Recent developments in iridoids chemistry

Abstract

Abstract

Revision of the Absolute Configuration of Plumericin and Isoplumericin fromPlumeria rubra

“…± More than 200 iridoids have been found to occur in nature, and the majority of them differ only in the degree and type of substituents of the basic cyclopentanopyran skeleton [1] [2]. Plumericin (1) and isoplumericin (2) are important tetracyclic members of this family, occurring mainly in the genera of Plumeria [3 ± 8], Allamanda [7] [9 ± 12], Himantanus [13], and Nerium [14]. Species of the genus Plumeria are widely used in traditional medicine [15].…”

“…In the present study, we investigated the constituents of P. rubra, and identified plumericin (1) and isoplumericin (2), as well as their analogues plumieride (3) and fulvoplumierin (4) (Fig. 1).…”

Glycogen Phosphorylase-a is a Common Target for Anti-Diabetic Effect of Iridoid and Secoiridoid Glycosides

“…Iridoids are constituted of cyclopentanoid monoterpene derivatives and can be subdivided into four groups, iridoid glycosides, simple iridoids or non glycosidic iridoids, secoiridoids and bisiridoids (10). Their presence is a characteristic of angiosperms, in particular of the super order of sympetalae (11). The name "iridoid" was probably derived from the compounds such as an iridomyrcetin, iridolactone and iridoidal, isolated from a genus of ants known as iridomyrex, where these compounds are responsible for defensive secretion of ants (12).…”

“…Chemistry and biological activity of iridoids and secoiridoids Iridoids are monoterpenoids based on a cyclopentane-[C]-pyran skeleton (Figure 1a), which may consist of ten, nine, or rarely eight carbon atoms in which C11 is more frequently missing than C10 (11,13,14,16,17). Oxidative cleavage at 7,8-bond of the cyclopentane moiety affords the so called secoiridoids (Figure 1b) (11,13,14,16,17), while cleavage of pyran ring produced iridoids derivatives (Figure 1c) (17)(18)(19)(20).…”

“…Oxidative cleavage at 7,8-bond of the cyclopentane moiety affords the so called secoiridoids (Figure 1b) (11,13,14,16,17), while cleavage of pyran ring produced iridoids derivatives (Figure 1c) (17)(18)(19)(20). The stereochemical configurations at C5 and C9 leads to cis fused rings, which is common to all iridoids containing the basic carbocyclic-or seco-skeleton in non-rearranged form.…”