m--The bark and hardwood of Casstifir~&~ contain tistwacidin, an optically inactive kuce anthocyanidin. 3.4.7.8.4'~pcntahydroxyflavan (I) along with barbaloin (II) and rhein (IJI). SEVERAL of the species of Cassia (Lcguminosae) occur in India and are used extensively for medicinal purposes. *A Extraction of the stem bark of C.ji~rulu first with petroleum ether removed noncrystallizable gums and resins and subsequent extraction with acetone gave one crystalline component (I). The hardwood, on extraction with petrol removed the resins and subsequent extraction with benzene gave a yellow substance (II) and final extraction with alcohol gave three products. (I, II and III). Product I melted at 245-247"d.. optically inactive and analysed for qbHI,O,. It readily gave a pcntaacetate (IV), a trimethyl ether (V) and a trimethyldiacetate (VI) indicative of three phenolic and two alcoholic hydroxyl groups. Oxidation of the trimethyl ether (V) with potassium pcrmanganate gave anisic acid and 2-hydroxy-3.4 dimethoxybcnzoic acid identified as their methyl esters. Periodate oxidation of the trimethyl ether (V) was rapid and complete during 40 min which clearly showed the existancc and the nature of hydroxyl groups as present on the same side of the C-C link which facilitate rapid oxidation with periodate. It gave the colour reactions of a typical flavandiol which prompted us to assign the structure as 3.4.7.8.4'~pcnta-hydroxytIavan (1).
Compound I shows no detectable optical rotation and must, therefore, be an isomer of (--)-terracacidin isolated by Clark-Lewisa While terracacidin is described as a brown powder, and lacvorotatory, product I is optically inactive, and crystalline melting at 245-247"d. This new product I has been designated by us as "fistucacidin". a name derived from C.@rufu. As no derivative of fistucacidin shows optical activity, it may be a racemate.
Product II is lemon yellow in colour. m.p. 146-148" and analyscd for G,H,O,. It formed a colourlcss heptaacetate' (VII) and a heptamethyl ether (VIII) and by reaction with sodium borate and phenylhydrazine hydrochloride, II was converted to emodinanthronc,6 identical with an authentical sample.
Product III is yellow in colour, m.p. 31&313". molecular formula C,H,O, and readily soluble with effervescence in sodium bicarbonate indicative of a carboxyl group. It gave a diacetate (IX) and a methyl ester (X) with CXO~SS diazomethane. The methyl ester, in turn, gave its diacctate (XI) which indicated the existance of one