Terpenoid Composition Research Articles

Chemical Relationships between Liverworts of the Family Lejeuneaceae (Porellales, Jungermanniopsida)

The major purpose of this study was to determine the chemical relationships between liverwort species belonging to the Lejeuneaceae family on the basis of sesqui- and diterpenoid composition. GC/MS analysis of the 31 liverwort specimens belonging to the Lejeuneaceae family indicated variability of the chemical composition of terpenoids depending on liverwort species. Each of the analyzed liverworts is characterized by the presence of particular compounds. However, there are some characteristic components, which can be chemical markers of this liverwort family. These are the pinguisane and monocyclofarnesane type sesquiterpenoids, the fusicoccane type diterpenoids, and also the sesquiterpene hydrocarbon, isolepidozene. Chemical data also showed the differences among liverworts classified in the two subfamilies, the Ptychanthoideae and Lejeuneoideae. All of the mentioned characteristic components are present in species of the subfamily Ptychanthoideae. On the other hand, among the characteristic components, only beta-pinguisene was detected in Cololejeunea stotleriana, Colura irrorata, and Myriocoleopsis gymnocolea classified in the subfamily Lejeuneoideae (subtribe Cololejeuneinae). The latter component was found to be a marker for members of the subtribe Cololejeuneinae. Neither isolepidozene nor the pinguisanes, fusicoccanes and monocyclofarnesanes were found in Lejeunea topoensis (subfamily Lejeuneoideae). The existence of the chemical polymorphism between both subfamilies is also evident from PCA analysis.

Terpenoid composition and chemotaxonomic aspects of Miocene amber from the Koroglu Mountains, Turkey

A recently discovered fossil resin from Koroglu Mountain in Turkey has been analyzed by gas chromatography–mass spectrometry and pyrolysis gas chromatography–mass spectrometry to determine its structural class and botanical origin. The sesqui- and diterpenoids contained in the amber extract were used as chemosystematic markers when compared with terpenoids in extant conifers. The pyrolysis products were dominated by labdanoid derived bicyclic products together with succinic acid indicating Class Ia type amber. The biomarker compositions of the resin comprise mainly sesqui- and diterpenoids, and lack triterpenoids. This distribution suggests a gymnosperm, and more specifically a conifer source. The exclusive presence of abietane- and labdane-type diterpenoids together with the absence of phenolic diterpenoids strongly suggest that the resin was derived from Pinaceae. However, the presence of methyl-16,17-dinor callitrisate in the pyrolysate also suggests that Cupressaceae cannot be excluded as a possible source for the amber.

Differences in shoot and root terpenoid profiles and plant responses to fertilisation in Tanacetum vulgare

Intraspecific chemical diversity is a common phenomenon especially found in shoots of essential oil-accumulating plant species. Abiotic factors can influence the concentration of essential oils, but the effects are inconsistent and little is known in how far these may vary within an individual and within species between chemotypes. Tanacetum vulgare L. occurs in various chemotypes that differ in the composition of mono- and sesquiterpenoids in their shoot tissues. We investigated how far shoot chemotype grouping is mirrored in root terpenoid profiles. Furthermore, we studied whether different fertilisation amounts influence the plant growth and morphological traits as well as the constitutive terpenoid concentration of leaves and roots of three chemotypes, trans-carvyl acetate, β-thujone, and camphor, to different degrees. Shoot terpenoids were dominated by monoterpenoids, while the roots contained mainly sesquiterpenoids. The clear grouping in three chemotypes based on leaf chemistry was weakly mirrored in the root terpenoid composition. Furthermore, the leaf C/N ratio and the stem height differed between chemotypes. All plants responded to increased nutrient availability with increased total biomass and specific leaf area but decreased C/N and root/shoot ratios. Leaf terpenoid concentrations decreased with increasing fertiliser supply, independent of chemotype. In contrast to the leaves, the terpenoid concentrations of the roots were unaffected by fertilisation. Our results demonstrate that aboveground and belowground organs within a species can be under different selection pressures.

Steam volatile oil from Scutellaria repens Buch-Ham. ex D. Don; its composition and antibacterial activity

The terpenoid composition of steam volatile oil obtained from the aerial parts of Scutellaria repens Buch-Ham. ex D. Don (Lamiaceae) was analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). The oil was found to be rich in sesquiterpene hydrocarbons (77.5%); aromadendrene (30.7%) and β-funebrene (15.0%) were the principal constituents. Forty-four components were identified representing 90.8% of the oil. Antibacterial activity of the oil against ten bacterial strains was determined by measuring the inhibitory zone. The oil showed significant activity against Escherichia coli, Enterococcus faecalis and Klebsiella pneumoniae.

