Chemical constituents and biological activities of Artocarpus communis and artocarpus odoratissimus leaves extracts / Clifford Junaidi Kutoi

Previous studies revealed that Artocarpus species contained several bioactive compounds with potential to provide relief in treatment of diarrhea, wound healing and liver cirrhosis but never been tested for its cytotoxicity properties against liver cell lines to confirm this traditionally medical uses with modern scientific test. Therefore it would be interesting to study the cytotoxicity properties of isolated pure compounds against liver cell line such as Hep-G2 together with other bioassays such as antioxidant and antimicrobial. The dried leaves of A. communis and A. odoratissimus were extracted using cold extraction in methanol. Various chromatographic methods such as vacuum liquid chromatography, thin layer chromatography and radial chromatography were used to isolate and purify compounds from the methanolic extracts of both plants. Structural elucidation was accomplished using spectroscopic methods such as ultraviolet, infrared, mass spectroscopy, ID and 2D nuclear magnetic resonance. This study resulted in identifying three flavonoids and three triterpenoids namely squalene (130), l-(2,4- dihydroxyphenyl)-3-[8-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-l-benzopyran5-yl]-l-propanone (9), 8-(3,6-dimethyl-2-heptenyl)-4',5,7-trihydroxyflavanone (28), 2-geranyl-2',3,4,4'-tetrahydroxydihydrochalcone (11), stigmasterol (132) and ^-sitosterol (131). The methanolic leaves extracts for both A. communis and A. odoratissimus and some of the isolated pure compounds were tested for its antioxidant and antimicrobial activities. Some of these samples demonstarted interesting results in free radical scavenging activity assay; 2-geranyl-2',3,4,4'- tetrahydroxydihydrochalcone showed the most interesting free radical scavenging activity with IC50 value of 5.84 ug/mL as compared to positive control, ascorbic acid with IC50 value of 10.24 ug/mL while, 8-geranyl-4',5,7-trihydroxyflavanone is comparable with control as IC50 recorded at 12.93 ug/mL. Antimicrobial activities based on MIC and MBC revealed some of the tested compounds exhibited strong inhibition activity against Gram-positive bacteria, Staphylococcus aureus, Streptococcus pyogenes and Gram-negative bacteria, Pseudomonas aeruginosa and Escherichia coli with MIC value between 7.03 to 56.25 ug/mL. Pure compound 2- geranyl-2',3,4,4'-tetrahydroxydihydrochalcone demonstrated the most promising inhibition activity against both Gram-positive with MIC value of 7.03 ug/mL