Swietemicrolides A-D, mexicanolide-type limonoids from the bark of with cytotoxic and α-glucosidase inhibitory activities.

Four new mexicanolide-type limonoids, swietemicrolides A-D (1-4), together with three known compounds (5-7) were isolated from an ethyl acetate extract of the bark of . 1 and 2 had 1,8-hemiacetal systems whilst 3 and 4 shared hexacyclic skeletons consisting of three fused five-membered rings. The structures of the isolated compounds were determined using spectroscopic methods.

In vitro and in silico antioxidant and α-glucosidase inhibitory potential of compounds isolated from .

Nine compounds including a new one, garcichaudiic acid (), were isolated from the bark of and their structures were characterized mainly by 1 D and 2 D NMR experiments. The antioxidant capacity of the isolated compounds was determined using DPPH radical scavenging assay and the anti-hyperglycemic activity was assessed by measuring the inhibitory effect against α-glucosidase. Among them, compound showed higher antioxidant activity than the positive control, ascorbic acid, while both compounds and exhibited more significant α-glucosidase inhibitory activity than the reference drug acarbose.

Two new antidiabetic xanthones from the twigs of .

Two new xanthones, oblongixanthones I () and J (), and seven known compounds (-), were isolated from an EtOAc extract of the twigs of . Their structures were elucidated using spectroscopic methods, mainly 1 D and 2 D NMR. The antidiabetic effects of the two new compounds were evaluated using α-glucosidase and PTP1B inhibition assays.

Triterpenoids from the bark of .

Two new triterpenoids, entanolide () and methyl 3,4-secotirucalla-23-oxo-4(28),7,24-trien-21-al-3-oate (), together with nine known compounds (), were isolated from the bark of . Their structures were elucidated based on spectroscopic analyses, mainly 1 D and 2 D NMR spectral data. Compounds - and were evaluated for their cytotoxicity against HepG2 cells, and compounds exhibited weak activities.

Antioxidant and Antimicrobial Activities of the Extracts from Different Species.

Background: is a large genus which has promising bioactivities. However, the properties of many species have not been investigated thoroughly.

Aim: To determine the antioxidant and antimicrobial capabilities of the extracts from different species.

Chemical constituents of and and their cytotoxicity.

Two new rocaglamides, 8b--5-oxohexylrocaglaol () and elaeagnin (), together with twelve known compounds, were isolated from the bark of and the whole tree of . Their structures were determined using spectroscopic methods, mainly 1D and 2D NMR. Cytotoxic activity against HepG2 human liver cancer cells of the isolated compounds was evaluated using the SRB assay.

Cytotoxic limonoids from the bark of Walsura cochinchinensis.

Three new limonoids, walsucochinones A-C (1-3), along with eight known compounds, were isolated from an ethyl acetate extract of the bark of Walsura cochinchinensis. Their structures were determined using spectroscopic techniques, mainly 1-D and 2-D NMR. The ethyl acetate extract showed cytotoxic activity against MCF-7 human breast cancer cells and cytotoxicity of the isolated compounds were evaluated in vitro using the SRB assay.

High-Resolution Inhibition Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of PTP1B Inhibitors from Vietnamese Plants.

Protein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator in insulin signal transduction by deactivating the insulin receptor. Thus, PTP1B inhibition has emerged as a potential therapeutic strategy for curing insulin resistance. In this study, 40 extracts from 18 different plant species were investigated for PTP1B inhibitory activity in vitro.

Anti-diabetic xanthones from the bark of Garcinia xanthochymus.

An ethyl acetate extract the bark of Garcinia xanthochymus exhibited strong inhibition towards α-glucosidase and PTP1B with IC values of 0.3±0.1μg/mL and 2.

Xanthones from the twigs of Garcinia oblongifolia and their antidiabetic activity.

Three new xanthones, oblongixanthone F-H (1-3), along with eight known xanthones (4-11), were isolated from an EtOAc extract of the twigs of Garcinia oblongifolia. Their structures were elucidated by spectroscopic analysis including 1D- and 2D-NMR spectroscopy and mass spectrometry. The antidiabetic effects of all isolated compounds were evaluated by in vitro α-glucosidase and PTP1B inhibition assays.

Screening for potential α-glucosidase and α-amylase inhibitory constituents from selected Vietnamese plants used to treat type 2 diabetes.

Ethnopharmacological Relevance: The 18 plant species investigated in this study have been used as herbal antidiabetic remedies in Vietnamese traditional medicines. This study aimed to evaluate their ability to inhibit α-glucosidase and α-amylase, two key enzymes involved in serum glucose regulation.

Materials And Methods: Chloroform, ethanol and water extracts of 18 plants were screened for α-glucosidase and α-amylase inhibitory activity.

Friedolanostane, friedocycloartane and benzophenone constituents of the bark and leaves of Garcinia benthami.

Friedolanostanes, (22Z,24E)-3β-acetoxy-9α-hydroxy-17,14-friedolanosta-14,22,24-trien-26-oic acid, (22Z,24E)-3β,9α-dihydroxy-17,14-friedolanosta-14,22,24-trien-26-oic acid, (22Z,24E)-9α-hydroxy-3-oxo-17,14-friedolanosta-14,22,24-trien-26-oic acid, a friedocycloartane, (22Z,24E)-3α-hydroxy-17,13-friedocycloarta-12,22,24-trien-26-oic acid, and a benzophenone, benthaphenone, together with known compounds (22Z,24E)-3α,9α-dihydroxy-17,13-friedolanosta-12,22,24-trien-26-oic acid, methyl (24E)-3α,23-dihydroxy-17,14-friedolanosta-8,14,24-trien-26-oate, glutinol, lupeol, and stigmasterol, were isolated from leaves and bark of Garcinia benthami. Their structures were elucidated using spectroscopic techniques, mainly 1-D and 2-D NMR spectroscopy, and chemical correlations.