Chemical investigation of the methanolic extract of pomegranate fruit following antibacterial activity directed isolation led to the isolation of pelargonidin-3-galactose, cyanidin-3-glucose, gallic acid, quercetin, and myricetin. All these compounds exhibited substantial activity against species of corynebacteria, staphylococci, streptococci, Bacillus subtilis, Shigella, Salmonella, Vibrio cholera, and Escherichia coli. However, all these compounds were more active against Gram-positive species. On comparing the activity of all the isolated pure compounds, it was found that gallic acid showed the highest antibacterial activity against all the tested sensitive strains and the activity of the remaining pure compounds was almost same due to the structural similarities of the compounds. The reason for antibacterial activity of all pure compounds was attributed to their phenolic structure.

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The chemical investigation of the ethanolic extract of the root bark of Onosma hispidum following antibacterial activity directed isolation led to the isolation of 4-hydroxy-3-methoxy cinnamic acid (ferulic acid) and 4-hydroxy-3-methoxy benzoic acid (vanillic acid) which have been reported for the first time in this species. In addition to these compounds, the crude ethanolic extract and methanol fraction exhibited substantial bioactivity against species of corynebacteria, enterococci, staphylococci and streptococci. Ferulic acid was found more bioactive (being relatively more hydrophobic) compared to vanillic acid.

Crude methanolic extracts from Grewia asiatica, Eugenia jambolana and Carissa carandas were separated into four major fractions viz. phenolic acids, flavanols, flavonols and anthocyanins which were then analysed for their total phenolic, flavonoid contents, and antimicrobial effects. In addition, anthocyanin fraction was also analysed for total anthocyanins, total colour and polymeric pigments. Total phenolics and flavonoids were highest in the fractions from E. jambolana and lowest in C. carandas, the order being phenolic acid > flavanols > flavonols > anthocyanins in all fruits. All fractions showed significant antibacterial activity except anthocyanin. Being the most active, phenolic acid fractions were also tested for their antifungal activity, the fractions of C. carandas and G. asiatica substantially inhibited all the tested fungal species. These results are being reported for the first time.