scholarly journals Five New Pregnane Glycosides from Gymnema sylvestre and Their α-Glucosidase and α-Amylase Inhibitory Activities

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2525 ◽  
Author(s):  
Phan Van Kiem ◽  
Duong Thi Hai Yen ◽  
Nguyen Van Hung ◽  
Nguyen Xuan Nhiem ◽  
Bui Huu Tai ◽  
...  

Gymnema sylvestre, a medicinal plant, has been used in Indian ayurvedic traditional medicine for the treatment of diabetes. Phytochemical investigation of Gymnema sylvestre led to the isolation of five new pregnane glycosides, gymsylosides A–E (1–5) and four known oleanane saponins, 3β-O-β-D-glucopyranosyl (1→6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester (6), gymnemoside-W1 (7), 3β-O-β-D-xylopyranosyl-(1→6)-β-D- glucopyranosyl-(1→6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester (8), and alternoside XIX (9). Their structures were identified based on spectroscopic evidence and comparison with those reported in the literature. All compounds were evaluated for their α-glucosidase and α-amylase inhibitory activities. Compounds 2–4 showed significant α-amylase inhibitory activity, with IC50 values ranging from 113.0 to 176.2 µM.

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Mahamad Abba Talba ◽  
David Miaffo ◽  
Sylviane Laure Poualeu Kamani ◽  
Albert Kamanyi ◽  
Sylvie Léa Wansi

Cissus polyantha (Vitaceae) is a plant used in Cameroonian traditional medicine for the treatment of diabetes. The aims of this study were to evaluate the in vitro antioxidant and antidiabetic activities of the aqueous extract of Cissus polyantha leafy stems. The enzyme inhibitory activity was determined in vitro on α-amylase and α-glucosidase enzymes, followed by confirmative study in vivo on normal rats (oral starch and sucrose tolerance tests at doses of 111, 222, and 444 mg/kg). The ferric reducing antioxidant power and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) antiradical activity of the extract were examined to evaluate the antioxidant potential of the extract. The total content of phenols, flavonoids, and tannins of the extract were also determined. The results showed an inhibitory effect of the extract on the α-amylase and α-glucosidase activities with IC50 values of 216.14 and 182.40 μg/mL, respectively. The extract at doses of 222 and 444 mg/kg induced a significant decrease in postprandial glycaemia during the starch and sucrose tolerance tests. A remarkable antiradical activity of the extract was obtained although lower than that of the standard product. The aqueous extract of leafy stems of Cissus polyantha has an interesting inhibitory activity on the α-amylase and α-glucosidase enzymes, as well as an antioxidant potential, thus validating its use in traditional medicine for the treatment of diabetes mellitus and its complications.


Author(s):  
Arzumand Ara ◽  
Md. Moshfekus Saleh-E-In ◽  
Md. Abul Hashem ◽  
Mesbahuddin Ahmad ◽  
Choudhury Mahmood Hasan

Abstract Background Adenanthera pavonina L. is an important medicinal plant and its barks are used in traditional medicine for treating different diseases. Therefore, a phytochemical investigation was carried out to isolate and identify secondary metabolites from its barks. Results Seven compounds namely ethyl 3,3-dimethyl-13-hydroxytridecanoate (1), stigmasta-5,22-dien-3β-ol (2), tert.butyl tridecanoate (3), 6-α-hydroxy stigmast-20(21)-en-3-one (4) of dichloromethane extract and 18-(2′, 3′-dihydroxyphenyl)nonadec-17-en-2-ol (5), 1-(N-propyl amino)-2-henecosanone (6), and stigmast–5(6), 20(21)-diene-3-one (7) were isolated from the barks of Adenanthera pavonina Linn. Of these compounds, 1, 4, 5, 6, and 7 appear new. The structures of these compounds were elucidated by spectroscopic techniques, mainly by NMR. Conclusions Five new and two known compounds have been isolated and characterized from the bark of A. pavonina. The isolated compounds could be a potential template for the synthesis and development of new lead compounds with interesting pharmacological properties. Graphical abstract


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).


Planta Medica ◽  
2020 ◽  
Vol 86 (16) ◽  
pp. 1216-1224
Author(s):  
Asshaima Paramita Devi ◽  
Thuc-Huy Duong ◽  
Solenn Ferron ◽  
Mehdi A. Beniddir ◽  
Minh-Hiep Dinh ◽  
...  

AbstractThree new depsidones, parmosidones F – G (1 – 2), and 8′-O-methylsalazinic acid (3), and 3 new diphenylethers, parmetherines A – C (4 – 6), together with 2 known congeners were isolated from the whole thalli of Parmotrema dilatatum, a foliose chlorolichen. Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data. The isolated polyphenolics were assayed for their α-glucosidase inhibitory activities. Newly reported benzylated depsidones 1 and 2 in particular inhibited α-glucosidase with IC50 values of 2.2 and 4.3 µM, respectively, and are thus more potent than the positive control, acarbose.


