[Chemical constituents in Thunbergia from Africa].
OBJECTIVE
To investigate the chemical compounds from the ethanol extract with inhibitory effects against aldose reductase from Thunbergia.


METHODS
Guided by anti-aldose reductase assay, compounds from the bioactive fraction (ethyl acetate extract) were separated and purified by various chromatographic methods including silica gel, Sephadex LH-20, and reversed-phase HPLC. Their structures were indentified based on analysis of the spectroscopic data including 1D and 2D NMR data.


RESULTS
Eight compounds were obtained and identified as 8-hydroxy-8-methyl-9-methene-cyclopentane [7,11] -1,4, 6-trihydroxy-tetrahydronaphthalene-12-one, named as thunbergia A (1), 3,4-dihydro-4,5,8-trihydroxy-2-(3-methyl-2-butenyl) naphtha[2,3-b] oxiren-1(2H)-one (2), 8-(beta-gluco pyranosyloxy)-3,4-dihydro-2-(3-methyl-2-butenyl)naphtha [2,3-b] oxiren-1(2H)-one (3), galangin (4), quercetin (5), luteolin (6), 5,6,3',4'-tetrahydroxy -3,7-dimethoxy-flavone (7) and upeol (8).


CONCLUSIONS
Thunbergia A was a new derivative of tetrahydronaphthalene, and compounds 2 and 3 were separated from the genus Thunbergia for the first time.
School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China.
Feng-Jie
FJ
Hung
Jian-Xiao
JX
Song
Jia-Jian
JJ
Liu
Ai-Hu
AH
Zhao
Wei
W
Jia
D027901:Acanthaceae / Q000737:chemistry*; D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors; D000818:Animals; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D051381:Rats
D010936:Plant Extracts; D000449:Aldehyde Reductase