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%), β-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%), β-elemene (10; 0.2-2.4%), β-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.

Highly variable chemical signatures over short spatial distances among Scots pine (Pinus sylvestris) populations

Understanding within-species variability in terpenoid content and composition is highly relevant for predicting species adaptive potential to biotic stresses, but there is still limited information on terpene variations even for widespread species. We studied the foliage content and composition of terpenoids, foliage structure, and carbon (C) and nitrogen (N) contents in Pinus sylvestris L. in four Estonian sites ranging from dry forest to raised bog. In the bogs, samples were taken along the environmental gradient from drier margins towards wetter central parts. A chiral column was used to gain insight into the variation in terpene composition. We hypothesized that terpene contents increase and the composition becomes more diverse in more strongly N-limited sites (greater C/N ratio) and that terpene signatures cluster together in sub-sites with similar conditions (drier/wetter). Altogether 37 terpenes were quantified across the sites. Extremely large variability of terpene contents, 48-62% for monoterpenes and 61-89% for sesquiterpenes, was observed. According to the amounts of α-pinenes and (+)-3-carene, we distinguished two different 'pine chemotypes'. Contrary to the hypothesis, terpene contents and variability were the greatest in the dry site with the lowest C/N ratio. However, individual terpenoids correlated differently with C or N in different sites, indicating site effects on terpene composition. Moreover, correlations between the terpenoids and C or N depended on the pine chemotype. The sub-sites with different water regime were more strongly clustered together within the site than across the sites. The study demonstrates extensive variations in terpene contents and composition among the populations and over short spatial distances within the populations, suggesting a large among- and within-population adaptive capacity of P. sylvestris.

Volatile terpenoid compositions of leaf and rhizome of Curcuma amada Roxb. from Northern India

The volatile constituents of leaves and rhizomes of Curcuma amada grown in the foothills of Uttarakhand, India, were studied by using capillary gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS). The analysis revealed fifty-seven constituents comprising 92.69% and 98.56% of the leaf and rhizome oil compositions. The leaf essential oil of C. amada was mainly composed of furanosesquiterpenoids, namely epi-curzerenone (10.76%), curzerenone (9.53%), curzerene (3.95%) and furanogermenone (1.77%). Camphor (17.90%), isoborneol (7.30%), camphene (3.57%), borneol (1.87%) and camphene hydrate (1.25%) were the major constituents of 36.79% of the monoterpenoids fraction of leaf essential oil composition. Conversely, the rhizome essential oil of C. amada was mainly dominated by monoterpenoids (97.72%), with myrcene (88.84%) a single major constituent along with β-pinene (3.74%), (E)-β-ocimene (2.61%) and other minor constituents. Comparison of the volatile constituents of leaves and rhizome essential oil of C. amada revealed sharp qualitative and quantitative variations. Furanosesquiterpenoids, isoborneol and borneol were the exclusive constituents of leaf essential oil, and were not noticed in rhizome oil of C. amada. Myrcene, the single major constituent of rhizome oil, along with β-pinene and (E)-β-ocimene, seem to be responsible for the characteristic mango aroma of C. amada.

Exploring compositional diversity in the essential oils of 34 Ocimum taxa from Indian flora

To explore diversity in the morphological features, essential oil yield, and chemical composition of Ocimum taxa growing in foot and mid-hills of northern India; 34 populations representing five Ocimum species were collected and investigated. Essential oil yield (%v/w) was found to vary from 0.10 to 0.74% in different populations. Analyses of the essential oils by GC/FID and GC/MS and the subsequent classification by statistical analysis resulted in seven clusters with significant variations in their terpenoid compositions (cluster I: methyl chavicol/linalool; cluster II: eugenol/(Z)-β-ocimene/β-elemene/(E)-caryophyllene; cluster III: camphor/limonene; cluster IV: eugenol/(E)-caryophyllene/β-bisabolene/β-elemene/methyl chavicol/1,8-cineole; cluster V: linalool; cluster VI: methyl eugenol/(E)-caryophyllene/β-elemene; and cluster VII: citral/nerol/geraniol type). Comparison of present results with earlier reports revealed the existence of four new chemotypes in Ocimum taxa from this region.

