Analysis of Labdane-Type Diterpenes from Cistus creticus (subsp. creticus and subsp. eriocephalus), by GC and GC-MS1

Abstract

The qualitative and quantitative analysis of labdane-type diterpenes of the hexane extracts and of the essential oils of the leaves, fruits and resin "Ladano", of Cistus creticus subsp. creticus and Cistus creticus subsp. eriocephalus, have been carried out by GC and GC-MS analysis using two capillary chromatographic columns, i.e., HP-5MS and CP-Wax. The methanolic extract of the fruits of C. creticus subsp. creticus was examined and seven labdane diterpenes were isolated and identified by spectroscopic methods. Data on the investigation of labdane diterpenes by GC and GC-MS is limited and most of them have never been analysed by this method. The results obtained by this analysis could be useful for identifying them in crude plant extracts. Manoyl oxides were studied further for the percentage content of their isomers. The hexane extracts of the two subspecies as well as the manoyl oxide isomers isolated from the methanolic extract of the fruits of C. creticus subsp. creticus, were tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria. Global numerical differences of these C. creticus subspecies, based on labdane diterpenes content in the hexane extracts as well as in the essential oils, were established by statistical methods. Phenotypic differences are discussed.

A Copal-8-ol Diphosphate Synthase from the Angiosperm Cistus creticus subsp. creticus Is a Putative Key Enzyme for the Formation of Pharmacologically Active, Oxygen-Containing Labdane-Type Diterpenes

“…The expression pattern of CcCLS suggests involvement of the encoded enzyme in labdane diterpene biosynthesis, since the preferential expression of CcCLS in the trichomes is consistent with the observed accumulation of manoyl oxide derivatives in trichome exudates of C. creticus (Anastasaki et al, 1999). Moreover, the elevated CcCLS transcript levels observed in trichomes isolated from young leaves are also consistent with the higher labdane-type diterpene concentrations in that developmental stage than in fully expanded leaves.…”

“…We show that the protein encoded by CcCLS catalyzes the formation of stable copal-8-ol diphosphate from GGDP. Alkaline phosphatase treatment of this phosphorylated intermediate resulted in the formation of labd-13-ene-8a,15-diol, which is an abundant compound in the resin of C. creticus (Demetzos et al, 1994;Anastasaki et al, 1999). Therefore, it is possible that copal-8-ol diphosphate is indeed the precursor of this compound in vivo as well.…”

Transcriptome analysis approaches for the isolation of trichome-specific genes from the medicinal plant Cistus creticus subsp. creticus

“…Several peaks, mainly corresponding to labdane-type diterpenes, other diterpenes and sesquiterpenes, were determined after extraction of lipophilic compounds with hexane and GC/MS analysis. The detected compounds were identified with comparison of their mass spectra to those of authentic samples, using retention indices and bibliographic data (Anastasaki et al 1999;Demetzos et al 1999). Qualitative analysis of the constituents showed the existence of sesquiterpenes and diterpenes with predominant the labdane-type diterpenes (Fig.…”

“…Main constituents of the aqueous extracts of Cistus species are flavonoids, whilst lipophilic extracts are enriched in labdane-type diterpenes ). Among the compounds isolated and characterized are quercetin, flavan-3-ols, kaempferol and kaempferol-3-methyl ether, aesculin, myrecitin and various labdane-type diterpenes (Anastasaki et al 1999;Chinou et al 1994;Danne et al 1994;Demetzos et al 1989;Vogt and Gulz 1986). In particular, (13E)-labda-13-en-8a,15-diol and (13E)-labda-7,13-dienol, compounds belonging to the latter group, exhibited cytotoxic activity against human leukemic cell lines (Matsingou et al 2005(Matsingou et al , 2006 and sclareol [(13R)-labda-14-en-8,13-diol] caused induced apoptosis in leukemia T-cell lines and in human breast cancer cells .…”

Análise de terpenóides de espécies de Croton sect. Lamprocroton (Mull. Arg.) Pax (Euphorbiaceae)

“…Em outro estudo, extratos hexânicos de Cistus creticus (Cistaceae, Malvales), com altas taxas de labdanos, apresentaram atividade antimicrobiana (Anastasaki et al, 1999).…”