Pharmacologically Active Secondary Metabolites from Wood

Ancient-modern concordance in Ayurvedic plants: some examples

Ayurveda is the ancient (before 2500 b.c.) Indian system of health care and longevity. It involves a holistic view of man, his health, and illness. Ayurvedic treatment of a disease consists of salubrious use of drugs, diets, and certain practices. Medicinal preparations are invariably complex mixtures, based mostly on plant products. Around 1,250 plants are currently used in various Ayurvedic preparations. Many Indian medicinal plants have come under scientific scrutiny since the middle of the nineteenth century, although in a sporadic fashion. The first significant contribution from Ayurvedic materia medica came with the isolation of the hypertensive alkaloid from the sarpagandha plant (Rouwolfia serpentina), valued in Ayurveda for the treatment of hypertension, insomnia, and insanity. This was the first important ancient-modern concordance in Ayurvedic plants. With the gradual coming of age of chemistry and biology, disciplines central to the study of biologic activities of natural products, many Ayurvedic plants have been reinvestigated. Our work on Commiphora wightti gum-resin, valued in Ayurveda for correcting lipid disorders, has been described in some detail; based on these investigations, a modern antihyperlipoproteinemic drug is on the market in India and some other countries. There has also been concordance for a few other Ayurvedic crude drugs such as Asparagus racemosus, Cedrus deodara, and Psoralea corylifolia.

Antimutagenicity of hydrolyzable tannins from Terminalia chebula in Salmonella typhimurium

A tannin fraction (TC-E) from the dried fruit pulp of Terminalia chebula was obtained by successfully extracting with 95% ethyl alcohol and ethyl acetate. TC-E was subjected to silica gel chromatography which yielded four fractions, viz., TC-EI, TC-EII, TC-EIII and TC-EIV. Thin layer chromatography (TLC) and 13C-NMR revealed that TC-EI was gallic acid (GA) derivative while the other fractions were tannin in nature. TC-E and its fractions were evaluated for their antimutagenic potential against two direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and 4-nitroquinoline-N-oxide (4NQNO), and S9-dependent mutagen, 2-aminofluorene (2AF) in TA98 and TA100 strains of Salmonella typhimurium. The study revealed that the extract (TC-E) and its fractions were highly significant against S9-dependent mutagen, 2AF. The effect was found to be more or less corresponding with the nature of the fractions, as the monomeric TC-EI (a GA derivative) was least effective as compared to other fractions which were oligomeric, and the order of their effectiveness as per their IbD50 value being TC-EIV (8.9 micrograms)>TC-EIII (17.8 micrograms)>TC-EII (45 micrograms)>TC-EI (320 micrograms) in TA98; TC-EIV being 40 times more effective than TC-EI in inhibiting his+ revertants. A similar effect was noticed in TA100 too, where TC-EI was the least effective and TC-EII had the maximum effect. A similar result was noticed when the antimutagenicity of GA (a monomeric) was compared with tannic acid (TA, an oligomeric). However, chebula tannins were found to be partly effective against NPD but not at all effective against 4NQNO.

Phenolic Compounds from Cyclopia intermedia (Honeybush Tea). 1

The processed leaves and stems of Cyclopia intermedia contain 4-hydroxycinnamic acid, the isoflavones formononetin, afrormosin, calycosin, pseudobaptigen, and fujikinetin, the flavanones naringenin, eriodictyol, hesperitin, and hesperidin, the coumestans medicagol, flemichapparin, and sophoracoumestan B, the xanthones mangiferin and isomangiferin, the flavone luteolin, and the inositol (+)-pinitol.