Phytochemicals from the stem bark of Calophyllum ferrugineum Ridl. and Calophyllum andersonii P. F. Stevens and their bioassays / Izzah Afifah Noh

Plant from the genus Calophyllum were known for its medicinal properties and used to treat swollen gums, arthritis, diarrhoea, chronic abscess, skin infections and lesion. The species, Calophyllum ferrugineum and Calophyllum andersonii from Sarawak has least studied about their phytochemical constituents and biological activities. The aims of this study are to isolate and identify the phytochemical constituents from both species and to determine the antibacterial and antioxidant activity. The plant stem barks were collected from Semenggoh Nature Reserve in Sarawak and underwent maceration process to extract the samples. The extracts were subjected to chromatographic methods for the isolation and purification processes. Structural elucidation was achieved by using IR, MS, 1D and 2D NMR. The further isolation process from both species by using column and centrifugal chromatography has afforded different classes of compounds such as triterpene, xanthone, coumarin and fatty acid. Calophyllum ferrugineum afforded four compounds from n-hexane, chloroform and methanol extracts namely friedelin (5), lupeol (100), 1-hydroxy-7- methoxyxanthone (77), isocalanone (11). Meanwhile, Calophyllum andersonii afforded seven compounds namely linoleic acid (91), oleic acid (90), thwaitesixanthone (84), euxanthone (64), pyranojacareubin (54) and mammea A/BB cyclo F (101) from n-hexane, chloroform and methanol extracts. There were 10 compounds in total from both species. Friedelin (5) was recorded presence in both species. Isocalanone and methanol extract of C. ferrugineum showed appreciable antioxidant activity with the IC50 values of 27 ± 5.23, 38 ± 7.04 and 34 ± 3.70 μg/mL compared to the positive control; quercetin (15.5 ± 1.38 μg/mL) and ascorbic acid (14.2 ± 1.21 μg/mL), respectively. The chloroform and methanol extracts from both species showed significant inhibitions against S. aureus, B. subtilis, P. aeruginosa and E. coli with MIC and MBC values ranging from 225 and 112.5 μg/mL compared to the positive control. The results obtained from this study highlighted the potential of both species as antibacterial and antioxidant agent.