Volatile‐Oils Composition,and Bioactivity of the Essential Oils of Plectranthus barbatus,P. neochilus,and P. ornatus Grown in Portugal

Volatile‐oils chemical composition and bioactivity of the essentail oils from Plectranthus barbatus, P. neochilus, and P. ornatus (Lamiaceae) were assessed. Aerial parts from these three related Plectranthus species were collected from cultivated plants grown in Portugal, during vegetative and flowering phases. Volatiles, isolated by distillation? extraction, were analyzed by GC and GC/MS. Monoterpene hydrocarbons (12–74%) and sesquiterpene hydrocarbons (4–45%) constituted the main fractions in all volatiles. α‐Pinene ( 3 ; 12–67%), oct‐1‐en‐3‐ol ( 6 ; traces–28%), β‐pinene ( 7 ; 0.1–22%), and β‐caryophyllene ( 50 ; 7–12%) dominated P. barbatus volatiles. P. neochilus major volatile components were α‐terpenyl acetate ( 41 ; traces–48%), α‐thujone ( 2 ; 2–28%), β‐caryophyllene ( 50 ; 2–28%), β‐pinene ( 7 ; 1–25%), and α‐pinene ( 3 ; 1–19%). Oct‐1‐en‐3‐ol ( 6 ; 13–31%), β‐pinene ( 7 ; 11–24%), α‐pinene ( 3 ; 11–19%), and β‐caryophyllene ( 50 ; traces–11%) were the main constituents from P. ornatus volatiles. These chemical compositions were rather different from those previously found for specimens harvested in Africa and Brazil. Moreover, the volatiles from the flowers are herewith reported for the first time. Essential oils, isolated by hydrodistillation from leaves and stems, showed a yellowish color and unpleasant odor, with yields ranging from 0.08% to 0.84% (v/dry weight). Antioxidant and antimicrobial activities of the essential oils were evaluated by DPPH^. and TBARS assays, and agar disc‐diffusion method, respectively. Results showed low or moderate antioxidant capacity and significant antimicrobial activity against Gram‐positive bacteria.     

Composition, and antimicrobial and remarkable antiprotozoal activities of the essential oil of rhizomes of Aframomum sceptrum K. Schum. (Zingiberaceae)

The essential oil from the rhizomes of Aframomum sceptrum (Zingiberaceae) was analyzed by GC/MS, and its major constituents were found to be β‐pinene (12.7%), caryophyllene oxide (10.0%), and cyperene (6.0%). The oil was also evaluated for antimicrobial activities, in comparison with β‐pinene, caryophyllene oxide, and the leaf essential oil of Melaleuca alternifolia (Myrtaceae). The A. sceptrum essential oil exhibited bacteriostatic activity against the Gram‐positive bacteria Bacillus subtilis, Staphylococcus epidermidis, and S. aureus, but not against Gram‐negative bacteria. Moreover, it showed mild fungicidal activity against Candida albicans and Aspergillus fumigates, and remarkable antiprotozoal activity against Trypanosoma brucei brucei (MLC of 1.51 μl/ml) and Trichomonas vaginalis (IC₅₀ of 0.12±0.02 and MLC of 1.72 μl/ml).     

Chemical Variability of Cleistopholis patens (Benth.) Engl. et Diels Leaf Oil from Ivory Coast

The chemical composition of 48 leaf oil samples isolated from individual plants of Cleistopholis patens (Benth .) Engl. et Diels harvested in four Ivoirian forests was investigated by GC‐FID (determination of retention indices), GC/MS, and ¹³C‐NMR analyses. The main components identified were β‐pinene (traces–59.1%), sabinene (traces–54.2%), (E)‐β‐caryophyllene (0.3–39.3%), linalool (0.1–38.5%), (E)‐β‐ocimene (0.1–33.2%), germacrene D (0.0–33.1%), α‐pinene (0.1–32.3%), and germacrene B (0–21.2%). The 48 oil compositions were submitted to hierarchical clustering and principal components analyses, which allowed the distinction of three groups within the oil samples. The oil composition of the major group (Group I, 33 samples) was dominated by (E)‐β‐caryophyllene and linalool. The oils of Group II (eight samples) contained mainly β‐pinene and α‐pinene, while those of Group III (seven samples) were dominated by sabinene, limonene, and β‐phellandrene. Moreover, the compositions of the Ivoirian C. patens leaf oils differed from those of Nigerian and Cameroonian origins.     

