Iridoids structure

In the cyclopentanoid monoterpene family, compounds containing an iridoid-structure exhibit various bioactivities in Nature. For example, dehydroiridodiol, isolated from dry leaves of the cat-attracting plant Actinidia polygama Miq., is known to be an attractant for the male adults of the Chrysopidae and shows activity in amounts as small as lO"" pg [35]. Dehydroiridodial, a more oxidized product, was isolated as a pungent principle of Actinidia polygama Miq. and was characterized by T. Sakan et al. in 1978 [36]. 

Valepotriatas iridoids from Valeriana and Ken-tranthus spp. Valeriana officinalis contains up to 5 % V., which are responsible for the sedative properties of this drug. Hydroxyl groups on the iridoid structure are esterified with isovaleric acid. Hydrolysis of the esters with HCl causes decomposition of the unstable alcohol moiety with production of a blue color. The most important representative is Valtratum (see). 

From the plant Escallonia pulvemlenta (Escalloniaceae), which grows in Chile, an iridoid gluco-side of elemental composition CigZ/j On was isolated. Formula / gives the structure of the iridoid glucoside skeleton... 

The neotropical staphylenid Leistrotrophus versicolor use volatile compounds secreted from their abdominal tips to attract their prey, drosophilid and phorid flies [ 116]. The structures of the active compounds are yet unknown, however, it has been speculated that actinidine or other iridoids, typically found in the defensive gland which are located at the abdominal tips of these beetles, may be key components [117]. 

Kupchan SM, Dessertine AL, Blaylock BT, Bryan RF. Isolation and Structural Elucidation of Allamandin, an Antileukemic Iridoid Lactone from Allamanda cathartica. Journal of Organic Chemistry 1974 39(17) 2477-2482. 

Glycosides can be classified on the basis of the structural types of aglycone present in the glycoside. For example, in anthraquinone, flavonoid, iridoid, lignan or steroid glycosides, the aglycones are anthraquinone, flavonoid, iridoid, lignan or steroid, respectively. 

The iridoid monoterpenoid part of the structure C-1-C-9-C-5-C-6-C-7 (B) is confirmed by the ////COSY plot ... 

Cyclopentanes, Iridoids.—The nomenclature, structure, and methods of isolation of iridoid glucosides have been reviewed 167 the occurrence of iridoids in the angio-sperms has also been reviewed.168... 

The structure for valerosidate is incorrect in the previous Report (Vol. 5, p. 17). A new valepotriate has been isolated from Valeriana officinalis and shown spectroscopically to be 7-epideacetylisovaltrate (103) 193 it is also shown to be related to didrovaltrate (104) stereochemically, but in view of the recently reported absolute configuration of didrovaltrate (104)192 this assignment must be questioned. The occurrence of iridoids in the Argentine ant Iridomyrmex humilis has been re-investigated.194... 

Stephens next examined the related iridoid prismatomerin 31. The OR of plumericin 30 is [aJo = -1-204. The structurally related prismatomerin 31 has... 

A quite unusual prunasin derivative, in which the prunasin moiety is attached to an iridoid-monoterpene, was found in Canthium schimperianum (Schwarz et al, 1996). The biological significance of these complex structures is still unknown. Their structures are comprehensively reviewed by Seigler (1991) and Muller and Seigler (1998). 

---