Headspace solid‐phase microextraction combined with mass spectrometry as a powerful analytical tool for profiling the terpenoid metabolomic pattern of hop‐essential oil derived from Saaz variety

Hop (Humulus lupulus L., Cannabaceae family) is prized for its essential oil contents, used in beer production and, more recently, in biological and pharmacological applications. In this work, a method involving headspace solid-phase microextraction and gas chromatography-mass spectrometry was developed and optimized to establish the terpenoid (monoterpenes and sesquiterpenes) metabolomic pattern of hop-essential oil derived from Saaz variety as a mean to explore this matrix as a powerful biological source for newer, more selective, biodegradable and naturally produced antimicrobial and antioxidant compounds. Different parameters affecting terpenoid metabolites extraction by headspace solid-phase microextraction were considered and optimized: type of fiber coatings, extraction temperature, extraction time, ionic strength, and sample agitation. In the optimized method, analytes were extracted for 30 min at 40°C in the sample headspace with a 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane coating fiber. The methodology allowed the identification of a total of 27 terpenoid metabolites, representing 92.5% of the total Saaz hop-essential oil volatile terpenoid composition. The headspace composition was dominated by monoterpenes (56.1%, 13 compounds), sesquiterpenes (34.9%, 10), oxygenated monoterpenes (1.41%, 3), and hemiterpenes (0.04%, 1) some of which can probably contribute to the hop of Saaz variety aroma. Mass spectrometry analysis revealed that the main metabolites are the monoterpene β-myrcene (53.0 ± 1.1% of the total volatile fraction), and the cyclic sesquiterpenes, α-humulene (16.6 ± 0.8%), and β-caryophyllene (14.7 ± 0.4%), which together represent about 80% of the total volatile fraction from the hop-essential oil. These findings suggest that this matrix can be explored as a powerful biosource of terpenoid metabolites.

Phytochemical analysis of the leaf volatile oil of walnut tree (Juglans regia L.) from western Himalaya

The walnut tree (Juglans regia L.), commonly known as ‘Akhrot’ in India, is a valuable tree has a long history of medicinal use to treat a wide range of health complaints. To explore the diversity in essential oil yield and composition of J. regia, leaves were collected during spring season from 28 populations growing in western Himalaya. Comparative results showed considerable variations in the essential oil yield and composition of J. regia leaves. The essential oil yield varied from 0.02% to 0.12% in fresh leaves of the different populations of J. regia. Analysis of the essential oils by GC/FID and GC/MS and the subsequent classification by statistical analysis resulted in three clusters with significant variations in their terpenoid composition. Altogether, 70 constituents, representing 83.2–98.0% of the total oil composition, were identified and quantified. Major components of the essential oils were (E)-caryophyllene (1.4–47.9%), β-pinene (4.5–39.5%), germacrene D (5.0–23.3%), α-pinene (1.5–18.1%), α-humulene (1.1–11.8%), α-zingiberene (0.1–11.3%), α-copaene (0.0–10.1%), limonene (0.8–8.6%), caryophyllene oxide (0.1–8.6%), ar-curcumene (0.0–7.2%), δ-cadinene (0.3–6.7%), (E)-β-farnesene (0.0–5.9%), 1,8-cineole (<0.0–5.4%), γ-curcumene (0.0–4.2%), and methyl salicylate (0.1–4.0%). This is the first report on leaf volatile oil composition of J. regia populations from western Himalaya. Out of the 70 identified constituents, over 25 were described for the first time for J. regia.

Antioxidant and antibacterial activities of the leaf essential oil and its constituents furanodienone and curzerenone from Lindera pulcherrima (Nees.) Benth. ex hook. f.

Background:Lindera pulcherrima (Nees.) Benth. ex Hook. f. (Family: Lauraceae), an evergreen shrub, is an important medicinal plant distributed in temperate Himalayan regions. The leaves and bark are used as spice in cold, fever, and cough.Materials and Methods:In this study, the terpenoid composition, antioxidant, and antibacterial activities of the leaf essential oil and its major constituents are being analyzed.Conclusion:The in vitro antioxidant activity showed a potent free radical scavenging activity for the essential oil as evidenced by a low IC50 value for DPPH radical followed by furanodienone (0.087 ± 0.03 and 1.164 ± 0.58 mg/ml respectively) and the inhibition of lipid peroxidation for the oil and furanodienone also followed the same order (IC50 0.74 ± 0.13 and 2.12 ± 0.49 mg/ml, respectively). The oil and the constituents were also tested against three Gram negative (Escherichia coli, Salmonella enterica enterica, and (Pasturella multocida) and one Gram positive (Staphylococcus aureus) bacteria. The essential oil was effective against S. aureus (IZ = 19.0 ± 0.34; MIC 3.90 μl/ml) while furanodienone showed potent activity against E. coli and S. enterica enterica (IZ = 18.0 ± 0.14 and 16.0 ± 0.10 respectively). On the other hand, curzerenone was found to be slightly effective against E. coli (IZ = 10.8 ± 0.52). The MIC value of the essential oil was least against S. aureus (MIC = 3.90 μl/ml) and that of furanodienone against E. coli (MIC = 3.90 μl/ml).

