Essential‐Oil Diversity of Three Calamintha Species from Greece

The aim of the present study was to contribute to the knowledge of the essential‐oil composition of the Calamintha officinalis‐nepeta complex in Greece and to clarify the main patterns of its variation. The oils obtained from 22 wild‐growing populations of C. glandulosa, C. nepeta, and C. menthifolia were studied. They could be classified into two different chemotypes, which correspond to the main biosynthetic routes of the C(3)‐oxygenated p‐menthane compounds. Chemotype I includes oils rich in trans‐piperitone oxide, cis‐piperitone oxide, and piperitenone oxide, while Chemotype II comprises oils rich in pulegone and menthone or menthone and isomenthone. Within both chemotypes, quantitative fluctuations of the main components were observed. Comparison with published data showed that the presence of Chemotype II has not been observed before in C. menthifolia, while Chemotype I has been reported in C. nepeta plants from Greece for the first time.     

国产野生薄荷挥发油化学组分变异及其化学型

采用气－质联用的方法,对国产野生薄荷（ＭｅｎｔｈａｈａｐｌｏｃａｌｙｘＢｒｉｑ．）居群的挥发油成分进行了分析,２２个样品可归纳为６个化学型：（１）薄荷酮－胡薄荷酮型（ｍｅｎｔｈｏｎｅ－ｐｕｌｅｇｏｎｅｔｙｐｅ）;（２）胡椒酮型（ｐｉｐｅｒｉｔｏｎｅｔｙｐｅ）;（３）氧化胡椒酮－氧化胡椒烯酮型（ｐｉｐｅｒｉｔｏｎｅｏｘｉｄｅ－ｐｉｐｅｒｉｔｅｎｏｎｅｏｘｉｄｅｔｙｐｅ）;（４）芳樟醇－氧化胡椒酮型（ｌｉｎａｌｏｏｌ－ｐｉｐｅｒｉｔｏｎｅｏｘｉｄｅｔｙｐｅ）;（５）香芹酮型（ｃａｒｖｏｎｅｔｙｐｅ）;（６）薄荷醇－乙酸薄荷酯型（ｍｅｎｔｈｏｌ－ｍｅｎｔｈｙｌａｃｅｔａｔｅｔｙｐｅ）。结合地理分布和薄荷属单萜类成分生物合成途径,对上述主要类型进行了讨论。     

Intraspecific Variability of the Essential Oil of Ziziphora clinopodioides ssp. rigida from Iran

Hydrodistillated essential oils of Ziziphora clinopodioides ssp. rigida from nine populations of the Lashgardar protected region (Hamedan Province, Iran) were analyzed by using GC and GC/MS techniques to determine the intraspecific chemical variability. Altogether, 39 compounds were identified in the oils, and a relatively high variation in their contents was found. The main constituents of the essential oils were pulegone (0.7–44.5%), 1,8‐cineole (2.1–26.0%), neomenthol (2.5–22.5%), 4‐terpineol (0.0–9.9%), 1‐terpineol (0.0–13.2%), neomenthyl acetate (0.0–7.1%), and piperitenone (0.0–5.4%). For the determination of the chemotypes and the intraspecific chemical variability, the essential oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (pulegone/neomenthol), Chemotype II (pulegone), Chemotype III (pulegone/1,8‐cineole), Chemotype IV (neomenthol), and Chemotype V (1,8‐cineole/4‐terpineol).     

An interpopulation study of the essential oils of Cistus parviflorus L. growing in Crete (Greece)

The composition of the essential oils of nine populations of Cistus parviflorus L., from Crete (Greece) and their interpopulation variability, were investigated by GC-MS. 114 compounds were identified representing an average of 85-96% of oil composition. Labdane diterpenes were detected and identified in the essential oils of Cistus parviflorus L. for the first time. The results obtained from GC-MS analysis of the volatile oils were submitted to principal component and chemometric cluster analysis. Two main chemotypes (clusters) were differentiated; the first of West Crete and the second of East Crete. Carvacrol, caryophyllene oxide, alpha-epi-cadinol, abietatriene, 4-epi-dehydroabietol, dehydro abietol, cis-ferruginol and manoyl oxide mixture of isomers are the main constituents, while oxygenated sesquiterpenes as well as diterpenes have been found in high percentage composition.     

