Terpenoid lactones as plant growth regulators

Sesquiterpene Lactones with Potential Use as Natural Herbicide Models (I): trans,trans-Germacranolides

“…Costunolide ( 1) is one of the two major constituents of the roots of Saussurea lappa (Kalsi et al, 1977), and it has been reported to enhance rooting in stem cuttings of Phaseolus aureus (Kalsi et al, 1983). Its activity has been related to the presence of an R-methylene moiety in the γ-lactone ring and is enhanced up to four times when replaced by a cyclopropyl ring, very tensioned and susceptible to undergo ring-opening reactions by different reagents attacking in the same way as R-methylenes do with nucleophiles (Figure 2).…”

Secondary Metabolites of Plants from the Genus Saussurea: Chemistry and Biological Activity

“…Reaction of dehydrocostuslactone (1) with CH 2 N 2 afforded a crystalline pyrazoline derivative E, which, on pyrolysis at 1008, afforded a mixure of two components F and G (Scheme 6). Activities of the lactones F and G, in which the conjugation is of different type, were slightly higher than that of the parent amethylidene-g-lactone 1 [55].…”

“…A variety of g-lactones which contain a trisubstituted C¼C bond or a cyclopropane ring conjugated with the lactone C¼O are more active than the parent a-methylideneg-lactones [55]. It has been further established that, only in the case of guaianolides, the presence of a C(4)-epoxy or a C(4)ÀOÀC(10) ether group further enhance the biological activity [210] compared with the parent lactone.…”

ChemInform Abstract: Secondary Metabolites of Plants from the Genus Saussurea: Chemistry and Biological Activity

“…A variety of g-lactones which contain a trisubstituted C¼C bond or a cyclopropane ring conjugated with the lactone C¼O are more active than the parent a-methylideneg-lactones [55]. It has been further established that, only in the case of guaianolides, the presence of a C(4)-epoxy or a C(4)ÀOÀC(10) ether group further enhance the biological activity [210] compared with the parent lactone.…”

“…[17] [18] Compounds of this group are characterized by three exocyclic CH 2 C¼C bonds: C(4)¼C (15), C(10)¼C (14), C(11)¼C (13), and differ only at C(3) and C (8). The two highly crystalline lactones, dehydrocostuslactone (1) and costunolide (99), present in several Saussurea spp., were detected in the essential oil from the roots of S. lappa at the extent of 35% and 15%, respectively [55]. Biological activities of these two compounds have been most extensively investigated: anti-ulcer [56], anticarcinogenesis in rats [57] [58], vasorelaxant effect [59], inhibitory effects on killing activity of cytotoxic T lymphocytes [60], hepatitis B virus surface antigen expression [61], and inhibition of NF-kB activation, thereby preventing iNOS and TNF-a expression [28] [62] [63].…”