Essential Oil From Psidium guajava Leaves: An Excellent Source of β-Caryophyllene

The purpose of this study was to investigate the chemical composition of the essential oil extracted from Psidium guajava leaves and to explore the medicinal value of β-caryophyllene in pharmaceutical science. The essential oils of P. guajava leaves were extracted by the hydrodistillation method, using a Clevenger-type apparatus and the chemical composition of essential oils was investigated by gas chromatography–mass spectrometry. The yield of extracted essential oils was 0.6% (w/w) dry weight. The main compounds found in the leaves were β-caryophyllene (20.34%), globulol (8.20%), trans-nerolidol (7.72%), aromadendrene (4.34%), cis-α-bisabolene (3.82%), tetracosane (3.68%), octadecane (3.66%), Z, Z, Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (3.44%), β-bisabolene (3.41%), limonene (3.09%), octacosane (2.88%), δ-cadinene (2.52%), and 1,4-cadadiene (2.04%). The main chemical class of the essential oil was terpenoids, which represent 71.65%, followed by hydrocarbons (26.31%). A total of 50 components were identified, among these β-caryophyllene was found to be dominant, which has great medicinal value, and some other compounds were also identified for the first time in the essential oil of P. guajava leaves.