Chemical and morphological diversity in wild populations of Mentha longifolia in Israel

Populations of Mentha longifolia, an endangered species in Israel, were tested for essential oil composition and conservational ability. In 2002-2003, 25 wild populations country-wide were tested, indicating population divergence into two chemotypes. Chemotype A was characterized by high levels of menthone and pulegone, and chemotype B by high levels of piperitenone oxide and piperitone oxide. Chemotype A was more abundant (22 of 25 populations) than chemotype B (11 of 25 populations). However, a chemotype/population interaction was not recorded (P?>?0.05). In spring 2003, seven of the 25 wild populations were resampled, propagated, and cultivated at the Newe Ya'ar campus. Then, in 2004, the propagated plants were tested for essential oil composition. The propagated plants maintained the essential oil composition as well as the chemotype-frequency distribution of the original wild population from which they were obtained. Since a chemotype/population interaction was not recorded, and the cultivated plants displayed the wild population essential oil composition, it can be concluded that i) the chemotype diversity is genetically based, and ii) the M. longifolia populations sampled can be horticulturally conserved.     

Chemotype Diversity of Indigenous Dalmatian Sage (Salvia officinalis L.) Populations in Montenegro

To identify how many chemotypes of Salvia officinalis exist in Montenegro, the chemical composition of the essential oils of 12 wild‐growing populations was determined by GC‐FID and GC/MS analyses. Among the 40 identified constituents, the most abundant were cis‐thujone (16.98–40.35%), camphor (12.75–35.37%), 1,8‐cineol (6.40–12.06%), trans‐thujone (1.5–10.35%), camphene (2.26–9.97%), borneol (0.97–8.81%), viridiflorol (3.46–7.8%), limonene (1.8–6.47%), α‐pinene (1.59–5.46%), and α‐humulene (1.77–5.02%). The composition of the essential oils under study did not meet the ISO 9909 requirements, while the oils of populations P02–P04, P09, and P10 complied with the German Drug Codex. A few of the main essential‐oil constituents appeared to be highly intercorrelated. Strong positive correlations were observed between α‐pinene and camphene, camphene and camphor, as well as between cis‐thujone and trans‐thujone. Strong negative correlations were evidenced between cis‐thujone and α‐pinene, cis‐thujone and champhene, cis‐thujone and camphor, as well as between trans‐thujone and camphene. Multivariate analyses allowed the grouping of the populations into three distinct chemotypes, i.e., Chemotype A, rich in total thujones, Chemotype B, with intermediate contents of thujones, α‐pinene, camphene, and camphor and high borneol contents, and Chemotype C, rich in camphor, camphene, and α‐pinene. The chemotypes did not significantly differ in the total essential‐oil content and the cis/trans‐thujone ratio.     

Chemical Diversity among the Essential Oils of Wild Populations of Stachys lavandulifolia Vahl (Lamiaceae) from Iran

The variation of the essential‐oil composition among ten wild populations of Stachys lavandulifolia Vahl (Lamiaceae), collected from different geographical regions of Iran, was assessed by GC‐FID and GC/MS analyses, and their intraspecific chemical variability was determined. Altogether, 49 compounds were identified in the oils, and a relatively high variation in their contents was found. The major compounds of the essential oils were myrcene (0.0–26.2%), limonene (0.0–24.5%), germacrene D (4.2–19.3%), bicyclogermacrene (1.6–18.0%), δ‐cadinene (6.5–16.0%), pulegone (0.0–15.1%), (Z)‐hex‐3‐enyl tiglate (0.0–15.1%), (E)‐caryophyllene (0.0–12.9), α‐zingiberene (0.2–12.2%), and spathulenol (1.6–11.1%). For the determination of the chemotypes and the chemical variability, the essential‐oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (germacrene D/bicyclogermacrene), Chemotype II (germacrene D/spathulenol), Chemotype III (limonene/δ‐cadinene), Chemotype IV (pulegone), and Chemotype V (α‐zingiberene). The high chemical variation among the populations according to their geographical and bioclimatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. The in situ and ex situ conservation strategies should concern all populations representing the different chemotypes.     