Chemical Diversity in the Essential Oil of Indian Valerian (Valeriana jatamansiJones)

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 β-gurjunene (7; 0.0-7.1%). V. jatamansi populations with contents of 1 higher than 60% may be utilized commercially in perfumery.

Terpenoid composition and antifungal activity of three commercially important essential oils against Aspergillus flavus and Aspergillus niger

Hydro-distilled essential oils extracted from three commercially important aromatic plants were analysed by capillary gas chromatography-flame ionization detector and gas chromatography/quadrupole mass spectrometry and subjected to antifungal activity. Fifteen compounds, which accounted for 97.8% of Acorus calamus root oil composition have been identified. Besides the major constituent (Z)-asarone (81.1–92.4%), (Z)-methyl isoeugenol (1.8–2.1%), (Z)-isoelemicin (1.2–1.3%), (E)-asarone (1.0–2.6%), (E)-methyl isoeugenol (0.2–0.4%), (Z)-β-ocimene (0.2–0.4%), elemicin (0.2–0.3%), linalool (0.1–0.9%) and kessane (t–0.2%) were identified. Monoterpenes constituted the main fraction of Origanum vulgare essential oil attaining 90.5% of the total oil composition. p-Cymene (10.3%) was the major component of the monoterpene hydrocarbon fraction while thymol (53.2%) and carvacrol (3.9%) were the most abundant oxygenated monoterpenes among the 33 identified constituents. Cinnamomum tamala leaf oil contained (E)-cinnamaldehyde as the principal component. Quantitative variations in (Z)-cinnamaldehyde (5.8–7.1%), linalool (6.4–8.5%) and (E)-cinnamyl acetate (4.7–5.2%) were significant. The antifungal activity of the hydro-distilled essential oils of A. calamus, O. vulgare and C. tamala were evaluated against Aspergillus flavus and Aspergillus niger. Disc diffusion method was used for the determination of the inhibitory effect. O. vulgare essential oil exhibited the highest activity. Moreover, all three essential oils inhibit the growth of A. flavus and A. niger.

Inter-Population Variability of Terpenoid Composition in Leaves of Pistacia lentiscus L. from Algeria: A Chemoecological Approach

Three different altitudes were selected to study the variability of terpenoid composition from leaves of female plants of Pistacia lentiscus L. throughout the elevation gradient. GC-MS analyses showed that terpenoid contents change with altitude. Forty nine compounds were identified with a high interpopulation variability for low- and midaltitude sites that also exhibited the same major components when data were expressed on dry weight basis. However, Two-Way-ANOVA followed by Tukey’s post hoc test showed that monoterpene hydrocarbons increased with elevation, giving values of 21.7, 37.5 and 221.5 µg g−1 dw for low- mid- and highlands, respectively. On the other hand, applying P.C.A. with data expressed in percentage of the chromatogram of the volatile extract led to the identification of three chemotypes associated with altitudinal levels. In highlands (Group I), the major compounds were β-caryophyllene (12%), δ-cadinene (9.3%) and α-pinene (6.3%) while in midlands (Group II), β-caryophyllene (11.5%), δ-cadinene (8.6%) and caryophyllene oxide (6.8%) were the main components. In lowlands (Group III) δ-cadinene (10.9%), cubebol (10.5%) and β-bisabolene (7.7%) were chiefly present. Hence, the involvement of genetic factors, temperature and drought in the chemical polymorphism of P. lentiscus associated with elevation is discussed in this report.

Variability in Volatile Terpenoid Compositions of Peppermint Cultivars and Some Wild Accession from Northern India

The terpenoid composition of different cultivars of peppermint (Mentha piperita L.) grown in Uttarakhand (India) and accessions collected from wild were analyzed by capillary GC and GC/MS. The major characteristic constituents of all the cultivars and wild accessions were menthol (30.3–47.8%), menthone (4.5–48.6%), menthyl acetate (1.0–9.5%), menthofuran (0.1–14.6%), 1,8-cineole (4.1–8.9%), neo-menthol (1.5–4.9%) and iso-menthone (1.2–3.9%). Although the major characteristic constituents were the same in all oils, there were considerable variations in their quantitative makeup. The contents of menthol and menthofuran were found relatively higher in all cultivars grown in foothills compared to mid-hills. Interestingly, menthofuran, a characteristic compound of the peppermint oil, was detected either at trace level or as a minor component in all the three wild accessions collected from mid-hills. Quality evaluation of peppermint oils revealed that the performance of cultivars grown at foothill conditions are very close to the requirements of European pharmacopoeia as compared to mid-hills.