Potential for host shifting in Papilio palamedes following invasion of laurel wilt disease

In the southeastern US, laurel wilt disease (LWD) is causing widespread mortality of species in the Lauraceae. The principal target, Persea borbonia, is the primary larval host of Papilio palamedes, which is known to feed on other Lauraceae species. Among these potential hosts, the exotic Cinnamomum camphora is the only species that has shown resistance to LWD. We hypothesized that oviposition preference for C. camphora and P. borbonia would correspond to larval performances on these species and that the relative host suitability of C. camphora would indicate an opportunity for host-switching. We used laboratory experiments and field observations to compare performance and preference of P. palamedes between C. camphora and P. borbonia foliage. Our results indicate moderate survivorship on C. camphora compared to P. borbonia and no differences in first and fourth instar growth rates between treatments. Fourth instars consumed relatively less of C. camphora foliage compared to that of P. borbonia, but metabolic efficiency did not differ between treatments. Rearing on the foliage of P. borbonia stump sprouts from LWD-infected trees resulted in significantly higher growth rates and metabolic efficiency as first and fourth instars, respectively. In the field and laboratory, we found no oviposition preference for C. camphora. While females laid eggs on C. camphora during laboratory trials, the same number of eggs was also laid on inanimate objects. We conclude that C. camphora is suitable for larval development but host-switching to this species by P. palamedes will be primarily constrained by the ecological factors that govern oviposition behaviors.     

Evolution of Volatile Emission in Rhus coriaria Organs During Different Stages of Growth and Evaluation of the Essential Oil Composition

Rhus coriaria, also known as Sumac, has been traditionally used in many countries as spice, condiment, dying agent, and medicinal herb. The chemical composition of essential oils (EOs) and the volatile emissions from different organs of this species collected in Sicily (Italy) were analyzed by gas chromatography‐flame ionization detection and gas chromatography/mass spectrometry. Monoterpene and sesquiterpene hydrocarbons were the most abundant class in the volatile emissions with β‐caryophyllene and α‐pinene were the main constituents in the majority of the examined samples. The EO composition was characterized by high amount of monoterpene and sesquiterpene hydrocarbons together with diterpenes. The main compounds in the EO obtained from the leaves and both stages of fruit maturation were cembrene and β‐caryophyllene, while α‐pinene and tridecanoic acid were the key compounds in the flower EO. All the data were submitted to multivariate statistical analysis showing many differences among the different plant parts and their ontogenetic stages.     

Composition and Chemical Variability of Cleistopholis patens Trunk Bark Oil from Côte d'Ivoire

The chemical composition of trunk bark oil from Cleistopholis patens (Benth .) Engl . & Diels , growing wild in Côte d'Ivoire, has been investigated by GC (FID) in combination with retention indices, GC/MS and ¹³C‐NMR. Moreover, one oil sample has been subjected to CC and all the fractions analyzed by GC (RI) and ¹³C‐NMR. In total, 61 components have been identified, including various sesquiterpene esters scarcely found in essential oils. ¹³C‐NMR was particularly efficient for the identification of a component not eluted on GC and for the quantification of heat‐sensitive compounds. Then, 36 oil samples, isolated from trunk bark harvested in six Ivoirian forests have been analyzed. The content of the main components varied drastically from sample to sample: (E)‐β‐caryophyllene (0.4 – 69.1%), β‐pinene (0 – 57%), α‐phellandrene (0 – 33.2%), α‐pinene (0.1 – 30.6%), β‐elemol (0.1 – 29.9%), germacrene D (0 – 25.4%), juvenile hormone III (0 – 22.9%), germacrene B (0 – 20.6%) and sabinene (tr‐20.3%). Statistical analysis, hierarchical clustering and principal components analysis, carried out on the 36 compositions evidenced a fair chemical variability of the stem bark oil of this species. Indeed, three clusters have been distinguished: the composition of group I (ten samples) was dominated by β‐pinene and α‐pinene, group II (nine samples) was represented by α‐phellandrene and p‐cymene and group III (16 samples) by β‐elemol. A sample displayed an atypical composition dominated by (E)‐β‐caryophyllene.     

