Gentianaceae, xanthones

Key Word Index—Gentianaceae Xanthone glycosides Hepatitis Cholecystitis Tibetan... 

The following example comes from the work of Gottlieb and Kubitzki (1983) on the use of xanthones as indicators of relationships within Gentianaceae, a family... 

Fig. 5.1 Compounds 389 and 390 xanthones from Gentianaceae showing their formation and a graph of oxidation indices...

Swertifrancheside (= 1,5,8-Trihydroxy-3-methoxy-7-(5, 7, 3",4"-tetrahydroxy-6 -C-p-D-glucopyranosyl-4 - oxy-8 -flavyl )-xanthone) (flavone-xanthone C-glycoside) Swertia franchetiana (Gentianaceae) HIV-1 RT (43) (DNA)... 

There are two apparently unrelated centres of xanthone production in the Angiospermae the Clusiaceae and the Gentianaceae. With respect to the former, the occurrence of xanthones in such genera as Bonnetia and Archytaea has been cited as powerful evidence for allying them to the Clusiaceae rather than the Theaceae (Kubitzki et al, 1978). 

The whole plant of Swertia japonica Makino (Gentianaceae) is an important bitter stomachic in Japan where it is called "senburi". The plant is also claimed to be effective in the treatment of hepatitis (57). Components of this plant such as the bitter secoiridoids (58-63), phenyl glucosides (64), flavonoids (65) and xanthones (66-68) have been intensively studied mainly by Japanese researchers but, to date, there are few reports on the production of these constituents in vitro. Callus culture produced no bitter principles (secoiridoids) (69, 70), xanthones and flavones but coumarin derivatives, scopoletin and its glucoside were detected (71). 

Swerchirin Swertia chirayita Karst/ Gentianaceae Whole plant A xanthone was isolated from the hexane fraction of the Swertia chirayita and identified as l.8,-dihydroxy-3,5-dimethoxy xanthone (swerchirin). It has a very significant blood sugar lowering effect in fasted, fed, glucose loaded and tolbutamide pretreated albino rat models [113]. 

The LC/UV/MS analysis of Gentianaceae extracts gives useful structural information on-line for a partial identification of their metabolites. Indeed Gentianaceae plants contains UV active polyphenolic constituents such as xanthones and flavone... 

Pyrones in Lauraceae, xanthones in Gentianaceae. The variation of secondary plant constituents in major plant taxa takes place in small steps which allow to trace plant evolution and at the same time also refiect the dispersion of these taxa (11). 

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