Terpenoid Composition and Antibacterial Activity of Essential oil from Salvia hians Royle ex. Benth

Salvia hians Royle ex. Benth (Lamiaceae) growing wild in the central Himalayan region, was analyzed by capillary GC and GC-MS. The oil was found to be rich in sesquiterpine hydrocarbons (52.5 %). Total 64 compounds were identified representing 94.9 % of the oil; γ-cadinene (10.9 %), δ-cadinene (9.2 %), caryophyllene acetate (9.7 %) and cubenol (6.1 %) were found to be the principal constituents. The oil was tested against ten bacterial strains and showed significant activity against Klebsiella pneumoniae, Bacillus subtilis and Agrobacterium tumefaciens.

Terpenoid Compositions and Antioxidant Activities of Two Indian Valerian Oils from the Khasi Hills of North-east India

The volatile constituents of Valeriana jatamansi Jones and V. hardwickii Wall. (Valerianaceae) collected from the Khasi Hills of north-east India were analyzed by GC and GC/MS. Twenty-seven and twenty-one compounds were characterized and identified from V. jatamansi and V. hardwickii samples, representing 90.6% and 82.7% of the total oil, respectively. Sesquiterpenes were shown to be the main constituents in both the oil samples. Maaliol (26.1%), patchouli alcohol (9.3%) and a-gurjunene (8.7%) were the major components of V. jatamansi oil, whereas valeracetate (21.3%), methyl linoleate (14.1%), bornyl acetate (13.8%) and cuparene (7.1%) were the main constituents of V. hardwickii oil. Both Indian valerian essential oils were studied for their antioxidant activities using the free radical-scavanging activity (DPPH) and ferric reducing antioxidant power (FRAP) assays. V. hardwickii oil exhibited a higher antioxidant capacity than V. jatamansi in both assays. For both the valerian oil samples, there was a concentration-dependent increase in free radical scavenging activity and ferric reducing capacity. Both valerian oils and their ingredients are potential sources of natural antioxidants.

Terpenoid Composition and Antimicrobial Activity of the Essential Oil from Salvia nubicola Wall ex Sweet.

The essential oil of Salvia nubicola Wall ex Sweet. (Lamiaceae) was analyzed by GC and GC/MS. Sixty-four compounds were identified, constituting 94.0% of the oil. The oil was found rich in sesquiterpene hydrocarbons (73.3%). Germacrene D (46.2%) was the principal constituent. Oxygenated sesquiterpenes constituted 12.3% of the oil. The oil showed activity against tested bacterial and fungal strains used, and which was found comparable with the standard antibiotics (Ampicillin, Erythromycin and Clotrimazole) used for comparison.

Terpenoid Compositions and Enantio-differentiation of Linalool and Sclareol in Salvia sclarea L. from Three Different Climatic Regions in India

Salvia sclarea L. essential oil samples collected from three different climatic regions viz., Kashmir, Uttarakhand and Uttar Pradesh in India have been analyzed by capillary GC, enantio-GC and GC/MS. Linalool (23.6%), α-terpineol (3.8%), linalyl acetate (51.2%), β-caryophyllene (3.2%), germacrene D (1.3%) and sclareol (1.3%) were recorded in the oil S. sclarea cultivated in Lucknow UP while the Kashmir oil sample possessed the highest percentage of linalyl acetate (60.8%) and lowest linalool (14.5%) along with α-terpineol (1.8%), geranyl acetate (2.2%), β-caryophyllene (1.9%), germacrene D (2.6%) and sclareol (1.3%) as the other minor constituents. In contrast, the oil of S. sclarea from Purara in Uttarakhand showed highest percentage of linalool (29.8%), α-terpineol (5.3%) and sclareol (2.3%) and the lowest linalyl acetate (45.7%) among all the three samples. Further, high enantiomeric ratios ranged 76.8–79.5% for 3R-(-)-linalool and 78.8–99% for (-)-sclareol were determined on BETA DEX 110 capillary column.

Chemical composition and palaeobotanical origin of Miocene resins from Kerala-Konkan Coast, western India

The terpenoid composition of resins from the Miocene lignite horizons from the Kerala-Konkan Coast, western India was analyzed by Curie-point pyrolysis-gas chromatography-mass spectrometry (Cupy-GC-MS). The major pyrolysates were cadalene-based bicyclic sesquiterpenoids including some C30-C31 bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family. These plants are typically supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period. The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch. These sesquiterpenoids which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in the western Indian region.