Population Genetics Coupled Chemical Profiling for Conservation Implications of Decalepis salicifolia (Bedd. ex Hook.f.) Venter, an Endemic and Critically Endangered Species of Western Ghats, India.

Information on the genetic diversity and population structure is essential for developing conservational management programs, especially for threatened species. Decalepis salicifolia (Bedd. ex Hook.f.) Venter is a steno-endemic and critically endangered species of the south Western Ghats of India. The present study used ISSR markers as well as essential oil profiling to reveal the extent and distribution of genetic as well as the chemical diversity of all the twelve known populations of D. salicifolia. A total of 84 amplicons generated using 17 ISSR primers represented an overall 72.34% polymorphism. The highest percentage of polymorphic loci was recorded in the population of Theemalai (40.48%) and lowest in Kokanmalai (4.76%) with an average of 20.04% across all the studied populations. At the species level, the Nei's genetic diversity observed was 0.255 ± 0.186, while Shannon's information index observed was 0.385 ± 0.260. The genetic similarity-based unweighted pair-group method with arithmetic average dendrogram grouped the populations according to their geographic locations, which was corroborated by principal component analysis and Bayesian clustering. Distribution of genetic variance through analysis of molecular variance indicated that 38% variance resides within the population, and 62% variance resides among the populations (P < 0.001). Gas chromatography analyses of root volatiles showed significant variation in the percent content of 2-hydroxy-4-methoxybenzaldehyde. The Mantel test analyses showed a positive correlation between the genetic versus geographic distances. Based on the results, both ex situ and in situ conservation strategies are suggested to maximally preserve the genetic resources of this endangered species.

Chemical composition and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of cassumunar-ginger.

BACKGROUND: Zingiber montanum (J.Koenig) Link ex A.Dietr. (Zingiberaceae), commonly known as cassumunar-ginger, is a folk remedy for the treatment of inflammations, sprains, rheumatism and asthma. The aim of the present study was to assess the chemical composition, and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of the essential oil of Z. montanum originating from India. RESULTS: The hydrodistilled essential oil of Z. montanum rhizome was analyzed using gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. A total of 49 constituents, forming 98.7-99.9% of the total oil compositions, was identified. The essential oil was characterized by higher amount of monoterpene hydrocarbons (32.6-43.5%), phenylbutanoids (27.5-41.2%) and oxygenated monoterpenes (11.4-34.1%). Major constituents of the oil were sabinene (13.5-38.0%), (E)-1-(3',4'-dimethoxyphenyl)buta-1,3-diene (DMPBD) (20.6-35.3%), terpinen-4-ol (9.0-31.3%), γ-terpinene (1.1-4.8%) and ß-phellandrene (1.0-4.4%). The oil was evaluated against eight pathogenic bacteria and two fungal strains. It exhibited low to good antibacterial activity (minimum inhibitory concentration: 125-500 µg mL-1 ) and moderate antifungal activity (250 µg mL-1 ) against the tested strains. The oil reduced germination (69.8%) and inhibited the root and shoot growth of lettuce significantly (LD50 : 3.58 µL plate-1 ). However, it did not demonstrate acetylcholinesterase inhibitory activity up to a concentration of 10 mg mL-1 . CONCLUSIONS: The essential oil of Z. montanum can be used as a potential source of DMPBD, terpinen-4-ol and sabinene for pharmaceutical products. The results of the present study add significant information to the pharmacological activity of Z. montanum native to India. © 2017 Society of Chemical Industry.

Chemical Composition and Allelopathic, Antibacterial, Antifungal, and Antiacetylcholinesterase Activity of Fish-mint (Houttuynia cordataThunb.) from India.