Essential‐Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps

The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra ) from the Julian Alps were investigated by GC‐FID and GC/MS analyses. In total, 54 of the 57 detected essential‐oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ‐car‐3‐ene, β‐phellandrene, α‐pinene, β‐myrcene, and β‐pinene and the sesquiterpene β‐caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal‐component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II.     

Essential‐Oil Composition of the Needles Collected from Natural Populations of Macedonian Pine (Pinus peuce Griseb.) from the Scardo‐Pindic Mountain System

The needle‐terpene profiles of two natural Pinus peuce populations from the Scardo‐Pindic mountain system (Mt. O?ljak and Mt. Pelister) were analyzed. Among the 90 detected compounds, 87 were identified. The dominant constituents were α‐pinene (45.5%), germacrene D (11.1%), β‐pinene (10.8%), and camphene (10.3%). The following eight additional components were found to be present in medium‐to‐high amounts (0.5–10%): bornyl acetate (5.0%), β‐phellandrene (3.4%), β‐caryophyllene (2.9%), β‐myrcene (0.9%), germacrene D‐4‐ol (0.9%), tricyclene (0.7%), (E)‐hex‐2‐enal (0.7%), and bicyclogermacrene (0.6%). Although the general needle‐terpene profiles of the populations from Mt. O?ljak and Mt. Pelister were found to be similar to those of the populations from Zeletin, Sjekirica, and Mokra Gora (Dinaric Alps), principle component analysis (PCA) of eight terpenes (α‐pinene, β‐myrcene, α‐terpinolene, bornyl acetate, α‐terpinyl acetate, β‐caryophyllene, trans‐β‐farnesene, and germacrene D) in 139 tree samples suggested a divergence between the two population groups, i.e., the samples from the Scardo‐Pindic mountain system and those from the Dinaric Alps. Genetic analysis of the β‐pinene content demonstrated a partial divergence between the two geographical groups. The profiles of both population groups differed from those published for populations from the Balkan‐Rhodope mountains system (literature results), which were characterized by high contents of bornyl acetate and citronellol (Greek populations) or δ‐car‐3‐ene (Bulgarian populations).     

Chemical Variability of Xylopia quintasii Engl. & Diels Leaf Oil from Côte d'Ivoire

The chemical composition of 42 essential‐oil samples isolated from the leaves of Xylopia quintasii harvested in three Ivoirian forests was investigated by GC‐FID, including the determination of retention indices (RIs), and by ¹³C‐NMR analyses. In total, 36 components accounting for 91.9–92.6% of the oil composition were identified. The content of the main components varied drastically from sample to sample: (E)‐β‐caryophyllene (0.9–56.9%), (Z)‐β‐ocimene (0.3–54.6%), β‐pinene (0.8–27.9%), α‐pinene (0.1–22.8%), and furanoguaia‐1,4‐diene (0.0–17.6%). The 42 oil compositions were submitted to hierarchical cluster and principal components analysis, which allowed the distinction of three groups within the oil samples. The composition of the oils of the major group (22 samples) was dominated by (E)‐β‐caryophyllene. The oils of the second group (12 samples) contained β‐pinene and α‐pinene as the principal compounds, while the oils of the third group (8 samples) were dominated by (Z)‐β‐ocimene, germacrene D, (E)‐β‐ocimene, and furanoguaia‐1,4‐diene. The oil samples of Group I and II came from clay‐soil forests, while the oil samples belonging to Group III were isolated from leaves harvested in a sandy‐soil forest.     

