Bioactive triterpenes

BIOACTIVE TRITERPENES AND RELATED COMPOUNDS FROM CELASTRACEAE... 

BIOACTIVE TRITERPENE GLYCOSEDES FROM SEVERAL MEDICINAL FOODSTUFFS... 

In conclusion, 40 compounds were isolated and identified from the seeds of V. segetalis. 15 of them (2-11, 14, 17, 18, 28, 31) are new compounds, one of them (37) is a new natural product. Most of these new compounds have complex structures. New 2D techniques, HMQC-TOCSY and HMBC-TOCSY, were applied to determine their structures. 18 compounds were tested for the inhibition of Luteal cells in rats. Three new compounds showed very strong inhibition resulting in 100% at a concentration of 20 / mL. One new flavonoid showed inhibitory effect on the growth of the HL-60 cell line. Thus, the seeds of V. segetalis are a rich source of bioactive triterpene saponins, alkaloids, cyclic peptides, phenolic compounds and steroids. 

Kitagawa, I., T. Nishino, M. Kobayashi, and Y. Kyogoku Marine Natural Products. VIII. Bioactive Triterpene-Oligoglycosides from the Sea Cucumber Holothuria leucospilota Brandt (2). Structure of Holothurin A. Chem. Pharm. Bull. (Japan) 29, 1951 (1981). 

Kitagawa, I., Nishino, T., Kobayashi, M., and Kyogoku, Y. (1981a) Marine natural products. VIII. Bioactive triterpene-oligoglycosides from the sea cucumber Holothuria leucospilota Brandt stmcture of holothurin A. Chem. Pham. Bull, 29, 1951-1956. 

Zhang, S.-Y, Yi, Y.-H., and Tang, H.-F. (2006b) Bioactive triterpene glycosides from the sea cucumber Holothuria Juscocinerea. J. Nat. Prod., 69,1492-1495. 

Fukami, A Ikeda, Y, Kondo, S., Naganawa, H., Takeuchi, T., Furuya, S Hirabayashi, Y, Shimoike, K., Hosaka, S., Watanabe, Y, and Umezawa, K. (1997) Akaterpin, a novel bioactive triterpene from the marine sponge Callyspongia sp. Tetrahedron Lett., 38,1201-1202. 

Yoshikawa, M., Murakami, T., Ueno, T., Yashiro, K., Hirokawa, N., Murakami, N., Yamahara, J., Matsuda, H., Saijoh, R., and Tanaka, O. (1997b). Bioactive saponins and glycosides. Vlll. Notoginseng (1) New dammarane-type triterpene oligoglycosides, Notoginsenosides-A, -B, -C, and -D, from the dried root of Panax notoginseng (Burk.) F. H. Chen. Chem. Pharm. Bull. 45,1039-1045. 

A variety of plant bioactives inhibit the metallopeptidase aminopeptidase N [63-68], the most potent inhibitors (variously active at 1-7 pM) being the phenolics curcumin, phloretin and quercetin [64-67] and the lupane triterpene betulinic acid (IC5o value 7 pM) [68] (Table 2). 

If as above we simply represent alicyclic rings sharing two Gs by a vertical line, then we can represent the basic tetracyclic structure of lanosterol as G61G61 G6 C5 (noting that there are two double bonds and various alkyl substituents and also a 3-hydroxyl on the first of the alicyclic rings). Many subsequent reactions yield cholesterol, a major triterpene membrane component that modifies the fluidity of animal cell membranes and is a precursor for synthesis of animal bile acids (fat solubilizing amphipathic detergents) plant triterpenes and steroid hormones such as the corticosteroids cortisol and cortisone, the mineralocorticoid aldosterone and the sex hormones testosterone and 17-(3-oestradiol. The structure and bioactivity of the plant terpenes is sketched below. 

Djoufack, G. L. Valant-Vetschera, K. M. Schinnerl, J. Brecker, L. Lorbeer, E. Robien, W., Xanthones, biflavanones and triterpenes from Pentadesma grandifolia (Clusiaceae) structural determination and bioactivity, Nat. Prod. Commun., 2010, 5, 1055-1060. 

The bioactivity (Table 3) of this series of triterpenes is dependent on two regions of the structure (1) the olefmic chain system and (2) the carbonyl group at C-3 of aliphatic ring A. In general, cyclization of the olefmic chain system to a y-pyrone and acetylation of the carbonyl group at C-3 inreases the bioactivity of the triterpene. However, from the results of the insecticidal assay, deacetylation at C-3 apparently leads to a... 

Table 3. Bioactivities of the isomalabaricane triterpenes from Stelleta globoslellala...

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