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.