Neo-clerodane diterpenes from Teucrium fruticans

6 pages, 1 figure, 3 tables.-- PMID: 14759529 [PubMed].-- Available online Nov 13, 2003.-- Issue title: "Reports on Structure Elucidation".In addition to three out of the four previously reported neo-clerodanes already found in Teucrium fruticans (fruticolone, isofruticolone and 8β-hydroxyfruticolone), and 6-acetylteucjaponin B (isolated from T. scordium and T. grisebachii), four new neo-clerodanes, namely 7β-hydroxyfruticolone, 11-hydroxyfruticolone, deacetylfruticolone and 6-acetyl-10-hydroxyteucjaponin B were also isolated. The structures were unambiguously elucidated based on extensive NMR spectral studies (one- and two-dimensional experiments). Semi-prep-HPLC proved to be a convenient purification procedure, occasionally being followed by TLC. The new compounds were assayed against Spodoptera littoralis and two of them were shown to have potent antifeedant activity.Financial support by MCYT grant (AGL2001/2285) and predoctoral fellowship.Peer reviewe

Isolation and structure elucidation of three neo-clerodane diterpenes from Teucrium fruticans L. (LABIATAE)

6 pages, 1 figure, 1 scheme, 5 tables.-- PMID: 16122769 [PubMed].-- Printed version published Oct 2005.-- Dedicated to Prof. Francisco Camps on the occasion of his 70th birthday.-- Issue title: "Reports on Structure Elucidation".Recently, the isolation from Teucrium fruticans of neo-clerodanes, namely 7β-hydroxyfruticolone, 11-hydroxyfruticolone, deacetylfruticolone and 6-acetyl-10-hydroxyteucjaponin B, in addition to fruticolone, isofruticolone and 8β-hydroxyfruticolone (three out of the four previously reported ones), and 6-acetylteucjaponin B (isolated from T. scordium and T. grisebachii) was reported. Minor compounds presumably of neo-clerodane nature were shown by HPLC analysis on a new extract. Three new compounds, difuranofruticol, deoxyfruticolone and 10-hydroxyteucjaponin B, and the known 7,8-didehydrofruticolone were unambiguously elucidated based on extensive NMR spectral studies (one- and two-dimensional experiments). The compounds were assayed for their antifeedant activity against Spodoptera littoralis and for their antifungal activity against Rhizoctonia solani. Compounds 9–11 showed low antifeedant activity and the feeding ratio of 12 was moderate-low. None of the tested compounds displayed significant activity against R. solani.Financial support by MCYT/MEC Grants (AGL2001/2285; AGL2004-05252) and predoctoral fellowship (to Y.T.) is gratefully acknowledged.Peer reviewe

New phytoecdysteroids from cultured plants of Ajuga nipponensis Makino

8 pages, 6 figures.-- PMID: 17210166 [PubMed].An extract from aerial parts of Ajuga nipponensis Makinowas examined by high performance liquid chromatography for minor ecdysteroids. Along with the compounds already reported, namely cyasterone, ajugasterone C, cyasterone 22-acetate and 22-dehydrocyasterone, the presence of three additional bands with the expected ecdysteroid-like UV absorption was observed. The structures of the isolates were unambiguously elucidated based on extensive NMR spectral studies (one and two-dimensional experiments) and pointed out three new phytoecdysteroids. One of the new compounds, 22-dehydrocyasterone 2-glucoside is just the second example of a C-2 glucosyl derivative. The other two compounds displayed hemiacetal functions in the side chain, one unprecedented, and were named ajugacetalsterone A and B.Financial support from MCYT (grant AGL2001/2285 and associated Beca Predoctoral de Formación de Investigadores to YAT), MEC (grant AGL2004/05252), AECI (2002CN0001) and Generalitat de Catalunya (2001SGR-00342) is gratefully acknowledged.Peer reviewe

Ectopic expression of snapdragon transcription factors facilitates the identification of genes encoding enzymes of anthocyanin decoration in tomato

Given the potential health benefits of polyphenolic compounds in the diet, there is a growing interest in the generation of food crops enriched with health-protective flavonoids. We undertook a series of metabolite analyses of tomatoes ectopically expressing the Delila and Rosea1 transcription factor genes from snapdragon (Antirrhinum majus), paying particular attention to changes in phenylpropanoids compared to controls. These analyses revealed multiple changes, including depletion of rutin and naringenin chalcone, and enhanced levels of anthocyanins and phenylacylated flavonol derivatives. We isolated and characterized the chemical structures of the two most abundant anthocyanins, which were shown by NMR spectroscopy to be delphinidin-3-(4'''-O-trans-p-coumaroyl)-rutinoside-5-O-glucoside and petunidin-3-(4'''-O-trans-p-coumaroyl)-rutinoside-5-O-glucoside. By performing RNA sequencing on both purple fruit and wild-type fruit, we obtained important information concerning the relative expression of both structural and transcription factor genes. Integrative analysis of the transcript and metabolite datasets provided compelling evidence of the nature of all anthocyanin biosynthetic genes, including those encoding species-specific anthocyanin decoration enzymes. One gene, SlFdAT1 (Solyc12g088170), predicted to encode a flavonoid-3-O-rutinoside-4'''-phenylacyltransferase, was characterized by assays of recombinant protein and over-expression assays in tobacco. The combined data are discussed in the context of both our current understanding of phenylpropanoid metabolism in Solanaceous species, and evolution of flavonoid decorating enzymes and their transcriptional networks in various plant species