. These compounds were determinated as ferulic acid (1), protocatechuic acid (2) and epicatechin (3) by analysis of spectroscopic data. The IC50 values of these compounds were 45.30, 23.04 and > 100 μM, respectively. Acid tannic was used as a positive control with an IC50 value of 0.91 nM.

2018 ◽  
Vol 17 (3) ◽  
pp. 134-139
Author(s):  
R.M. Perez-Gutierrez

Methanol extract from Lippia graveolens (Mexican oregano) was studied in order to identify inhibitory bioactives for protein tyrosine phosphatase 1B (PTP1B). Known flavone as lutein (1), and another flavone glycoside such as lutein-7-o-glucoside (2), 6-hydroxy-lutein-7-ohexoside (3) and lutein-7-o-ramnoide (4) were isolated from methanol extract of aerial parts of the Lippia graveolens. All isolates were identified based on extensive spectroscopic data analysis, including UV, IR, NMR, MS and compared with spectroscopic data previously reported. These flavones were evaluated for PTP1B inhibitory activity. Among them, compounds 1 and 3 displayed potential inhibitory activity against PTP1B with IC50 values of 7.01 ± 1.25 μg/ml and 18.4 μg/ml, respectively. In addition, compound 2 and 4 showed moderate inhibitory activity with an IC50 value of 23.8 ± 6.21 and 67.8 ± 5.80 μg/ml respectively. Among the four compounds, luteolin was found to be the most potent PTP1B inhibitor compared to the positive control ursolic acid, with an IC50 value of 8.12 ± 1.06 μg/ml. These results indicate that flavonoids constituents contained in Lippia graveolens can be considered as a natural source for the treatment of type 2 diabetes.


2021 ◽  
Vol 63 (4) ◽  
pp. 42-46
Author(s):  
Thi-My-Linh Lam ◽  
◽  
Minh-Tuan Le ◽  
Manh-Ha Bui ◽  
◽  
...  

A study on the α-glucosidase inhibitory activity of 40 kinds of vegetables, tubers, and fruits found in the An Giang province was conducted. The results indicated that all 40 extracted samples displayed α-glucosidase inhibitory activity at a concentration of 250 μg ml-1, 36 extracted samples showed an inhibition rate greater than 50% at 250 μg ml-1, 25 extracted samples had over 50% at 100 μg ml-1, 17 extracted samples possessed more than 50% at 50 μg ml-1, 7 extracted samples sampled showed over 50% at 25 μg ml-1, 5 extracted samples were greater than 50% at 10 μg ml-1, and 1 extracted sample was greater than 50% at 1 μg ml-1. Among the 40 samples, those taken from the seeds of Areca catechu, the fruits of Cassia grandis, the fruits of Syzygium cumini, the seeds of Glycine max,andthe stems of Enydra fluctuansexhibited the strongest α-glucosidase inhibitory activity in methanol, with IC50 values of 0.15, 2.54, 4.05, 5.17 and 8.68 μg ml-1, respectively, which were stronger than the positive control acarbose with an IC50 value of 214.5 μg ml-1


2021 ◽  
Vol 5 (3) ◽  
pp. 1326-1333
Author(s):  
Nhan Trung Nguyen ◽  
Truong Nhat Van Do ◽  
Tho Huu Le ◽  
Phu Hoang Dang ◽  
Hai Xuan Nguyen ◽  
...  

Solanum procumbens called ``Cà gai leo'' in Vietnam, belonged to the family of Solanaceae, which is a prickly diffuse, bright green perennial shrub, woody at the base. This plant has been sought for plenty of Vietnamese folk remedies for diseases such as rheumatism, back pain, detoxification, cough, pain relief, hemostasis, hepatitis, and cirrhosis. Chemical reports revealed the presence of lots of secondary metabolites such as steroids, triterpenoids, alkaloids, and phenolic compounds that have good biological activities such as antibacterial, antidiabetic, antioxidant, and antimicrobial... By column chromatography method together with thin layer normal-phase chromatography on the ethyl acetate extract of its entire plant, we isolated four compounds including dioscin (1), b -sitosterol (2), daucosterol (3) and 6'-O-acetyl-b -daucosterol (4). The result of theira-glucosidase inhibitory activity showed that compounds 2 and 4 had strong inhibition with IC50 values of 35.2 and 209.5 mM, comparing to the positive control, acarbose with an IC50 value of 214.5 mM. The results of this study have contributed to the scientific data of chemical compositions of Vietnamese medicinal plants, among them S. procumbens would potentially be developed as a plant-based drug to decrease the blood glucose level.


