Quinovic acid glycosides

Quinovic acid glycosides from U. tomentosa e U. guaianensis... 

An in vitro study examined the ability of six components of a a cat s claw bark extract to inhibit two RNA viruses, vesicular stomatitis virus (VSV) and rhinovirus type IB (HRV IB) (Aquino et al., 1989). Three major glycosides and three other quinovic acid glycosides were studied. An inhibitory effect was evident for all six compounds at relatively high concentrations (i.e., the MIC50 approached the concentration that affected host cell morphology and growth). 

Aquino R, DeSimone F, Pizza C. Plant metabolites. Structure and in vitro antiviral activity of quinovic acid glycosides from Uncaria tomentosa and Guettarda platypoda. J Nat Prod 1989 52 679-85. 

Microbial transformations of quinovic acid glycosides (138-141) by Nocardia sp. [102] or Streptomyces griseus [103]. 

Z.-H. Cheng, B.-Y. Yu, G. A. Cordell, S.-X. Qiu, Biotransformation of quinovic acid glycosides by microbes Direct conversion of the ursane to the oleanane triterpene skeleton by Nocardia sp. NRRL 5646, Org. Lett. 2004.6,3163-B165. 

A quinovic acid glycoside (28)-p-D-glucopyranosyl-ester that was isolated from U. tomentosa exhibited antiviral activity against ihinovims type IB infection in HeLa cells. Cinchonain-Ia and cinchonain-Ib and epicatechin isolated from the bark of this plant showed significant antiviral and antiinflammatory activity [70]. 

A number of alkaloids producing a pronounced enhancement of phagocytosis were isolated by Wagner et al. (20) As a part of our continuing search for new biologically active metabolites from U. tomentosa we preceded to a bioassay-directed fractionation of the extracts from V. tomentosa. The extracts and fractions have been bioassayed by the carrageenan induced edema test on rat paw. This allowed us to identify a quinovic acid derivative with a C-3,27 glycosidation pattern, 21. as one of the active anti-inflammatory principles of U. tomentosa. (11). 

Phytochemistry The whole plant contains up to 2 % alkaloids, the main ones being zygofabagine, harmine, and others. Leaves contain 15.7-70 mg% and fruits up to 10 mg% of vitamin C (Seredin and Sokolov 1969). The baik contains trite-penoid glycosides, quinovic acid and its derivatives as well as a cinchoUc add derivative (Feng et al. 2007). 

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