eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2022-12-20 15 4 2217 2227 10.13005/bpj/2559 46445 article Enas Abd al-Raouf Ammar Semysim 1 Department of Biology, University of Kufa, Faculty of Science, Najaf, Iraq. Curcuma longa L. rhizome extracts have polyphenolic secondary metabolites called curcuminoid and various volatile oils. These compounds exhibit wide spectrum of antibacterial activity. Ethanol and petroleum ether C. longa rhizome extracts were studied for their antibacterial action against two bacteria, Escherichia coli and Staphylococcus aureus. This activity had evaluated by employing Agar Well Diffusion method. Curcuminoid was interpreted by pattern of High Performance Liquid Chromatography (HPLC). The ethanol extract exhibited inhibitory effects against E. coli and S. aureus at concentration 150 mg/ml with diameter of inhibition zone (23.000 ± 0.57735 and 27.000 ± 0.57735mm) respectively. On the contrary, petroleum ether extract had inhibitory effects for E. coli and S. aureus at concentration 150 mg/ml in diameter of inhibition zone (39.000 ± 0.57735 and 41.000 ± 0.57735mm) respectively. Quantitative analysis for the curcuminoid compounds from C. longa rhizome extracts revealed highest curcumin, demethoxycurcumin and bisdemethoxycurcumin (9.12, 5.93 and 23.96 µg /ml) respectively in the extract of petroleum ether. We concluded that the C. longa extracts exhibited inhibitory effects against pathological bacterial growth. The essential oils obtained by petroleum ether extract of C. longa rhizome was more influential inhibition than ethanol extract against E. coli and S. aureus. https://biomedpharmajournal.org/vol15no4/evaluation-of-antibacterial-activity-of-extracts-of-curcuma-longa-l-rhizome-and-estimation-of-curcuminoid-by-hplc/ Curcuma  Curcumin Diarylheptanoid Chromatography Escherichia coli Staphylococcus aureus