A comparative study of the essential oils of Cistus salviifolius in several populations of Crete (Greece)

The composition of the essential oils of fifteen populations of Cistus salviifolius L. (Cistaceae) from Crete (Greece) and their interpopulation variability was investigated by GC-MS. 167 compounds were identified representing an average of 96–100% of the oil composition. Labdane diterpenes were detected and identified in the essential oils of Cistus salviifolius L., for the first time. The results obtained from GC-MS analysis of the oils were submitted to a Principal Component Analysis (PCA). Three main chemotypes (clusters) were differentiated. All the essential oils were tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria. Only chemotype III having camphor as a major constituent was active against Gram-positive bacteria. Camphor, viridiflorol, longiborneol, phyllocladene, abietatriene and cis-feruginol are the main constituents, while the group of oxygenated sesquiterpenes has the highest percentage composition.     

Chemical variation in the leaf essential oil of Melaleuca quinquenervia (Cav.) S.T. Blake

An examination of the leaf oils of Melaleuca quinquenervia over its geographical range in Australia and Papua New Guinea has shown wide variation in chemical composition but only two major chemotypes. Chemotype 1 is comprised of E-nerolidol (74–95%) and linalool (14–30%) and is found from Sydney, north along the east coast of Australia to Selection Flat, New South Wales, with an isolated occurrence near Maryborough, Queensland. Two divisions occur in this chemotype which are based on the presence or absence of significant proportions of linalool (14–40%). Chemotype 2 contains 1,8-cineole (10–75%), viridiflorol (13–66%), α-terpineol (0.5–14%) and β-caryophyllene (0.5–28%) in varying proportions and order of dominance in the oils. It is found throughout the distribution of the species, from Sydney to Papua New Guinea and New Caledonia. Within chemotype 2 there appears to be a continuous spread of oil composition without formation of any further discrete divisions as in chemotype 1.Analyses have shown that M. quinquenervia trees that occur at latitudes south of 25°S have high oil yields (1–3% w/w%, fresh leaves) and comprise chemotypes 1 and 2. North of 25°S, however, chemotype 1 does not occur and oil yields amongst the Australian populations are uniformly low (0.1–0.2%).     

Essential oil of two chemotypes of Mentha suaveolens during ontogenesis

The composition of the main constituents of the essential oil of two different chemotypes of Mentha suaveolens has been investigated during development. In the first chemotype (6) a definite increase of 1,2-epoxymen-thylacetate was observed, but piperitone oxide was always the main constituent. In the second chemotype (12) an increase of neo- and dihydrocarveol and their corresponding acetates was observed and dihydrocarvone was the main constituent. The results have been used to formulate a new biosynthetic scheme for the cyclic oxygenated monoterpenes found in essential oils of the genus Mentha.     

Mentha spicata (Lamiaceae) chemotypes growing wild in Greece

Mentha spicata is the commonest mint species growing wild in Greece, exhibiting great morphological and chemical variability. The oil content from different wild populations examined ranged from 0.3% to 2.2%; the most common value being ca.1%. Though commercially exploited M. spicata plants are always rich in carvone and dihydrocarvone, wild populations are very variable; four different chemotypes were distinguished within the species. These chemotypes are characterized by the high contribution of the following compounds: (1) linalool, (2) piperitone oxide or piperitenone oxide, (3) carvone-dihydrocarvone and (4) pulegone-menthone-isomenthone. This chemical variability suggests the possibility of further developing and exploiting the full potential of the species.     

Essential oil analysis and antimicrobial activity of eight Stachys species from Greece

The volatile composition of eight Stachys species has been studied. The investigated taxa were St. alopecuros (L.) Bentham., St. scardica (Griseb.) Hayek, St. cretica L. ssp. cretica, St. germanica L. ssp. heldreichii (Boiss.) Hayek, St. recta L., St. spinulosa L., St. euboica Rech. and St. menthifolia Vis., growing wild in Greece. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the substances was made by comparison of mass spectra and retention indices with literature records. Sesquiterpene hydrocarbons were shown to be the main group of constituents of all taxa. Furthermore, the obtained essential oils were tested against the following six bacteria: Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35210), Bacillus subtilis (ATCC 10907), Bacillus cereus (clinical isolates), Micrococcus flavus (ATCC 10240), Staphylococcus epidermidis (ATCC 2228), as well as against the following five fungi: Aspergillus niger (ATCC 6275), Penicillium ochrochloron (ATCC 9112), Epidermophyton floccosum (clinical isolates), Candida albicans (clinical isolates) and Trichophyton mentagrophytes (clinical isolates). The tested essential oils showed better activity against bacterial species than against fungi. Pseudomonas aeruginosa was the most resistant strain, as none of the essential oils was active against this strain. The essential oil of St. scardica has been proven most active against both bacteria and fungi.     