Fish-mint (Houttuynia cordataThunb.), belonging to family Saururaceae, has long been used as food and traditional herbal medicine. The present study was framed to assess the changes occurring in the essential-oil composition of H. cordata during annual growth and to evaluate allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities. The essential-oil content ranged from 0.06 - 0.14% and 0.08 - 0.16% in aerial parts and underground stem, respectively. The essential oils were analysed by GC-FID, GC/MS, and NMR (1 H and 13 C). Major constituents of aerial-parts oil was 2-undecanone (19.4 - 56.3%), myrcene (2.6 - 44.3%), ethyl decanoate (0.0 - 10.6%), ethyl dodecanoate (1.1 - 8.6%), 2-tridecanone (0.5 - 8.3%), and decanal (1.1 - 6.9%). However, major constituents of underground-stem oil were 2-undecanone (29.5 - 42.3%), myrcene (14.4 - 20.8%), sabinene (6.0 - 11.1%), 2-tridecanone (1.8 - 10.5%), ß-pinene (5.3 - 10.0%), and ethyl dodecanoate (0.8 - 7.3%). Cluster analysis revealed that essential-oil composition varied substantially due to the plant parts and season of collection. The oils exhibited significant allelopathic (inhibition: 77.8 - 88.8%; LD50 : 2.45 - 3.05 µl/plate), antibacterial (MIC: 0.52 - 2.08 µl/ml; MBC: bacteriostatic) and antifungal (MIC: 2.08 - 33.33 µl/ml; MFC: 4.16 - 33.33 µl/ml) activities. The results indicate that the essential oil from H. cordata has a significant potential to allow future exploration and exploitation as a natural antimicrobial and allelopathic agent.

Essential oil composition of Aegle marmelos (L.) Correa: chemotypic and seasonal variations.

BACKGROUND: Aegle marmelos (L.) Correa is a sacred medicinal and nutraceutical tree of India. The present study planned to explore the chemotypic and seasonal variability of the leaf essential oil of A. marmelos from north India for proper industrial utilization. RESULTS: The essential oil yield varied from 0.37% to 0.80% in leaves of A. marmelos populations. Analysis of the essential oils by gas chromatography and gas chromatography-mass spectrometry, and the subsequent classification by statistical analysis showed three types of chemical compositions for A. marmelos with significant variations in their terpenoid compositions. Major components of the essential oils were limonene (31.0-90.3%), α-phellandrene (<0.05-43.5%), (E)-ß-ocimene (0.7-7.9%), α-pinene (<0.05-7.5%), (E)-caryophyllene (0.5-5.3%), ß-elemene (<0.05-4.2%) and germacrene B (0.0-3.3%). In addition to this, essential oil of a locally growing A. marmelos population was also investigated for seasonal variations. The essential oil yield in this population varied from 0.37% to 0.82% during different seasons. Major constituents, namely α-phellandrene (35.8-49.8%), limonene (24.7-34.3%), (E)-ß-ocimene (4.2-10.0%) and α-pinene (6.0-8.0%), showed considerable variations due to season of collection. CONCLUSIONS: The growing location and harvesting season had a close relation to yield and quality of A. marmelos leaf essential oil. The results obtained are of significance for determining a suitable time for harvesting A. marmelos leaves.

Phytochemical diversity of Murraya koenigii (L.) Spreng. from Western Himalaya.

Murraya koenigii (L.) Spreng. (Rutaceae), commonly known as 'curry leaf tree', is a popular spice and condiment of India. To explore the diversity of the essential-oil yield and aroma profile of curry leaf, growing wild in foot and mid hills of north India, 58 populations were collected during spring season. M. koenigii populations were found to grow up to an altitude of 1487 m in north India. Comparative results showed considerable variations in the essential-oil yield and composition. The essential-oil yield varied from 0.14 to 0.80% in shade-dried leaves of different populations of M. koenigii. Analysis of the essential oils by GC and GC/MS, and the subsequent classification by statistical analysis resulted in four clusters with significant variations in their terpenoid composition. Major components of the essential oils of investigated populations were α-pinene (2; 4.5-71.5%), sabinene (3; <0.05-66.1%), (E)-caryophyllene (11; 1.6-18.0%), ß-pinene (4; <0.05-13.6%), terpinen-4-ol (9; 0.0-8.4%), γ-terpinene (8; 0.2-7.4%), limonene (7; 1.1-5.5%), α-terpinene (6; 0.0-4.5%), (E)-nerolidol (14; 0.0-4.1%), α-humulene (12; 0.6-3.5%), α-thujene (1; 0.0-2.5%), ß-elemene (10; 0.2-2.4%), ß-selinene (13; 0.2-2.3%), and myrcene (5; 0.5-2.1%). Comparison of the present results with those in earlier reports revealed new chemotypes of M. koenigii in investigated populations from Western Himalaya. The present study documents M. koenigii populations having higher amounts of sabinene (3; up to 66.1%) for the first time.

