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.
Key words
Cistus creticus subsp. - Cistaceae - labdane diterpenes - manoyl oxide isomers - GC and GC-MS analysis
- antimicrobial activity