Phytochemical Diversity of the Essential Oils of Mexican Oregano (Lippia graveolens Kunth) Populations along an Edapho‐Climatic Gradient

Mexican oregano (Lippia graveolens) is an important aromatic plant, mainly used as flavoring and usually harvested from non‐cultivated populations. Mexican oregano essential oil showed important variation in the essential‐oil yield and composition. The composition of the essential oils extracted by hydrodistillation from 14 wild populations of L. graveolens growing along an edaphoclimatic gradient was evaluated. Characterization of the oils by GC‐FID and GC/MS analyses allowed the identification of 70 components, which accounted for 89–99% of the total oil composition. Principal component and hierarchical cluster analyses divided the essential oils into three distinct groups with contrasting oil compositions, viz., two phenolic chemotypes, with either carvacrol (C) or thymol (T) as dominant compounds (contents >75% of the total oil composition), and a non‐phenolic chemotype (S) dominated by oxygenated sesquiterpenes. While Chemotype C was associated with semi‐arid climate and shallower and rockier soils, Chemotype T was found for plants growing under less arid conditions and in deeper soils. The plants showing Chemotype S were more abundant in subhumid climate. High‐oil‐yield individuals (>3%) were identified, which additionally presented high percentages of either carvacrol or thymol; these individuals are of interest, as they could be used as parental material for scientific and commercial breeding programs.     

Genetic and Chemical Diversity in Perovskia abrotanoides Kar. (Lamiaceae) Populations Based on ISSRs Markers and Essential Oils Profile

Genetic and the essential oil composition variability among twelve Perovskia abrotanoides populations (PAbPs) growing wild in Iran were assessed by ISSR markers, GC‐FID and GC/MS, respectively. Nine selected ISSR primers produced 119 discernible bands, of them 96 (80.7%) being polymorphic. Genetic similarity values among populations ranged between 0.07 and 0.79 which indicated a high level of genetic variation. Polymorphic information content, resolving power and marker index generated by ISSR primers were, 0.31, 6.14, and 3.32, respectively. UPGMA grouped PAbPs into four main clusters. Altogether, 38 chemical compounds were identified in the oils, and a relatively high variation in their contents was found. Camphor (11.9 – 27.5%), 1,8‐cineole (11.3 – 21.3%), α‐bisabolol (0.0 – 13.1%), α‐pinene (5.9 – 10.8%), and δ‐3‐carene (0.1 – 10.5%) were the major compounds. Oxygenated monoterpenes (32.1 – 35.8%) and monoterpene hydrocarbons (25.7 – 30.4%) were the main groups of compounds in the oils studied. Cluster analysis and principal‐component analysis were used to characterize the samples according to oil components. Four main chemotypes were found to be Chemotype I (camphor/1,8‐cineol), Chemotype II (1,8‐cineole/camphor), Chemotype III (camphor/1,8‐cineol/α‐bisabolol), and Chemotype IV (camphor/δ‐3‐carene/α‐bisabolol). The information, provided here on P. abrotanoides populations, will be useful to introduce this plant into agricultural systems.     

Antioxidant property of volatile oils determined by the ferric reducing ability

Some current oils and their main components were studied to determine their antioxidant values. This was done by using the modified method of ferric reducing ability of plasma. It has been established that volatile oils of medicinal plants have on average a reducing capacity of 3.5-220 mmol/kg oil. The reducing capacities of the main constituents of volatile oils are 0.165-65.5 mmol/kg in concentrated oils. The highest reducing capacity was showd for phellandrene (65.438 +/- 0.166 mmol/kg) and anethole (50.087 +/- 0.160 mmol/kg) while the lowest values were obtained for menthol (0.165 +/- 0.023 mmol/kg) and menthone (0.168 +/- 0.010 mmol/kg). It has been stated that the antioxidant values of the main constituents are lower than those of volatile oils. The reducing capacity of the main constituents of medicinal plant drugs at different concentrations was also determined.     

