scholarly journals α-Glucosidase Inhibitors: Diphenyl Ethers and Phenolic Bisabolane Sesquiterpenoids from the Mangrove Endophytic Fungus Aspergillus flavus QQSG-3

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 307 ◽  
Author(s):  
Yingnan Wu ◽  
Yan Chen ◽  
Xishan Huang ◽  
Yahong Pan ◽  
Zhaoming Liu ◽  
...  

Two new diphenyl ethers (1 and 2) and four new phenolic bisabolane sesquiterpenoids (3–6), together with five known related derivatives, were isolated from the culture of the endophytic fungus Aspergillus flavus QQSG-3 obtained from a fresh branch of Kandelia obobata, which was collected from Huizhou city in the province of Guangdong, China. The structures of compounds 1–6 were determined by analyzing NMR and HRESIMS data. The absolute configurations of 5 and 6 were assigned by comparing their experimental ECD spectra with those reported for similar compounds in the literature. All isolates were evaluated for their α-glucosidase inhibitory activity, of which compounds 3, 5, 10, and 11 showed strong inhibitory effects with IC50 values in the range of 1.5–4.5 μM.

Marine Drugs ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 5
Author(s):  
Xiaoya Qin ◽  
Jiguo Huang ◽  
Dexiong Zhou ◽  
Wenxiu Zhang ◽  
Yanjun Zhang ◽  
...  

Four undescribed compounds, guhypoxylonols A (1), B (2), C (3), and D (4), were isolated from the mangrove endophytic fungus Aspergillus sp. GXNU-Y45, together with seven previously reported metabolites. The structures of 1–4 were elucidated based on analysis of HRESIMS and NMR spectroscopic data. The absolute configurations of the stereogenic carbons in 1–3 were established through a combination of spectroscopic data and electronic circular dichroism (ECD). Compounds 1–11 were evaluated for their anti-inflammatory activity. Compounds 1, 3, 4, and 6 showed an inhibitory activity against the production of nitric oxide (NO), with the IC50 values of 14.42 ± 0.11, 18.03 ± 0.14, 16.66 ± 0.21, and 21.05 ± 0.13 μM, respectively.


2018 ◽  
Vol 20 (1) ◽  
pp. 1-7
Author(s):  
Anastasia Wheni Indrianingsih ◽  
Amalia Indah Prihantini ◽  
Sanro Tachibana

AbstractEndophytic fungi are the microorganisms that spend all or part of their life cycles within plant tissue without causing harmful effects on the plant. In this study, 14 endophytic fungus from Quercus phillyraeoides A. Gray were isolated. Alternaria sp. QPS 05, an endophytic fungi which was isolated from the stem of Q. phillyraeoides A. Gray showed the highest α-glucosidase inhibitory activity. Further separation of ethyl acetate extract from the fungus led to the isolation of active substance from hexane-soluble fraction which give fatty acids mixture consist of palmitic acid, oleic acid, linoleic acid and linolenic acid (1) strong inhibitory activity against α-glucosidase. Isolated fatty acids (1) had inhibitory concentration (IC50) values against Saccharomyces cerevisiae was 12.10 μg/mL. The results of the present study showed that endophytic fungus from Alternaria sp. QPS 05 potentially contained a rich source of natural antidiabetic medicine.


2015 ◽  
Vol 10 (10) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Xianfu Wu ◽  
Yadan Wang ◽  
Shuchun Liu ◽  
Xinzhong Liu ◽  
Liangdong Guo

Three new ambuic acid derivatives, microsporols A-C (1-3) and the known compound ambuic acid (4), were isolated from the solid-substrate fermentation cultures of the plant endophytic fungus Pestalotiopsis microspora. Their structures were elucidated primarily by NMR experiments. The absolute configurations of the 6,7-diol moiety in 1 and 2 were assigned using the Snatzke's method, whereas that of 3 was deduced by circular dichroism (CD) exciton chirality method. Compounds 1, 3, and 4 showed moderate 5-lipoxygenase (5-LOX) inhibitory effects.


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.


Planta Medica ◽  
2021 ◽  
Author(s):  
Xiao Xia ◽  
Jiao Zhang ◽  
Xiao-Jiang Wang ◽  
Yan Lu ◽  
Dao-Feng Chen

AbstractThree new phenolic glycosides, carvacrol-2-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (1), 1-methyl-3-isopropylphenol-4-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (2), p-methoxythymol-5-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (3), and a pair of new 8-O-4′ neolignan enantiomers (5a/5b), together with 26 known compounds (4, 6 – 30) were isolated from the roots of Lilium dauricum. The structures of the new compounds were elucidated based on extensive spectroscopic and chemical methods, and the absolute configurations of 5a and 5b were established by electronic circular dichroism analysis. Nine compounds (1, 3, 4, 8, 9, 17, 25, 29, and 30) exhibited potent α-glucosidase inhibitory activity with IC50 values ranging from 73.4 µM to 988.2 µM. Besides, compound 19 displayed strong anticomplementary activity (CH50: 71.6 µM).


Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 56
Author(s):  
Yan Chen ◽  
Ge Zou ◽  
Wencong Yang ◽  
Yingying Zhao ◽  
Qi Tan ◽  
...  

One new diterpenoid, diaporpenoid A (1), two new sesquiterpenoids, diaporpenoids B–C (2,3) and three new α-pyrone derivatives, diaporpyrones A–C (4–6) were isolated from an MeOH extract obtained from cultures of the mangrove endophytic fungus Diaporthe sp. QYM12. Their structures were elucidated by extensive analysis of spectroscopic data. The absolute configurations were determined by electronic circular dichroism (ECD) calculations and a comparison of the specific rotation. Compound 1 had an unusual 5/10/5-fused tricyclic ring system. Compounds 1 and 4 showed potent anti-inflammatory activities by inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced RAW264.7 cells with IC50 values of 21.5 and 12.5 μM, respectively.


2015 ◽  
Vol 40 (3) ◽  
Author(s):  
Ali Zeytünlüoğlu ◽  
Figen Zihnioğlu

AbstractObjective: Dipeptidyl peptidase IV (DPP IV) is a serine amino (exo) peptidase which regulates various processes most notably plasma glucose homeostasis by cleaving incretin peptide hormones as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulin releasing polypeptide (GIP). Realization of the inhibition of this enzyme in controlling diabetes is one of the strategies adopted in recent years. The present study was designed to investigate the DPP IV inhibitory effects of sixteen plant having antidiabetic property in aqueous extracts in correlation with their protein content.Methods: In vitro DPP IV inhibition was evaluated by the specific inhibitory activity of plant aqueous extracts prepared without and with heat (60°C) treatment.Results: Among the tested plants Vitis vinifera L., Artemisia dracunculus L., Prunus laurocerasus L., Rubus caesius L. and Olea europaea L. extracts showed DPP IV inhibitory activity with respect to IC50 values of 0.04-0.09 mg protein/ml. Kinetic analysis indicated that the inhibitor potency of A. dracunculus extract was stronger than the other extracts.Conclusion: The present study is the first report on screening and preliminary characterization of DPP IV inhibitory activity in aqueous extracts of selected antidiabetic medicinal food. This study could provide a new insight into DPP IV inhibitors from plants that could be useful for treatment of Type 2 diabetes.


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.


Planta Medica ◽  
2014 ◽  
Vol 80 (11) ◽  
pp. 912-917 ◽  
Author(s):  
Yayue Liu ◽  
Guoping Xia ◽  
Hanxiang Li ◽  
Lin Ma ◽  
Bo Ding ◽  
...  

2018 ◽  
Vol 11 (13) ◽  
pp. 217
Author(s):  
Ratna Djamil ◽  
Yeni Eka Putri

  Objectives: The objective of this study is to investigate quality of extract, toxicity test, antioxidant activity, and test the α-glucosidase enzyme inhibitory effects of extract of bungur (Lagerstroemia speciosa L. Pers.) leaves.Methods: Extraction of leaves was conducted with maceration using 70% ethanol as solvent, followed by extract quality determination that involved extract-specific parameters. The toxicity test was performed by brine shrimp lethality test (BSLT) method, antioxidant activity by 1,1-diphenyl-2- picrylhydrazyl method, and the researchers used in vitro assay for α-glucosidase enzyme inhibitory effects.Results: Organoleptic result of the extract showed that the extract has a thick consistency, greenish-brown color, spicy taste and has not a specific aromatic odor. Phytochemical screening result indicates the presence of the simplicia ethanol extract from bungur leaves containing flavonoids, saponins, tannins, steroids, and triterpenoids. The water-soluble content 44.10%, ethanol-soluble content 60.00%, loss on drying 9.35%, water content 7.30%, total ash content 7.71%, acid-insoluble ash content 0.64%, water-soluble ash content 6.22%, ethanol residual content 0.24%, Pb and Cd metals contaminant 0.36 mg/kg and 0.10 mg/kg, microbial contamination of total plate number showed 4.32×102 colony/g, molds and yeasts number ≤1×103 colony/g, BSLT toxicity test with IC50 values of 109.4 μg/mL, antioxidant activity with IC50 values of 26.5 μg/mL and had α-glucosidase enzyme inhibitory effects, with IC50 values of 78.6 μg/mL.Conclusion: The standardized extract of bungur (L. speciosa L. Pers.) leaves are toxic, have antioxidant activity, and have α-glucosidase enzyme inhibitory activity.


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