Leaf Essential Oil Composition of Six Syzygium Species from the Western Ghats, South India

The Syzygium (Family: Myrtaceae) species are well known for their aromatic nature. Though 45 Syzygium species are reported from the Western Ghats region of India, the volatile oil chemistry of most of these aromatic plants are uninvestigated. The present study reports the chemical constituents of the leaf essential oils of 6 Syzygium species, S. arnottianum Walp., S. caryophyllatum (L.) Alston, S. hemisphericum (Wight) Alston, S. laetum (Buch. Ham.) Gandhi, S. lanceolatum (Lam.) Wight & Arn. and S. zeylanicum (L.) DC. var. zeylanicum, collected from the Western Ghats of Kerala. Sesquiterpenoids were the predominantcompounds in all theSyzygium species studied and -caryophyllene and caryophyllene oxide were present in all the oils except S. laetum. The open chain sesquiterpenoids (Z,E)-α-farnesene and (E)-nerolidol were characteristic of S. laetum while phenyl propanoids were exclusively present in S. lanceolatum