The core structure of the iridoid monoterpenes is formed by a unique cyclization reaction. The enzyme that catalyzes this reaction, iridoid synthase, is mechanistically distinct from other terpene cyclases. Here we describe the synthesis of two substrate analogs to probe the mechanism of iridoid synthase. Enzymatic assay of these substrate analogs along with clues from the product profile of th...

Nepetalactones are iridoid monoterpenes with a broad range of biological activities produced by plants in the Nepeta genus. However, none of the genes for nepetalactone biosynthesis have been discovered. Here we report the transcriptomes of two Nepeta species, each with distinctive profiles of nepetalactone stereoisomers. As a starting point for investigation of nepetalactone biosynthesis in Ne...

1. Like other checkerspots, Euphydryas gillettii butterflies may contain the defensive chemicals, iridoid glycosides, which are sequestered from their hostplants during larval feeding. 2. We analysed the iridoid glycoside content of E.gillettii adults from two different populations, Warm Lake, Idaho, and Granite Creek, Wyoming, that have different patterns of hostplant use. 3. Gas chromatograph...

Sixteen compounds were isolated from the MeOH extract of leaves of Myoporum bontioides. The five compounds hitherto unknown, were elucidated to be a chlorine-containing iridoid, named myopochlorin, and an iridoid glucoside, an acylated iridoid glucoside, a linear acetogenin glucoside, and an acyclic monoterpene glucoside, named myobontiosides A-D, respectively, by means of spectroscopic analyses.

To verify the anti-inflammatory potency of iridoids, seven iridoid glucosides (aucubin, catalpol, gentiopicroside, swertiamarin, geniposide, geniposidic acid and loganin) and an iridoid aglycone (genipin) were investigated with in vitro testing model systems based on inhibition of cyclooxygenase (COX)-1/-2 enzymes, the tumor necrosis factor-α (TNF-α) formation and nitric oxide (NO) production. ...

Two iridoid glucosides, catalpol and aucubin, one chlorinated iridoid aglycon, rehmaglutin D were isolated from the iridoid fraction of the aerial parts of Plantago lagopus L. together with the megastigman glucoside, phlomuroside. The structures of the isolated compounds were identified by means of spectroscopic (UV, HR-ESI, 1H-NMR, 13C NMR , HMQC, HMBC, COSY) methods. This is the first report ...

From 19 species of Galium, members of 6 European sections of the genus, 24 compounds were isolated, namely 16 iridoid glucosides, 2 secoiridoid glucosides and 6 triterpene saponins (the later found only in G. rivale (Sibth. & Sm. Griseb.) The iridoid content was analyzed by thin layer chromatography - densitometry. An effort was made to clarify interspecies relationships, based on the obtained ...

Micellar electrokinetic chromatography (MEKC) was used for the separation and determination of two iridoid glycosides, aucubin and catalpol, in several Plantago species growing in Croatia: P. altissima L., P. argentea Chaix, P. coronopus L., P. holosteum Scop. (subsp. depauperata, subsp. holosteum and subsp. scopulorum), P. lagopus L., P. lanceolata L., and P. maritima L. Hot water extraction (...

A new iridoid glucoside, cornusoside A (1), and four new natural product iridoid aglycones, cornolactones A-D (2-5), together with 10 known compounds were isolated from the leaves of Cornus florida. The structures of compounds 1-5 were established by interpretation of their spectroscopic data. Cornolactone B (3) is the first natural cis-fused tricyclic dilactone iridoid containing both a five- ...

The Glanville fritillary butterfly (Melitaea cinxia) in Finland feeds on the plants Plantago lanceolata and Veronica spicata. These two plant species are distributed heterogeneously and both vary spatially and temporally in iridoid glycoside concentrations. We investigated the associations of plant species and iridoid glycoside (aucubin and catalpol) concentrations with weight, development rate...