Phytochemical Constituents and Antimicrobial and Grain Protectant Activities of Clove Basil (Ocimum gratissimum L.) Grown in Nigeria

Abstract

<i>Ocimum gratissimum</i> Linn (Lamiaceae) is an herbaceous plant reputed for many medicinal and agronomic practices amongst Nigerian peasant farmers. <i>O. gratissimum</i> was investigated for antimicrobial activity against ten micro-organisms and for grain protectant activity against <i>Callosobrochus maculatus</i>. The phytocontituents of the aerial part of <i>O. gratissimum</i> were extracted with 95% ethanol using the percolation method. The crude ethanol extracted was further fractionated into hexane, chloroform and methanol fractions. The fractions obtained were screened for phytoconstiteunts, antimicrobial and grain protectant properties. Result showed that hexane fraction exhibited the highest antimicrobial activity against <i>Vibrio cholera</i> and <i>Klebsiella pneumonia</i>. Similarly hexane fraction also showed the highest grain protectant activity. The other extracts of the <i>O. gratissimum</i> did not significantly inhibit both bacterial growth and grain infestation. However, the methanol fraction contains phytocompounds such as phenolic compounds associated with antioxidant properties. The study shows that <i>O. gratissimum</i> extractants are potential sources of antimicrobial and preservative agents.