Abstract
Essential oils (EOs) were extracted from the leaves of two Psidium guajava (P. guajava) cultivars (white and pink fruit forms) from the local fields of Faisalabad, Punjab Pakistan. Essential oils were analyzed by GC/MS and the antioxidant, antimicrobial and anti-haem biocrystallisation activities were assessed. GC/MS profiles revealed 40 and 57 compounds with total percentage composition 92.55% and 86.89% in P. guajava white and pink cultivars, respectively. The major compounds (>5%) found in EO of P. guajava white were caryophyllene (9.08%), dihydrocarveol acetate (7.04%), nerolidol (6.69%) and caryophyllene oxide (6.18%) whereas α-phellandrene (11.66%), eucalyptol (10.01%), α-terpineol (7.78%) and spathulenol (5.71%) in P. guajava pink. Essential oils showed moderate antioxidant potential. The P. guajava pink cultivar had comparatively high antioxidant potential than P. guajava white while both had comparable antimicrobial potential. Essential oils from both of the cultivars of P. guajava exhibited poor anti-haem biocrystallization activity. Results revealed that the EO of P. guajava pink cultivar has high phenolic content as compared to P. guajava white and thus the greater antioxidant potential. Whereas the antimicrobial potential of both was almost equal. The results also revealed that both EOs have poor antimalarial activity in comparison of standard drug. Both qualitative and quantitative variations were observed in chemical composition of both EOs.