Influences of host volatiles on feeding behaviour of the Japanese pine sawyer, Monochamus alternatus

Abstract: Choice and no‐choice feeding assays on the twigs of three host species demonstrated the following feeding preference sequence by Monochamus alternatus: Pinus massoniana > Cedrus deodara > Pinus thunbergii. There were significant differences in the concentrations of α‐pinene, camphene, d ‐limonene, β‐phellandrene, longifolene and β‐caryophyllene in volatiles emitted by twigs among the three species. We tested the effects of six monoterpenes (α‐pinene, β‐pinene, 3‐carene, myrcene, limonene and β‐caryophyllene) added to an artificial diet consisting of bark from P. thunbergii on consumption rates by M. alternatus. The addition of α‐pinene at all four concentrations 0.4, 1.2, 3.6 and 10.8 μl/ml resulted in increases of a twofold greater consumption rate than the control at a concentration of 3.6 μl/ml. Limonene inhibited diet consumption at concentrations >0.4 μl/ml. The concentration of α‐pinene in volatiles emitted by twigs was significantly higher for P. massoniana than for P. thunbergii, whereas the reverse was true for limonene. There were no differences for any of the other host components, suggesting that α‐pinene and limonene may play an important role in the adult's selection and acceptance of suitable and unsuitable feed host. Mixed compounds promoted the consumption of artificial diet at a concentration of 0.4 μl/ml, whereas consumption was inhibited at a concentration of 10.8 μl/ml. There were significant linear correlations (β‐pinene: r² = 0.930, P < 0.05; myrcene: r² = 0.933, P < 0.05) between the amount of diets consumed and diet concentrations of β‐pinene and myrcene. In conclusion, host volatile terpenes may stimulate or repel M. alternatus depending on terpene concentrations they encounter during initial feeding and then possibly inhibit further feeding activity once concentrations increase to threshold levels.     

Population Variability of Essential Oils of Pinus heldreichii from the Scardo‐Pindic Mountains Ošljak and Galičica

The needle‐terpene profiles of two natural Pinus heldreichii populations from Mts. O?ljak and Gali?ica (Scardo‐Pindic mountain system) were analyzed. Among the 68 detected compounds, 66 were identified. The dominant constituents were germacrene D (28.7%), limonene (27.1%), and α‐pinene (16.2%). β‐Caryophyllene (6.9%), β‐pinene (5.2%), β‐myrcene (2.3%), pimaric acid (2.0%), α‐humulene (1.2%), and seven additional components were found to be present in medium‐to‐high amounts (0.5–10%). Although the general needle‐terpene profile of the population from Gali?ica was similar to those of the populations from Lov?en, Zeletin, Bjelasica, and Zlatibor‐Pe?ter (belonging to the Dinaric Alps), the principle‐component analysis (PCA) of seven terpenes (β‐myrcene, limonene, β‐elemene, β‐caryophyllene, α‐humulene, δ‐cadinene, and germacrene D‐4‐ol) in 121 tree samples suggested a partial divergence in the needle‐terpene profiles between the populations from the Scardo‐Pindic mountain system and the Dinaric Alps. According to previously reported data, the P. heldreichii samples from the Balkan‐Rhodope mountains lack β‐caryophyllene and germacrene D, but contain γ‐muurolene in their terpene profile. Differences in the terpene composition between populations growing in the three above‐mentioned mountain systems were compared and discussed.     

Chemical Composition of the Essential Oils from Different Morphological Parts of Pinus cembra L.

The essential oils from needles, twigs, bark, wood, and cones of Pinus cembra were analyzed by GC‐FID, GC/MS, and ¹H‐NMR spectroscopy. More than 130 compounds were identified. The oils differed in the quantitative composition. The principal components of the oil from twigs with needles were α‐pinene (36.3%), limonene (22.7%) and β‐phellandrene (12.0%). The needle oil was dominated by α‐pinene (48.4%), whereas in the oil from bark and in the oil from twigs without needles there were limonene (36.2% and 33.6%, resp.) and β‐phellandrene (18.8% and 17.1%, resp.). The main constituents of the wood oil as well as cone oil were α‐pinene (35.2% and 39.0%, resp.) and β‐pinene (10.4% and 18.9%, resp.). The wood oil and the cone oil contained large amounts of oxygenated diterpenes in comparison with needle, twig, and bark oils.     

