Abstract: 【Aim】 To explore the chemical composition and the antimicrobial activity of petroleum ether extracts from   Coccinella septempunctata. 【Methods】 The petroleum ether extracts from C. septempunctata adults were identified by using gas chromatography-mass spectrometry (GC-MS), the compounds of nbutanol ether extracts were isolated by Sephadex LH-20, ODS-C₁₈ and silica gel column chromatographic methods, the structures of these compounds were identified on the basis of physicochemical and spectroscopic analysis, and the antimicrobial activity of the petroleum ether extracts against Salmonella enterica, Pseudomonas aeruginosa, Exserohilum turcicum and Rhizoctonia solani was measured by a disk agar diffusion method. 【Results】 Fourteen compounds were identified from the petroleum ether extracts by GC-MS. Seven compounds were isolated and identified from n-butanol ether extracts, which were allantoin, thymine, 4-hydroxy-phenylethyl alcohol, anthranilic acid, adenosine, succinic acid and mannitol. The petroleum ether extracts at the concentration of 100 and 50 mg/mL had an inhibitory effect against S. enterica, with the inhibition rates of 52.78% and 27.05%, respectively, but had no obvious activity against other tested microbes. 【Conclusion】 The results of this study prove that the petroleum ether extracts from C. septempunctata adults have inhibitory activities against S. enterica.

Key words: Coccinella septempunctata, chemical composition, antimicrobial activity, bacteria, plant pathogenic fungi, GC-MS