e., 1, 3, 5–7, 10–16, 21, 31, 33, 37, 39–46; in total 30 known compounds from literature. The hemiterpene, 2-methyl butanoic is derived from 3, 3-dimethylallyl pyrophosphate and isopentenyl pyrophosphate, and has the highest odor impact among the non-sulfurous odorants. 11 The co-occurrence of β-caryophyllene and caryophyllene oxide, suggests oxidation of β-caryophyllene into the latter. The constituent α-ylangene, a tricyclic sesquiterpene is responsible for the ‘pepper’ aroma of the heartwood derivatives. 2-octen-1-al is derived from autoxidation of unsaturated fatty acids. 12 The aldehyde, 5-methyl-2-furfural

is a sugar degradation product, along with CAL-101 cell line benzaldehyde possibly, contribute to the powerful sweet and spicy odor of sandalwood oil. Furthermore, the saturated and unsaturated volatile C6 and C9 compounds are mainly responsible for the “fresh green” odor of the leaves.

Cis-3-hexenyl acetate is derived via lipoxygenase cleavage of fatty acids within seconds of injury 13 are one of the “green-leaf volatiles” with a grassy odor that are typically found in the case of damaged leaves. The carotenoid derivatives β-ionone and dihydroactinidiolide 14 display antibacterial and antifungal activities. Benzoic acids are derived from l-phenylalanine metabolism via benzaldehyde 15 and occur naturally free or esterified as methyl or ethyl esters. Naphthalene derivatives and Selleckchem SB203580 azulenes act both as protection against insects and as markers for attraction by virtue

of their UV absorption. 16 Hexadecanoic and octadecanoic acid commonly occur in medicinal plants. Amongst, the 6.7% unidentified constituents, the most were santalol and santalene-derivatives, as evident from their mass spectrum, but results were inconclusive due to ambiguities of identification between closely matching chemical structures, improper separation and co-elution. The most of the volatiles belonged to sesquiterpene hydrocarbons (12), n-alkanes (8), oxygenated terpenoids (6) and non-terpenoids Rutecarpine showing much quantitative variations. Moreover, the oxygenated sesquiterpene content (33.16%) was highest, followed by sesquiterpene hydrocarbons (26.88%), n-alkanes (10.15%) and fatty acids (3.58%). Among the oxygenated sesquiterpenoids, Z-α-santalol (28.75%) and epi-β-santalol (9.42%) were the major constituents whereas among the sesquiterpene hydrocarbons, the major constituents were, α-santalene (6.92%) and β-santalene (6.38%). Essential oil analysis is amenable to analysis by gas chromatography–mass selective detector (GC–MSD), as they have mixtures of terpenes and phenyl propane derivatives in which, the chemical and structural differences between the compounds are minimal with resulting mass spectra being very similar and peak identification being difficult.10 Furthermore, the complexity of natural essential oils necessitates their analyses of temperature-programmed conditions instead of isothermal conditions.