Antitumor Effect of the Essential Oil from Leaves of Guatteria pogonopus (Annonaceae)

Guatteria pogonopus Martius , a plant belonging to the Annonaceae family, is found in the remaining Brazilian Atlantic Forest. In this study, the chemical composition and antitumor effects of the essential oil isolated from leaves of G. pogonopus was investigated. The chemical composition of the oil was determined by GC‐FID and GC/MS analyses. The in vitro cytotoxicity was evaluated against three different tumor cell lines (OVCAR‐8, NCI‐H358M, and PC‐3M), and the in vivo antitumor activity was tested in mice bearing sarcoma 180 tumor. A total of 29 compounds was identified and quantified in the oil. The major compounds were γ‐patchoulene (13.55%), (E)‐caryophyllene (11.36%), β‐pinene (10.37%), germacrene D (6.72%), bicyclogermacrene (5.97%), α‐pinene (5.33%), and germacrene B (4.69%). The essential oil, but neither (E)‐caryophyllene nor β‐pinene, displayed in vitro cytotoxicity against all three tumor cell lines tested. The obtained average IC₅₀ values ranged from 3.8 to 20.8 μg/ml. The lowest and highest values were obtained against the NCI‐H358M and the OVCAR‐8 cell lines, respectively. The in vivo tumor‐growth‐inhibition rates in the tumor‐bearing mice treated with essential oil (50 and 100 mg/kg/d) were 25.3 and 42.6%, respectively. Hence, the essential oil showed significant in vitro and in vivo antitumor activity.     

Volatiles as Chemosystematic Markers for Distinguishing Closely Related Species within the Pinus mugo Complex

Headspace solid‐phase microextraction (HS‐SPME) coupled to GC/MS analysis was used to identify the constituents of pine‐needle volatiles differentiating three closely‐related pine species within the Pinus mugo complex, i.e., P. uncinata Ramond ex DC., P. uliginosa G.E.Neumann ex Wimm ., and P. mugo Turra . Moreover, chemosystematic markers were proposed for the three analyzed pine species. The major constituents of the pine‐needle volatiles were α‐pinene (28.4%) and bornyl acetate (10.8%) for P. uncinata, δ‐car‐3‐ene (21.5%) and α‐pinene (16.1%) for P. uliginosa, and α‐pinene (20%) and δ‐car‐3‐ene (18.1%) for P. mugo. This study is the first report on the application of the composition of pine‐needle volatiles for the reliable identification of closely‐related pine species within the Pinus mugo complex.     

Offspring performance and female preference of Pagiophloeus tsushimanus (coleoptera: curculionidae) on three Lauraceae tree species: A potential risk of host shift caused by larval experience

The weevil Pagiophloeus tsushimanus Morimoto (Coleoptera: Curculionidae), native to Eastern Asia, is a wood-boring pest that causes severe damage to camphor trees (Cinnamomum sp.) in Shanghai, China. Other Lauraceae tree species that grew sympatrically with this pest in close proximity could face a potential threat. To assess the potential risks of host shift, we explored the phenotypic associations between preference and performance in P. tsushimanus reared on three Lauraceae tree species. In a no-choice experiment offering branches of each plant as diet material and oviposition sites, we found that individuals reared on Cinnamomum camphora (L.) Presl (Laurales: Lauraceae) exhibited the strongest performance with shorter development time, higher survival and growth rate in the immature stage, longer longevity and greater fecundity in adults. In contrast, those on novel Lauraceae tree species (Cinnamomum chekiangensis Nakai and Phoebe chekiangensis Shang) had difficulty completing their whole life cycle due to significantly lower survival and reproduction. In a multiple-choice experiment, C. camphora was established as the preferred host. However, we found that the larval experiences on the non-preferred host plants contributed to an increased preference for that plant species. These results indicated that both the preference-performance hypothesis and the Hopkins’ host selection principle are applicable in this weevil under experimental conditions. It is possible that although the weevil performed poorly on two novel Lauraceae tree species, under favourable conditions their surviving offspring could evolve into a new host-specific population. Consequently, this weevil pest needs to be monitored on these novel Lauraceae tree species.     