Chemical diversity in the essential oil of Indian valerian (Valeriana jatamansi Jones).

To explore the diversity in the essential oil yield and composition of Valeriana jatamansi Jones (syn. V. wallichii DC) growing wild in Uttarakhand (Western Himalaya), 17 populations were collected from different locations and grown under similar conditions. Comparative results showed considerable variations in the essential oil yield and composition. The essential oil yield varied from 0.21 to 0.46% in the fresh roots and rhizomes of different populations of V. jatamansi. Analysis of the essential oils by GC (RI) and GC/MS and the subsequent classification by principal component analysis (PCA) resulted in six clusters with significant variations in their terpenoid composition. Major components in the essential oils of the different populations were patchouli alcohol (1; 13.4-66.7%), α-bulnesene (3; <0.05-23.5%), α-guaiene (4; 0.2-13.3%), guaiol (5; <0.05-12.2%), seychellene (6; 0.2-9.9%) viridiflorol (<0.05-7.3%), and ß-gurjunene (7; 0.0-7.1%). V. jatamansi populations with contents of 1 higher than 60% may be utilized commercially in perfumery.

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, alpha-terpineol, (E)-methyl cinnamate, camphor, terpinen-4-ol, and alpha- and beta-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 beta-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.

Chemical diversity in Indian oregano (Origanum vulgare L.).

The terpenoid composition of the essential oils of 17 different populations of Origanum vulgare L., collected from wild populations and subsequently grown under similar conditions in the sub-temperate region of the Western Himalaya, was studied. Analysis by GC (RI) and GC/MS allowed the identification of 51 components, representing 90.15 to 99.94% of the total oil. The two classes of the phenolic compounds and the monoterpenoids were predominant in all the essential oils. On the basis of the major constituents, i.e., marker compounds, and by comparison of the results with previous reports, new chemotypes could be identified. Principal component analysis was performed to determine the chemical variability within the different populations of O. vulgare collected and grown under similar conditions. Based on the marker compounds, six chemotypes with significant variations in their terpenoid profile were noticed within the 17 populations.

Compositional and Enantiomeric Analysis of the Essential Oil of Taxodium distichum from India.

The leaf essential oil composition of Taxodium distichum L., collected from the foothills of Uttarakhand, India was analyzed using gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) equipped with DB-5 (5% diphenyl-95% dimethyl polysiloxane) and ß-cyclodextrin (6-tertiarybutyldimethylsiliyl-2,3-diethyl-ß-cyclodextrin) capillary columns. Seventeen constituents, representing 90.3 to 99.4% of composition were identified in the essential oils from different seasons, viz. spring, summer, rainy, autumn and winter. The essential oil composition was mainly dominated by monoterpene hydrocarbons, represented mainly by α-pinene (81.9-94.3%). Other constituents of the oil were myrcene (0.5-4.7%), ß-pinene (2.2-2.9%), limonene (0.5-1.5%), camphene (≤ 0.03-1.5%), and α-terpineol (upto 1.6%). Chiral analysis of T. distichum essential oil on an ethyl substituted ß-cyclodextrin capillary column revealed the presence of a-pinene in racemic form, with an enantiomeric ratio of 49.3% for (1R)-(+)- and 50.7% for (1S)-(-)-α-pinene.

Chemical analysis of volatile oils from West Himalayan Pindrow Fir Abies pindrow.