2021 ◽  
Vol 5 (3) ◽  
pp. 1334-1340
Author(s):  
Truong Nhat Van Do ◽  
Hai Xuan Nguyen ◽  
Tho Huu Le ◽  
Mai Thanh Thi Nguyen

Taxotrophis ilicifolius, called "Gai quít" in Vietnam, belonged to the family of Moraceae. The stems of T. ilicifolius are used in traditional medicine to cure pimples, anti-inflammatory, antibacterial... By column chromatography method together with thin layer chromatography on the ethyl acetate extract of its stems, six compounds were isolated including wogonin (1), 4-hydroxybenzoic acid (2), vanillic acid (3), vanillin (4), syringic acid (5), and syringaldehyde (6). Their chemical structures were elucidated by extensive NMR spectroscopic analysis and comparison with the literature data. The isolated compounds were tested fora-glucosidase inhibitory activity. All compounds showed more potent inhibitory activity with IC50 values 42–142 mM, than that of a positive control acarbose (IC50, 214.5 mM). Among all isolates, compounds 2, 4 and 6 exhibited significant a-glucosidase inhibitory activity with the IC50 values of 49.7, 42.6 and 55.9 mM, respectively. From the present investigation, all these compounds were isolated for the first time as well as their a-glucosidase inhibitoryactivity of T. ilicifolius. These results suggested that the traditional use of T. ilicifolius for the treatment of diabetes disease in Vietnam may be due to thea-glucosidase inhibitory activity of its phenolic constituents.


Author(s):  
Huu Tho Le ◽  
Truc Thanh Thi Duong ◽  
Phu Hoang Dang ◽  
Truong Nhat Van Do ◽  
Hai Xuan Nguyen ◽  
...  

Salacia chinensis L., known as “Chop mao” in Vietnam, is a climbing shrub that belongs to the Celastraceae family. The stem of S. chinensis L. is used as a traditional medicine for the treatment of diabetes, rheumatoid arthritis, back pain, … The dried powdered stem of S. chinensis L. was collected in Phu Yen province and was extracted with methanol to yield methanol extract. The methanol extract was suspended in H2O and partitioned successively with n-hexane, CHCl3, EtOAc to obtain n-hexane, CHCl3, EtOAc, and H2O fractions, respectively. The CHCl3 fraction was subjected to a series of chromatographic separation to afford four purified compounds including 3-oxolup-20(29)-en-30-al (1), betulin-3-caffeate (2), 2-(4-hydroxy-3,5-dimethoxylphenyl)ethanol (3), and acetosyringone (4). Their structures were elucidated on the basis of the spectroscopic analysis and comparison with literature data. The isolated compounds were tested for their α-glucosidase inhibitory activity. The result indicated that all compounds (1-4) possessed significant α-glucosidase at the testing concentration of 100 µM with the percent inhibition values of 9.5 ± 1.3, 70.89 ± 0.25, 44.2 ± 1.6, and 6.7 ± 1.7 %, respectively. In addition, betulin-3-caffeate (2) and 2-(4-hydroxy-3,5-dimethoxylphenyl)ethanol (3) show more potent α-glucosidase inhibitory activity, with IC50 values of 69.7 and 152.0 µM, respectively, than that of positive control acarbose (IC50 = 214.5 µM).


2021 ◽  
Vol 23 (4) ◽  
Author(s):  
Thuy Thi Le Nguyen ◽  
Tung Thanh Bui ◽  
Phung Kim Phi Nguyen ◽  
Chi Minh Tran ◽  
Tu Dang Cam Phan ◽  
...  