2019 ◽  
Vol 12 (3) ◽  
pp. 102 ◽  
Author(s):  
Niken Pujirahayu ◽  
Debu Kumar Bhattacharjya ◽  
Toshisada Suzuki ◽  
Takeshi Katayama

This study reports on the antioxidant activity and α-glucosidase inhibitory activity of five cycloartane-type triterpenes isolated from Indonesian stingless bee (Tetragonula sapiens Cockerell) propolis and their structure–activity relationships. The structure of the triterpenes was determined to include mangiferolic acid (1), Cycloartenol (2), ambonic acid (3), mangiferonic acid (4), and ambolic acid (5). The inhibitory test results of all isolated triterpenes against α-glucosidase showed a high potential for inhibitory activity with an IC50 range between 2.46 and 10.72 µM. Among the compounds tested, mangiferonic acid (4) was the strongest α-glucosidase inhibitor with IC50 2.46 µM compared to the standard (–)-epicatechin (1991.1 µM), and also had antioxidant activities with IC50 values of 37.74 ± 6.55 µM. The study on the structure–activity relationships among the compounds showed that the ketone group at C-3 and the double bonds at C-24 and C-25 are needed to increase the α-glucosidase inhibitory activity. The carboxylic group at C-26 is also more important for increasing the inhibitory activity compared with the methyl group. This study provides an approach to help consider the structural requirements of cycloartane-type triterpenes from propolis as α-glucosidase inhibitors. An understanding of these requirements is deemed necessary to find a new type of α-glucosidase inhibitor from the cycloartane-type triterpenes or to improve those inhibitors that are known to help in the treatment of diabetes.


2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Nurul Iman Aminudin ◽  
Farediah Ahmad ◽  
Muhammad Taher ◽  
Razauden Mohamed Zulkifli

A phytochemical investigation of the crude extracts of the bark and leaves of Calophyllum symingtonianum has resulted in the isolation of inophyllum D, inophyllum H, calanone, isocordato-oblongic acid, amentoflavone, carpachromene and lupenone. Their chemical structures were elucidated and confirmed by spectroscopic analysis. All flavonoids and coumarins showed significant α-glucosidase inhibitory activity, while amentoflavone gave a positive result against 15-lipoxygenase inhibition.


MedPharmRes ◽  
2017 ◽  
Vol 1 (1) ◽  
pp. 15-25
Author(s):  
Dao Tran ◽  
Son Tran ◽  
Vi Nguyen ◽  
Tri Le ◽  
Minh Thai ◽  
...  

In this study, a total of twenty chalcones were synthesized via Claisen-Schmidt condensation reaction and evaluated for their in vitro acetylcholinesterase inhibitory activities using Ellman’s method. Molecular docking studies on acetylcholinesterase were performed to elucidate the interactions between these chalcone derivatives and acetylcholinesterase active site at the molecular level. From the series, six compounds (S1-5 and S17) exhibited strong acetylcholinesterase inhibitory activities with IC50 values below 100 µM compared to the parent unsubstituted chalcone. Compound S17 (4’-amino-2-chlorochalcone) showed the strongest acetylcholinesterase inhibitory activity in the investigated group with IC50 value of 36.10 µM. Molecular modeling studies were consistent with the results of in vitro acetylcholinesterase inhibitory activities, and chalcone S17 could be considered as a potential lead compound for the development of new acetylcholinesterase inhibitors.


2020 ◽  
Vol 10 (1) ◽  
pp. 26-32
Author(s):  
Phuong T.M. Nguyen ◽  
Quang V. Ngo ◽  
Minh T.H. Nguyen ◽  
Alan T. Maccarone ◽  
Stephen G. Pyne

Background: A therapeutic approach to treat diabetes is to decrease postprandial hyperglycemia. α-Glucosidase inhibitors from plant sources offer an attractive strategy for the control of hyperglycemia. Smilax glabra Roxb is a medicinal plant found in Asia, including Vietnam, which is used in the treatment of chronic diseases. However, the antidiabetic activity and the identification of α-glucosidase inhibitors from this plant have not been intensively investigated. This research was carried out to determine the α-glucosidase inhibitory activity of the extracts and that of the major phytochemical components of Smilax glabra Roxb. This could lead to further studies on the role of these compounds in hyperglycemia control, as well as identify their potential future applications. Methods: Column chromatography combined with crystallization procedures were used to isolate active fractions and two major compounds. The chemical structures of these compounds were determined by analysis of their NMR spectroscopic data, as well as MS data and comparisons made with the literature data. The α-glucosidase inhibitory activity was determined spectrophotometrically using p-nitrophenyl α-D-glucopyranoside as a substrate. The in vitro cytotoxicity of the isolated compounds and fractions was determined using the MTT assay. Results: The two major compounds, astilbin and 5-O-caffeoylshikimic acid together with two very active fractions, F7 and F8, were isolated from the rhizome. The two major compounds had α- glucosidase inhibitory activities with IC50 values of ca. 125 µg/mL and 38 µg/mL, respectively which are about 4 and 13 folds higher activity than the reference compound acarbose (IC50 of ca. 525 µg/mL). Fractions F7 and F8 showed very promising inhibitory activities towards α-glucosidase with IC50 values of 5.5 and 5.8 µg/mL, respectively. Cytotoxicity data on mouse fibroblast NIH3T3 cells indicated that the active compounds and fractions were not toxic at concentrations that are greater than their respective IC50 values. The α-glucosidase inhibitory activity of 5-Ocaffeoylshikimic acid and that of the two active fractions are reported here for the first time. Conclusion: The two major isolated compounds and fractions, F7 and F8, significantly contribute to the α-glucosidase inhibitory activity of S. glabra Roxb extract. Further work is needed to clarify their modes of action and potential application.


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