The essential oil composition of needle and stem oils of Abies pindrow (Royle ex D.Don) Royle, commonly known as Pindrow or West Himalayan Fir, were analyzed by gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Fifty-six constituents, accounting for 96.0% of needle and 83.5% of stem oil composition, were identified. The oils were characterized by a high content of monoterpenoids (68.9%-79.9%), mainly comprised by limonene (21.0%-34.4%), camphene (0.5%-19.9%), alpha-pinene (13.8%-16.8%), myrcene (6.7%-8.3%) and beta-pinene (6.5%-8.6%). Monoterpene hydrocarbons were predominant in both oils, but the quantitative and qualitative composition of the volatile constituents was specific for each part of the tree; and considerable variations in their terpenoid production pattern were also noticed. Results were compared with earlier reported fir species from different geographic regions.

Chemical composition of root aroma of Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter, an endemic and endangered ethnomedicinal plant from Western Ghats, India.

Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter, which belongs to the family Apocynaceae, is a perennial under shrub, endemic to southern Western Ghats, India. The highly aromatic tuberous roots of the D. arayalpathra are used as an effective remedy for peptic ulcer, cancer-like afflictions and as rejuvenating tonic by native tribes. The objective of this study was to characterise the root aroma of D. arayalpathra for possible industrial applications. Hydrodistilled volatile oil of the roots was analysed by gas chromatography-flame ionisation detector and gas chromatography-mass spectrometry. The volatile oil was characterised by the presence of higher amount of an industrially important flavour molecule, 2-hydroxy-4-methoxybenzaldehyde (96.8%) along with some other minor or trace constituents. Owing to characteristic vanillin-like flavour, the root oil of the D. arayalpathra can be explored as a potential substitute of vanillin-aroma in the flavour industry.

Compositional variability and antifungal potentials of ocimum basilicum, O. tenuiflorum, O. gratissimum and O. kilimandscharicum essential oils against Rhizoctonia solani and Choanephora cucurbitarum.

The composition of hydrodistilled essential oils of Ocimum basilicum L. (four chemovariants), O. tenuiflorum L., O. gratissimum L., and O. kilimandscharicum Guerke were analyzed and compared by using capillary gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS). Phenyl propanoids (upto 87.0%) and monoterpenoids (upto 83.3%) were prevalent constituents distributed in the studied Ocimum taxa. The major constituents of the four distinct chemovariants of O. basilicum were methyl chavicol (86.3%), methyl chavicol (61.5%)/linalool (28.6%), citral (65.9%); and linalool (36.1%)/citral (28.8%). Eugenol (66.5% and 78.0%) was the major constituent of O. tenuiflorum and O. gratissimum. Eugenol (34.0%), ß-bisabolene (15.4%), (E)-α-bisabolene (10.9%), methyl chavicol (10.2%) and 1,8-cineole (8.2%) were the major constituents of O. kilimandscharicum. In order to explore the potential for industrial use, the extracted essential oils were assessed for their antifungal potential through poison food technique against two phytopathogens, Rhizoctonia solani and Choanephora cucurbitarum, which cause root and wet rot diseases in various crops. O. tenuiflorum, O. gratissimum, and O. kilimandscharicum exhibited complete growth inhibition against R. solani and C. cucurbitarum after 24 and 48 h of treatment. O. basilicum chemotypes showed variable levels of growth inhibition (63.0%-100%) against these two phytopathogens.

Fragrant volatile oil composition of Nutmeg Geranium (Pelargonium × fragrans Willd.) from India.

Hydrodistilled essential oil of 'Nutmeg Geranium' (Pelargonium × fragrans Willd.), grown in foothills of northern India was analysed by capillary gas chromatography (GC/flame ionisation detector (FID)) and GC-mass spectrometry (GC/MS). A total of 51 constituents, representing 90.2% of the total oil composition were identified. The oil was mainly dominated by monoterpenoids (58.4%), followed by sesquiterpenoids (19.4%), and phenyl propanoids (10.1%). Major constituents of the essential oil were fenchone (10.7%), methyl eugenol (9.9%), α-pinene (9.4%), α-thujene (7.6%), limonene (6.4%), spathulenol (4.7%), sabinene (4.3%), linalool (4.2%), (E)-caryophyllene (4.2%), terpinen-4-ol (3.2%), ß-pinene (2.9%), caryophyllene oxide (2.2%) and bicyclogermacrene (2.1%). This is the first report on essential oil composition of Nutmeg Geranium oil grown in India.

