Research Article Received: 19 July 2013 Revised: 23 September 2013 Accepted article published: 3 December 2013 Published online in Wiley Online Library: (wileyonlinelibrary.com) DOI 10.1002/jsfa.6510 Essential oil composition of Aegle marmelos (L.) Correa: chemotypic and seasonal variations Ram S Verma, * Rajendra C Padalia and Amit Chauhan Abstract 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)-β -ocimene (0.7–7.9%), α-pinene (<0.05–7.5%), (E)-caryophyllene (0.5–5.3%), β -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)-β -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. c  2013 Society of Chemical Industry Keywords: Aegle marmelos; Rutaceae; essential oil; chemotypes; seasonal variation INTRODUCTION Aegle marmelos (L.) Correa (Rutaceae), commonly known as ‘Bael’, is indigenous to India and found wild all over the sub-Himalayan forests, in Central and South India as well as in Sri Lanka, Pakistan, Bangladesh, Burma, Thailand and most of the Southeast Asian countries. 1 It thrives under arid, semiarid and sub-humid conditions. 2 It is cultivated throughout India, mainly in the temple gardens, because of its status as a sacred tree. The plant is valued for its strong and durable timber, edible fruits and many medicinal properties. 3 Leaves, fruits, stem and roots of A. marmelos have been used in ethno-medicine as astringent, antidiarrheal, antidysenteric, demulcent, antipyretic, antiscourbutic, haemostatic, aphrodisiac and as an antidote to snake venom. 4,5 It is a rich source of coumarins, vitamin C and riboflavin. The bark as well as fruits are reputed to be a valuable Ayurvedic medicine for dysentery and various intestinal complaints. 6,7 In addition to the numerous traditional uses, A. marmelos also shows antimicrofilarial, 8 radioprotective, 9 analgesic, 10 anti- hyperglycaemic, antidyslipidemic, 11 anticancer, 12 antidiabetic, 13 insecticidal, 14 antigenotoxic 15 and antioxidant 16 activities in mod- ern research. The leaf essential oil of A. marmelos is known to exhibit antifungal properties. 17 Bioassay screening of the essential oil indicates marginal toxicity against MCF-7 human breast ade- nocarcinoma cells, good larvicidal activity against Culex pipiens, nematicidal activity against Caenorhabditis elegans, and insectici- dal activity against termites, fruit flies and fire ants. 18 The volatile oil composition of A. marmelos has been investigated previously in India 19 – 23 and other countries. 18,24 – 26 These studies clearly indicate the occurrence of substantial chemical diversity in the volatile oil composition of A. marmelos. The content of active plant principles is known to depend considerably on extrinsic and intrinsic factors, including soil and climatic conditions, plant ontogenesis, season of harvest and storage conditions. 27 – 29 Therefore, knowledge of chemotypic variations and optimal harvesting time are necessary to assure high content of quality extracts. A literature survey revealed that A. marmelos essential oil has been subjected to several studies in different countries; however, systematic information concerning geographical and seasonal variations of essential oil composition of A. marmelos has not been explored. Therefore, the present study aimed to investigate the diversity of leaf volatile oil composition of A. marmelos populations growing in foothills of north India, and to explore the seasonal changes in the volatile oil composition of locally available A. marmelos chemotype. ∗ Correspondence to: Ram S Verma, CSIR – Central Institute of Medicinal and Aromatic Plants, Research Center – Pantnagar, PO Dairy Farm Nagla, Udham Singh Nagar, Uttarakhand 263149, India. E-mail: rswaroop1979@yahoo.com CSIR – Central Institute of Medicinal and Aromatic Plants, Research Center – Pantnagar, Uttarakhand 263149, India J Sci Food Agric (2014) www.soci.org c  2013 Society of Chemical Industry