A Chemometric Interpopulation Study of the Essential Oils of Cistus creticus L. Growing in Crete (Greece)

Abstract

The chemical composition of the essential oils of twenty-five populations of Cistus creticus subsp. creticus L. from the island of Crete (Greece) and their interpopulation variability were analysed in detail by GC-MS. 142 compounds were identified representing an average of 56.8Ð89.8% of the oil composition. The components are represented here by homologous series of monoterpenes, oxygenated monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, diterpenes, labdane diterpenes, aldehydes, alkanes, esters, fatty acids, ketones, and others. Labdane diterpenes were detected and identified in the essential oils and have been found in high percentage composition. The results from the chemical analysis of the essential oils were submitted to chemometric cluster analysis in order to detect some pattern distribution and to identify which constituents can differentiate the groups of individuals. Two main chemotypes (clusters) were well differentiated; the first deals with eight populations of West Crete and the second with the rest of the populations. Cluster analysis based on labdane type diterpenes patterns, proved to be the best chemotype for the examined populations among the other chemical groups.

Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties

“…Also, a chemometric interpopulation study of C. creticus in the East and West parts of Crete showed the existence of a high variability within the essential oils. The plants were geographically divided into three groups, two in the West and one in the Eastern part of Crete (Demetzos et al, 2002a). …”

“…Several populations of C. creticus are spread in central-eastern Mediterranean, including Corsica and Sardinia (Falchi et al, 2009) and the island of Crete in Greece (Demetzos et al, 2002a). Among the three C. creticus subspecies identified, subsp.…”

“…More than twenty five populations of subsp. creticus are endemic to the coastal areas of Crete (Greece) (Demetzos et al, 2002a). Subspecies eriocephalus is exclusive to the Mediterranean area (Demetzos et al, 2001), mainly located on the islands of Corsica, Sardinia (Paolini et al, 2009), and Crete (Demetzos et al, 1997).…”

Interpopulation Variability in the Essential Oil Composition of Cistus creticus subsp. eriocephalus from Sardinia

“…The variation of labdane diterpenes may be due to several microenviromental parameters, which are probably caused by a combination of irradiance, climate, nutrients, water availability, etc . Since labdane diterpenes are interesting compounds having biological activities, their variability has a possible ecological role of improving the defence of plants against microbial attack or insect and animal predation …”

Organic speciation of atmospheric particles in Alvão Natural Park (Portugal)

“…Within the class of labdanes, manoyl oxide and 13-epi-manoyl oxide have been identified in the ANP aerosol samples. These natural bicyclic diterpenes are abundant components of the essential oils of tens of plants belonging to the rock rose family (Cistaceae), native of the Mediterranean region (Demetzos et al 2002). One of the most abundant biogenic ketones present in the aerosol samples was 6,10,14-trimethylpentadecan-2-one, also called phytone or hexahydrofarnesyl acetone.…”