Chemical composition of leaf and root essential oils of Boenninghausenia albiflora Reichb. from northern India.

The leaf and root essential oil composition of Boenninghausenia albiflora Reichb and Meissner (family: Rutaceae), collected from Uttarakhand, India, was analysed by capillary gas chromatography and gas chromatography-mass spectrometry. The major constituents identified in the leaf essential oil were ß-myrcene, (Z)-ß-guaiene, (Z)-ß-ocimene and ß-caryophyllene, whereas bicyclogermacrene, α-terpinyl acetate, geijerene and ß-copaene-4α-ol were identified as the major constituents of the root essential oil. This is the first time that the chemical compositions of leaf and root essential oils of B. albiflora have been investigated in detail. The results show significant qualitative and quantitative variations in leaf and root oil composition.

Variation in the volatile constituents of different plant parts of Ligusticopsis wallichiana from western Himalaya, India.

The essential oil composition of the leaves, stem, flowers and roots of Ligusticopsis wallichiana (DC.) Pimenov & Kljuykov were analyzed by GC-FID and GC-MS methods. Forty-five constituents, forming 93.2%-97.8% of the oil compositions, were dominated by acetylenic (31.5%-92.8%) compounds and sesquiterpenoids (0.3%-44.4%). The leaf essential oil was mainly composed 3,5-nonadiyne (35.8%), beta-selinene (20.9%), alpha-funebrene (10.1%) and (Z)-falcarinol (6.1%). The stem oil was dominated by acetylenic compounds (73.8%) represented by 3,5-nonadiyne (67.8%) and (Z)-falcarinol (5.7%). On the contrary, the major components of the flower essential oil were sesquiterpenoids (37.5%), such as germacrene D (16.6%), alpha-funebrene (7.4%), and acetylenic compounds (31.5%), such as (Z)-falcarinol (21.0%) and 3,5-nonadiyne (10.0%). Monoterpenoids constituted 23.9% of the flower oil with limonene (19.9%) as the single major constituent. The essential oil of the roots was dominated by 3,5-nonadiyne (90.5%). The results showed considerable qualitative and quantitative variations in the essential oil compositions of the different plant parts of L. wallichiana. (Z)-Falcarinol (1.9%-21.0%) and alpha-funebrene (0.1%-10.1%) were reported for the first time from the essential oils of L. wallichiana.

Chemical composition and antimicrobial activity of the inflorescence essential oil of Capillipedium parviflorum (R. Br.) Stapf. from India.

Essential oil isolated from the inflorescences of Capillipedium parviflorum (R. Br.) Stapf., collected from Kumaon region of Western Himalaya, India, was investigated by GC and GC-MS. A total of 45 constituents representing 99.0% of the essential oil were identified. The major components of this oil were 4-undecanone (33.2%), 4-undecanol (29.7%), 4-nonanol (13.9%), α-muurolol (5.3%), 4-tridecanone (3.6%), methyl-2-oxo-nonanoate (3.1%), trans-2-hexenyl butanoate (1.1%) and 1-tetradecanol (1.0%). The antimicrobial activity of the essential oil was determined against eight Gram-positive and Gram-negative bacterial strains, as well as two fungal strains. The bioassay showed that the essential oil possessed good antibacterial activity.

Comparative volatile oil composition of four Ocimum species from northern India.

