Antibacterial activity of 14, 15-dihydroajugapitin and 8-o-acetylharpagide isolated from Ajuga bracteosa Wall ex. Benth against human pathogenic bacteria

Ajuga bracteosa Wall ex. Benth. (Lamiaceae) commonly known as Bungle Weed has been in use since ancient times and is mentioned Ayurvedic literature. The upper ground parts of the plant are used for treatment of various diseases. The weed is credited with astringent, febrifugal, stimulant, aperient, tonic, diuretic and depurative properties and is used for the treatment of gout and rheumatism, palsy and amenorrhoea. Two compounds 1) 14, 15-dihydroajugapitin and 2) 8-o-acetylharpagide were isolated from the aerial parts of the plant and tested for antibacterial activity against various pathogenic bacteria by agar well diffusion method. Compound 1 and 2 showed maximum antibacterial activity against Escherichia coli with zone of inhibitions of 25. 0 ± 1.4 mm and 22.6 ± 0.9 mm respectively. The MIC value of compound 1 and 2 ranged between 500 and 1000 μg/ml. It could be concluded that both compounds isolated from the aerial parts of Ajuga bracteosa possess antibacterial activity against pathogens. •Two compounds 1) 14, 15-dihydroajugapitin and 2) 8-o-acetylharpagide were isolated from Ajuga bracteosa.•MIC value of both compounds showed effective activity against some of the routinely isolated clinical isolates.•Significant pathogenic inhibition of compounds provides scientific validation for its traditional use against many bacterial diseases.