Chemical variability of peel and leaf essential oils of 15 species of mandarins

Peel and leaf oils of 58 mandarin cultivars, belonging to 15 different species were obtained from fruits and leaves collected on mandarin-trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC/MS and 13C NMR and the results were submitted to a cluster analysis and a discriminant analysis. Three major chemotypes, limonene, limonene/gamma-terpinene and linalyl acetate/limonene, were distinguished for peel oils while three other chemotypes, sabinene/linalool, gamma-terpinene/linalool and methyl N-methylanthranilate, were observed for leaf oils.     

Chemical and genetic study of Ligularia duciformis and related species in Sichuan and Yunnan Provinces of China

The chemical constituents of the root extracts and the evolutionarily neutral DNA base sequences were studied for 28 samples of Ligularia duciformis, L. kongkalingensis, and L. nelumbifolia collected in Sichuan and Yunnan Provinces of China. The samples could be classified into four chemotypes (1-4). Sesquiterpenoids having eremophilane and oplopane skeletons were isolated from two (Chemotype?1) and three (Chemotype?2) samples, respectively. Two new oplopane derivatives were isolated and their structures were determined. In 18 samples, phenylpropenoids were the major components (Chemotype?3). In five samples, neither phenylpropenoids nor sesquiterpenoids were found (Chemotype?4). Despite this large chemical variety, no correlation was found between the chemotype and the morphological criteria of species identification. The analysis of the evolutionarily neutral DNA regions also indicated that the samples were not separated into distinct clades and that introgression was extensive.     

Molecular and phenotypic descriptions of Stachybotrys chlorohalonata sp. nov. and two chemotypes of Stachybotrys chartarum found in water-damaged buildings

Twenty-five Stachybotrys isolates from two previous studies have been examined and compared, using morphological, chemical and phylogenetic methods. The results show that S. chartarum sensu lato can be segregated into two chemotypes and one new species. The new species, S. chlorohalonata, differs morphologically from S. chartarum by having smooth conidia, being more restricted in growth and producing a green extracellular pigment on the medium CYA. S. chlorohalonata and S. chartarum also have different tri5, chs1 and tub1 gene fragment sequences. The two chemotypes of S. chartarum, chemotype S and chemotype A, have similar morphology but differ in production of metabolites. Chemotype S produces macrocyclic trichothecenes, satratoxins and roridins, while chemotype A produces atranones and dolabellanes. There is no difference between the two chemotypes in the tub1 gene fragment, but there is a one nucleotide difference in each of the tri5 and the chs1 gene fragments.     

Essential Oils of Micromeria dalmatica Benth., a Balkan Endemic Species of Section Pseudomelissa

The essential oils of 13 Greek populations of Micromeria dalmatica, a Balkan endemic species and member of the section Pseudomelissa, were examined for the first time. Among the studied populations, two main oil types could be distinguished. Type I was found to be rich in β‐pinene, limonene, and germacrene D (accounting for 55.6–70.2% of the total oil), and Type II was characterized by the preponderance of p‐menthane compounds (accounting for 64.2–89.9% of the oil). The latter oil type could be further divided into two subtypes, one comprising oils with predominance of piperitenone and piperitenone oxide and another composed of oils containing high proportions of pulegone, menthone, and isomenthone. The abundance of p‐menthane compounds is a common feature of the oils of all members of the section Pseudomelissa studied to date. However, the existence of oils of Type I has not been previously reported for M. dalmatica, neither for other members of the section Pseudomelissa.     

亚洲薄荷的两个化学型

亚洲薄荷的两个化学型桂新,周荣汉（安徽中医学院中药系合肥２３００３８）（中国药科大学植物化学分类研究室南京２１００３８）ＴｗｏｃｈｅｍｏｔｙｐｅｓｏｆＭｅｎｔｈａａｓｉａｆｉｃａＢｏｒｉｓｓ￥ＣｈｏｕＧｕｉ－Ｘｉｎ（ＡｎｈｕｉＣｏｌｌｅｇｅｏｆＴｒａ...