Abstract

Investigation of the volatile constituents of Araucaria cunninghamii Aiton ex D. Don aerial parts was carried out using the headspace/solid-phase microextraction technique using GC/MS and preparation of its methanolic extract to screen the phytochemical constituents of the aerial parts was carried out to standardize their phenolic and flavonoidal content, as well as antimicrobial screening for the extract. Investigation of the volatile constituents of A. cunninghamii identified a total of 31 volatiles as monoterpene and sesquiterpene. Standardization of the plant methanolic extract showed its elevated content of total phenolics and total flavonoids. Evaluation of the extract’s antimicrobial activities against multidrug-resistant pathogens using the agar well diffusion method was determined at extract concentrations of 100 and 200 mg/ml. The results revealed that the extracts inhibit the growth of the tested Gram +ve spp. with a moderate extent followed by the Gram −ve spp. (−)-α-Pinene was the major monoterpenoid hydrocarbon representing a third of the volatile constituents of the sample 32.95% and this is concurrent with the plant being one of the conifers’ standardization of A. cunninghamii which showed a high total polyphenolic content with 252.11 ± 0.28 mg/gallic acid equivalent and exhibited also a high flavonoidal content of 21.65 ± 0.01 mg/µg compared to the standard quercetin.

Key words: A. Cunninghamii, Agar Well Diffusion Technique, Phytochemical Screening, Total Flavonoids, Total Phenolics, (-)-Α-Pinene