Bioactive compounds from the fruit extract of Clausena excavata Burm. f. (Rutaceae)

Abstract

• Sixteen compounds were isolated from the EtOAc extract of C. excavata fruits. • Nine compounds ( 1, 3, 5, 6, 8 – 10, 15 , and 16 ) were isolated from C. excavata for the first time. • The absolute configuration of the bioactive limonoids 15 and 16 were confirmed by the X-ray crystallography using Cu Kα radiation. • Compounds 7 (auraptene) and 14 (safrole) showed a moderate glucose uptake with ratios of 1.38-fold and 1.41-fold, respectively. • The cytotoxicity of auraptene 7, 8 , and 10 against lung cancer A549, RAW 264.7 cells, and colorectal cancer SW480 are reported for the first time in this study. Phytochemical investigation of the fruit extract of Clausena excavata Burm. f. resulted in the isolation and identification of 16 compounds, including seven coumarins ( 1 – 7 ), four phenylpropanoids ( 8 – 10 and 14 ), two benzaldehyde derivatives ( 11 and 12 ), one carbazole alkaloid ( 13 ), and two limonoids ( 15 and 16 ). Of these, nine compounds ( 1, 3, 5, 6, 8 – 10, 15 , and 16 ) were isolated from C. excavata for the first time. The absolute configuration of limonoids 15 and 16 was established by X-ray diffraction analysis using Cu Kα radiation. Some isolated compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines, namely lung cancer A549, colorectal cancer SW480, leukemic K562 cells as well as glucose uptake, glucose consumption, and antibacterial activity against Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA). Compounds 7 (auraptene) and 14 (safrole) showed moderate glucose uptake with ratios of 1.38-fold and 1.41-fold compared to the positive control (metformin, 2.25-fold). Compound 7 (auraptene) also exhibited weak cytotoxicity against lung cancer A549, colorectal cancer SW480, and leukemic K562 cells with IC 50 values of 77.2, 157.3, and 105.3 µM, respectively, while compounds 8 (( E )-piperonylprop-2-enal) and 10 (ethyl p -coumarate) exhibited weak cytotoxicity against RAW 264.7 cells and colorectal cancer SW480 cells with IC 50 values of 234.9 and 219.5 μM, respectively. Compounds 1, 3, 7 , and 14 – 16 showed a MIC of >512 µg/mL revealing them to be inactive. :