Alpha-glucosidase inhibitory compounds from Vietnamese lichen : and aspects.

Using a bio-guided isolation on the Vietnamese lichen based on alpha-glucosidase inhibition, eleven compounds were isolated and structurally elucidated, namely, protocetraric acid (1), 8'-methylstictic acid (2), stictic acid (3), 4,6-diformyl-8-hydroxy-3-methoxy-1,9-dimethyl-11-oxo-11-dibenzo[,][1,4]dioxepine-7-carboxylic acid (4), vicanicin (5), norstictic acid (6), diffractaic acid (7), barbatic acid (8), atranol (9), 5-chlorohaematommic acid (10), and eumitrin A1 (11). Their chemical structures were identified by extensive 1D and 2D NMR analysis and high-resolution mass spectroscopy and compared with those reported in literature. Protocetraric acid (1) and norstictic acid (6) were selected for further modification to derive new compounds, namely, 1a-1e and 6a.

A new diphenyl ether from the cultured lichen mycobiont of cf. .

Lichen is well-known for its various purposes. However, understanding the chemical composition and antimicrobial characteristics of cf. remains insufficient.

New Halogenated Flavonoids from Adenosma bracteosum and Vitex negundo and Their α-Glucosidase Inhibition.

Adenosma bracteosum and Vitex negundo are natural sources of methoxylated flavonoids. Little is known about the α-glucosidase inhibition of multi-methoxylated flavonoid derivatives. Eighteen natural flavonoids were isolated from A.

α-Glucosidase inhibitory derivatives of protocetraric acid.

Lichen-derived depsidones have been a successful source for alpha-glucosidase inhibitory agents with numerous advantages. In this article, derivatives of protocetraric acids were designed and synthesised. Diels-Alder reaction, esterification, and Friedel-Crafts alkylation of protocetraric acid with different reagents under Lewis acid were performed.

α-Glucosidase Inhibition by Usnic Acid Derivatives.

This study investigated a set of new potential antidiabetes agents. Derivatives of usnic acid were designed and synthesized. These analogs and nineteen benzylidene analogs from a previous study were evaluated for enzyme inhibition of α-glucosidase.

Synthesis, structure and in vitro cytotoxicity testing of some 2-aroylbenzofuran-3-ols.

Five 2-aroyl-5-bromobenzo[b]furan-3-ol compounds (two of which are new) and four new 2-aroyl-5-iodobenzo[b]furan-3-ol compounds were synthesized starting from salicylic acid. The compounds were characterized by mass spectrometry and H NMR and C NMR spectroscopy. Single-crystal X-ray diffraction studies of four compounds, namely, (5-bromo-3-hydroxybenzofuran-2-yl)(4-fluorophenyl)methanone, CHBrFO, (5-bromo-3-hydroxybenzofuran-2-yl)(4-chlorophenyl)methanone, CHBrClO, (5-bromo-3-hydroxybenzofuran-2-yl)(4-bromophenyl)methanone, CHBrO, and (4-bromophenyl)(3-hydroxy-5-iodobenzofuran-2-yl)methanone, CHBrIO, were also carried out.

Design, modification of phyllanthone derivatives as anti-diabetic and cytotoxic agents.

Twelve benzylidene derivatives, one Baeyer-Villiger oxidative, six imine derivatives were successfully designed and synthesised from phyllanthone. In the search for potential new anti-diabetic agents, phyllanthone along with its benzylidene and oxidation analogues were evaluated for enzyme inhibition against -glucosidase. In the benzylidene series, most analogues displayed stronger activity than the mother compound.

Synthesis and structure of ethyl 2-[(4-oxo-3-phenyl-3,4-di-hydro-quinazolin-2-yl)sulfan-yl]acetate.

The title compound, CHNOS, was synthesized by reaction of 2-mercapto-3-phenyl-quinazolin-4(3)-one with ethyl chloro-acetate. The quinazoline ring forms a dihedral angle of 86.83 (5)° with the phenyl ring.

Design and synthesis of new lupeol derivatives and their -glucosidase inhibitory and cytotoxic activities.

A series of lupeol derivatives , , , , and were designed, synthesised and evaluated for their -glucosidase inhibitory and cytotoxic activities. Among synthetic derivatives, lupeol analogues and containing a benzylidene chain exhibited the best activity against -glucosidase and superior to the positive agent with the IC values of 29.4 ± 1.

Synthesis and cytotoxic evaluation of usnic acid benzylidene derivatives as potential anticancer agents.

A series of usnic acid benzylidene derivatives (groups ) were designed, synthesized and evaluated for their anticancer activity in the search for potentially new anticancer agents. Compounds , , , and exhibited the most potent cytotoxcity against K562 cell line with IC values of 10.0 ± 3.