Introduction: Bruguiera cylindrica is one of the mangrove plants belonging to Bruguiera genus. This genus is characterized by the presence of a large number of compounds, but the research on bioactivities has not been investigated so far. In the present research, the α-glucosidase inhibitory activity, as well as chemical constituents of the ethyl acetate extract of this plant, were studied. Methods: The chemical structures of two new compounds were elucidated by spectroscopic and computational methods. Results: Two new compounds, benzobrugierol (1) and bruguierine (2), were isolated from leaves of Bruguiera cylindrica (L.) Blume, together with nine known ones, including lupeol (3), betulin (4), chrysoeriol (5), glut-5-ene-3-ol (6), cholesta-4-ene-3-one (7), 3α-(Z)-coumaroyllupeol (8), 3α-(E)-coumaroyllupeol (9), 3β-hydroxycholesta-5-ene-7-one (10) and β-sitosterol 3-O-β-D-glucopyranoside (11). Extracts and some isolated compounds were evaluated for α-glucosidase inhibitory activities. Conclusion: The results showed that most of the extracts and tested compounds exhibited activities better than the positive control acarbose, especially two new compounds 1 and 2 with their IC50 values of 17.9 ± 0.4 and 34.6 ± 0.7 (mg/mL), respectively.


2017 ◽  
Vol 25 (2) ◽  
pp. 481-487 ◽  
Author(s):  
Do Thi Thao ◽  
Le Quang Huan ◽  
Do Khac Hieu ◽  
Nguyen Quyet Chien ◽  
Nguyen Van Hung

Aromatase inhibitory and cytotoxic activities were determined for apigenin, luteolin and the new diterpene named scutebarbalactone VN, which were obtained by bioassay-guided fractionation and isolation from the methanol extract of the Vietnamese medicinal plant Banchi-lien (Scutellaria barbata D. Don). In the aromatase inhibition assay, an IC50 value of 3.36 mM was found for scutebarbalactone VN, while IC50  values of 7.2 mM and 7.95 mM were found for the positive controls aminoglutethimide and b-estradiol, respectively. In the cytotoxicity  assays using a panel of human cancer cell lines, scutebarbalactone VN showed promising anticancer activity with IC50  ranging from 2.15 to 8.3 mM compared with those of the positive control ellipticine ranging from 1.0 to 2.1 mM. Apigenin and luteolin were found to be inactive  in both assays.  


2020 ◽  
Vol 16 ◽  
Author(s):  
Wei-Wei Ni ◽  
Hai-Lian Fang ◽  
Ya-Xi Ye ◽  
Wei-Yi Li ◽  
Li Liu ◽  
...  

Background: Thiourea is a classical urease inhibitor usually as a positive control, and many N,N`-disubstituted thioureas have been determined as urease inhibitors. However, due to steric hindrance, N,N`-disubstituted thiourea motif could not bind urease as thiourea. On the contrary, N-monosubstituted thioureas with a tiny thiourea motif could theoretically bind into the active pocket as thiourea. Objective: A series of N-monosubstituted aroylthioureas were designed and synthesized for evaluation as urease inhibitors. Methods: Urease inhibition was determined by the indophenol method and IC50 values were calculated using computerized linear regression analysis of quantal log dose-probit functions. The kinetic parameters were estimated viasurface plasmon resonance (SPR) and by nonlinear regression analysis based on the mixed type inhibition model derived from Michaelis-Menten kinetics. Results: Compounds b2, b11and b19 reversibly inhibited urease with a mixed mechanism, and showed excellent potency against both cell-free urease and urease in intact cell, with IC50 values being 90-to 450-fold and 5-to 50-fold lower than the positive control acetohydroxamic acid, respectively. The most potent compound b11 showed IC50 value of 0.060 ±0.004μM against cell-free urease, which bound to urea binding site with a very low KDvalue (0.420±0.003nM) and a very long residence time (6.7 min). Compound b11was also demonstrated having very low cytotoxicity to mammalian cells. Conclusion: These results revealed that N-monosubstituted aroylthioureas clearly bind the active site of urease as expected, and represent a new class of urease inhibitors for the development of potential therapeutics against infections caused by ure-ase-containing pathogens.


Planta Medica ◽  
2021 ◽  
Author(s):  
Birgit Waltenberger ◽  
Françoise Lohézic-Le Dévéhat ◽  
Thi Huyen Vu ◽  
Olivier Delalande ◽  
Claudia Lalli ◽  
...  

AbstractProtein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1694
Author(s):  
Kamel Arraki ◽  
Perle Totoson ◽  
Alain Decendit ◽  
Andy Zedet ◽  
Justine Maroilley ◽  
...  

Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1–2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C.thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1–7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4–7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model.


Sign in / Sign up

Export Citation Format

Share Document