Chemical Diversity in the Genus Alpinia (Zingiberaceae): Comparative Composition of Four Alpinia Species Grown in Northern India

The essential‐oil compositions of leaves, flowers, and rhizomes of Alpinia galanga (L.) Willd ., Alpinia calcarata Rosc ., Alpinia speciosa K. Schum. , and Alpinia allughas Rosc . were examined and compared by capillary GC and GC/MS. Monoterpenoids were the major oil constituents identified. 1,8‐Cineole, α‐terpineol, (E)‐methyl cinnamate, camphor, terpinen‐4‐ol, and α‐ and β‐pinenes were the major constituents commonly distributed in leaf and flower essential oils. The presence of endo‐fenchyl acetate, exo‐fenchyl acetate, and endo‐fenchol was the unique feature of rhizome essential oils of A. galanga, A. calcarata, and A. speciosa. On contrary, the rhizome oil of A. allughas was dominated by β‐pinene. Significant qualitative and quantitative variations were observed in essential‐oil compositions of different parts of Alpinia species growing in subtemperate and subtropical regions of Northern India. Cluster analysis was performed to find similarities and differences in essential‐oil compositions based on representative molecular skeletons. Monoterpenoids, viz., 1,8‐cineole, terpinen‐4‐ol, camphor, pinenes, (E)‐methyl cinnamate, and fenchyl derivatives, were used as chemotaxonomic markers.     

Comparison of Chemical Composition of the Essential Oils from Different Botanical Organs of Pinus mugo Growing in Poland

The essential oils from needles, twigs, bark, wood, cones and young shoots of Pinus mugo were analyzed by GC, GC/MS, and ¹H‐NMR spectroscopy. More than 130 compounds were identified. The oils differed in the quantitative composition. The principal components of the oil from twigs with needles were 3‐carene (23.8 %), myrcene (22.3 %), and α‐pinene (10.3 %). The needle oil contained mainly α‐pinene (18.6 %), 3‐carene (11.3 %), and bornyl acetate (8.3 %). The oils from twigs without needles, young shoots, bark, and wood were dominated by 3‐carene (28.6 %, 15.0 %, 18.5 %, and 34.6 %, respectively) and myrcene (23.4 %, 24.0 %, 24.6 %, and 9.4 %, respectively). In the cone oil (E)‐β‐caryophyllene was the main constituent (24.0 %).     

Analysis of Chemical Composition and Assessment of Antioxidant,Cytotoxic and Synergistic Antibacterial Activities of Essential Oils from Different Plant Parts of Piper boehmeriifolium

The essential oils (EOs) from leaves, stems, and whole plant of Piper boehmeriifolium were analyzed using GC/FID and GC/MS. The main constituents of P. boehmeriifolium EOs were β‐caryophyllene, caryophyllene oxide, β‐elemene, spathulenol, germacrene D, β‐selinene, and neointermedeol. The antioxidant potential of the EOs were determined using DPPH^?, ABTS^?+ and FRAP assays. In ABTS^?+ assay, the leaf oil exhibited a remarkable activity with an IC₅₀ value of 7.36 μg/mL almost similar to BHT (4.06 μg/mL). Furthermore, the antibacterial activity of the oils as well as their synergistic potential with conventional antibiotics were evaluated using microdilution and Checkerboard assays. The results revealed that the oils from different parts of P. boehmeriifolium inhibited the growth of all tested bacteria and the minimum inhibitory concentrations were determined to be 0.078 – 1.250 mg/mL. In combination with chloramphenicol or streptomycin, the oils showed significant synergistic antibacterial effects in most cases. Besides, the results of MTT assay indicated that the oil of the whole plant exhibited significant cytotoxic activities on human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF‐7). In summary, the P. boehmeriifolium oils could be regarded as a prospective source for pharmacologically active compounds.     

Essential‐Oil Variability of Juniperus deltoides R.P.Adams along the East Adriatic Coast – How Many Chemotypes Are There?

The composition of the essential oils isolated from twigs of ten Juniperus deltoides R.P . Adams populations from the east Adriatic coast was determined by GC‐FID and GC/MS analyses. Altogether, 169 compounds were identified, representing 95.6–98.4% of the total oil composition. The oils were dominated by monoterpenes (average content of 61.6%), which are characteristic oil components of species of the Juniperus section. Two monoterpenes, α‐pinene and limonene, were the dominant constituents, comprising on average 46.78% of the essential oils. Statistical methods were deployed to determine the diversity of the terpene classes and the common terpenes between the investigated populations. These statistical analyses revealed the existence of three chemotypes within all populations, i.e., a α‐pinene, limonene, and limonene/α‐pinene type.     

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.