The hydrodistilled essential oils of Ocimum basilicum L. cvs. 'Vikarsudha' and 'CIM-Soumya', Ocimum sanctum L. cvs. 'Green' (CIM-Ayu) and 'Purple', Ocimum gratissimum L. and Ocimum kilimandscharicum Guerke have been studied by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Phenylpropanoids (65.2-77.6%) constituted the major proportion of the essential oil compositions of O. sanctum, O. basilicum and O. gratissimum, whilst oxygenated monoterpenes (72.7%) constituted the major proportion of the oil composition of O. kilimandscharicum. The essential oil compositions of cvs. 'Green' and 'Purple' of O. sanctum were almost the same, and both cultivars were dominated by eugenol (67.4% and 72.8%), ß-elemene (11.0% and 10.9%), ß-caryophyllene (7.3% and 8.4%) and germacrene D (2.4% and 2.2%), whilst the major components in O. basilicum cvs. 'Vikarsudha' and 'CIM-Soumya' were methyl chavicol (68.0% and 64.9%) and linalool (21.9% and 25.6%), along with bicyclogermacrene (2.0% and 0.7%) and α-terpineol (1.2% and 0.1%). Eugenol (77.2%), 1,8-cineole (7.6%), germacrene D (2.7%) and ß-caryophyllene (1.7%) were identified as the major constituents of O. gratissimum. On the contrary, the essential oil from O. kilimandscharicum was mainly dominated by monoterpenoids (95.8%), represented by camphor (64.9%), limonene (8.7%), camphene (6.4%) and (E)-ß-ocimene (3.0%).

Comparative study of volatile oil compositions of two Plectranthus species from northern India.

The leaf and inflorescence essential oils of Plectranthus rugosus Wall. (syn. Rabdosia rugosa Wall.) and Plectranthus incanus L. (syn. Plectranthus mollis L.), which grow wild in Uttarakhand, India, were analysed and compared by capillary gas chromatography and gas chromatography-mass spectrometry. The analysis led to the identification of 43 constituents, forming 89.5-93.6% of the total oil compositions. Both leaf and inflorescence oil of P. rugosus were dominated by sesquiterpene hydrocarbons (71.8%, 71.7%) represented by ß-caryophyllene (36.2%, 29.8%), germacrene D (25.2%, 28.2%) and α-humulene (6.6%, 8.6%) as the major constituents. Conversely, the leaf and inflorescence oil of P. incanus were dominated by monoterpenoids (74.4%, 65.8%) with piperitenone oxide (44.2%, 38.5%), piperitone (8.6%, 12.2%) and terpinolene (14.5%, 10.2%) as major constituents. Piperitenone oxide, piperitone, cis- and trans-piperitols and trans-piperitol acetate were the marker constituents in P. incanus, which were not noted in the essential oil of P. rugosus.

Variation in the volatile constituents of Artemisia annua var. CIM-Arogya during plant ontogeny.

The essential oils yield and composition of the aerial parts of A. annua var. CIM-Arogya grown in Uttarakhand, India were analyzed and compared by capillary GC and GC-MS at different stages of development. The analysis led to the identification of 81 constituents forming 91.0%-97.1% of the essential oils compositions. The essential oil content of the aerial parts was found to vary from 0.3% to 0.7% at different stages of growth. A. annua crop harvested at full flowering and seed setting stage gave higher yield of essential oil (0.6%, 0.7%) than that harvested at pre flowering (0.5%), late vegetative (0.4%, 0.5%), mid vegetative (0.4%, 0.4%) and early vegetative stages (0.3%, 0.3%). The essential oils at different stages of growth showed monoterpenoids (38.5%-72.0%) and sesquiterpenoids (22.2%-48.2%) as major grouped constituents. The major constituents identified were camphor (22.8%-42.6%), 1,8-cineole (3.7%-8.4%), linalool (<0.1%-11.9%), beta-caryophyllene (2.0%-9.2%), (E)-beta-farnesene (1.3%-8.5%), germacrene D (0.5%-7.3%) and 1-epi-cubenol (0.7%-5.2%) in essential oil samples collected at different crop stages.

Essential oil composition of Thymus serpyllum cultivated in the Kumaon region of western Himalaya, India.

The hydrodistilled essential oil of aerial parts of Thymus serpyllum L. (Lamiaceae), cultivated in the Kumaon region of western Himalaya was analyzed by GC and GC-MS. Twenty-nine compounds, representing 91.8% of the oil, were identified. The major components were thymol (58.8%), p-cymene (5.7%), thymol methyl ether (4.0%), borneol (3.8%), sabinene (3.4%), gamma-terpinene (3.4%) and carvacrol methyl ether (3.2%).