Monoterpenoid glycosides

N.A. Monoterpenoid glycosides, paenoiflorin, albiflorin, benzoic acid, pentagalloyl glucose.153 Antispasmodic, tonic, astringent, analgesic. 

Ishikawa et al. (2003) could obtain 33 compounds, including two new monoterpenoids, four new monoterpenoid glycosides, two new monoterpenoid glucoside sulphates and two new aromatic compound glycosides, from the water-soluble portion of the methanol extract of coriander fruit. Their structures were clarified by spectral investigation. The major constituents of coriander essential oils (dried fruits, herb prior to flowering and flowering herb) are listed below. 

Dembitsky VM. Astonishing diversity of natural surfactants 7. Biologically active hemi- and monoterpenoid glycosides. Lipids 2006 41 1-27. 

The family Rubiaceae consists of about 450 genera and 6500 species of tropical and subtropical trees, shrubs, climbers, and herbs that are known to abound with iri-doid glycosides (monoterpenoid alkaloids, tannins, and anthraquinones). When looking for Rubiaceae in field collection, one is advised to look for plants with opposite simple leaves with an interpetiolar stipule, tubular flowers, which are often white, and capsules, berries, or drupes. 

Iridoids represent a class of 941 known cyclopentano[c]pyran monoterpenoids [3] and have been reported with hepatoprotective, choleretic, vasoconstriction, anti-viral, anti-microbial, anti-inflammatory and analgesic activities. Seven iridoid glycosides, isolated from Scrophularia scorodonia L. (Scrophulariaceae), have been evaluated for effects on PGE2, and LTC4 production using calcium ionophore stimulated mouse peritoneal... 

Monoterpenoid Alkaloids.—Corynantheine-Heteroyohimbine- Yohimbine Group, and Related Oxindoles. The leaves of Strychnos decussata (Pappe) Gil. contain a new glycosidic alkaloid for which the gross structure (78) has been proposed 52 so far, nothing is known about its stereochemistry. Nevertheless it seems distinctly possible that this alkaloid is a close biosynthetic relative of vallesiachotamine. 

Iridoids are derivatives of monoterpenes and occur usually, but not invariably, as glycosides.100,101 Structurally, they are cyclopentano [r] pyran monoterpenoids and they provide a biogenetical and chemotaxonomical link between terpenes and alkaloids. The cleavage of the cyclopentane ring of iridoids produces secoiridoids.10... 

Although there has been considerable debate concerning the stereochemistry of the initial precursor of indole alkaloids, it is now firmly established that all naturally occurring monoterpenoid indole alkaloids are derived from strictosidine (3) (Battersby et al., 1978 Brown et al., 1978 Scott, 1981 Stockigt and Zenk, 1977). This alkaloidal glycoside... 

Iridoids are synthesised through the mevalonic acid pathway and are technically known as cyclopentan-[c]-pyran monoterpenoids. They occur mainly as glycosides althongh non-glycosidic iridoids also occur— these are covered in Chapter 5. The name iridoid is derived from the common Anstralian meat ant Iridomyrex detectus, from which it was first detected in 1956 (Sticher 1977). Iridoid glycosides are derived from plants belonging to many families, most notably the Rubiaceae, Lamiaceae, Scrophulariaceae and Gentianaceae. 

Chiang LC, Ng LT, Chiang W, Chang MY, Lin CC (2003) Immunomodulatory activities of flavonoids, monoterpenoids, triterpenoids, iridoid glycosides and phenolic compounds of Plantago species. Planta Med 69 600-604... 

Iridoids are monoterpenoids with a cyclopentane fused to a tetrahydropyran ring. In secoiridoids, the cyclopentane ring is opened. Most of these compounds are nonvolatile glycosides and will be reviewed elsewhere. 

Additionally, monoterpene glycosides have been reported in some plants. They are regarded as precursors of the volatile oil components [6]. As an example, among the glycosidically bound volatiles isolated from Juniperus communis were the monoterpenoids thymoquinone and p-cymen-8-ol [7]. 

The extensive isolation of iridoid glycosides from the plants of various families and exploration of their pharmacological potentials provide us new insights for utilization of these wild resources either the pure chemicals or their erode extracts for development of new natural drugs. Recent biosynthetic studies on iridoids also reveal us a new concept for synthesis of iridoid monoterpenoids via MEP pathway rather than well-known MVA pathway for terpenoid and steroid biosynthesis in higher plants. The traditional use of iridoid-rich plants as food, nutraceutical, cosmetic, and pharmaceutical industries is well justified, and their wide-scale use and cultivation may be popularized for maintenance of good health and as potential source of raw materials for pharmaceutical industries. 

Analytical and preparative h.p.l.c. of a wide range of water-soluble glycosides has been accomplished on silica with a water-containing eluant, impressive separations of cardiac, monoterpenoid,... 

---