Comparative Studies of Essential Oil Composition and Biological Activities of Callistemon citrinus from Western Himalaya

This work described a comprehensive study to estimate chemical constituents of essential oils (EOs) extracted from different parts of the Callistemon citrinus viz: fruits, leaves and aerial part. The EOs were characterized using physicochemical parameters, and GC‐FID/MS. It was observed that among different parts, aerial part has the highest oil yield (0.90 %) followed by leaves and fruits. Further, seventeen compounds were characterized, and represented total amount (97.2–99.5 %) with domination of monoterpenes (12.5–34.6 %) and oxygenated monoterpenes hydrocarbon (61.8–86.8 %). α‐pinene (11.8–24.7 %), α‐phellandrene (1.2–3.0 %), p‐cymene (3.3–3.9 %) and 1,8‐cineole (58.3–85.1 %) were found as major compounds in C. citrinus samples. These major compounds are the quality chemical markers of C. citrinus oil. The findings revealed significant quantitative variations in EO composition of samples and were also clearly supported by multivariate statistical analysis. Moreover, EOs were evaluated for glucosidase and colon cancer cell lines inhibitory activities, which were found promising.