Extraction, Profiling, and Characterization of Phytosterols and Triterpenoids from Pili (Canarium ovatum Engl.) Pulp Oil Exhibiting Antioxidant and Antibacterial Properties

Abstract

Pili (Canarium ovatum Engl.), an indigenous tree found in the Philippines, is highly regarded for its fruit due to its high economic value. During processing, the pulp is often discarded as waste but contains considerable amounts of oil and bioactive minor lipid components. The present study explored the antioxidant and antibacterial properties of saponified diethyl ether extract of pili pulp oil and related this activity to the nature of compounds present in the extract through GCMS. The extract indicated the elution of 18 major compounds which are mostly cyclic triterpenic (α-and β-amyrin, lupenone, and β-amyrone) and phytosterol (β-sitosterol, brassicasterol, and stigmasterol) class of compounds. Characterization of the bioactivity of the extract showed high antioxidant activities measured by DPPH radical scavenging (EC50: 74.45 ± 1.29 μg/mL) and lipid peroxidation inhibition (EC50: 3.02 ± 0.06 μg/mL) activities that were comparable with that of α-tocopherol. Moreover, an observed bactericidal activity was demonstrated by the extract against E. coli and S. typhi with MIC values of 40 and 35 μg/mL, respectively. The observed bioactivity of the pili pulp oil extract can be attributed to these compounds which may provide desirable health benefits.