Antioxidant and antimicrobial activities of the hot pungent chabbarin are responsible for the medicinal properties of Piper Chaba, hunter

摘要

There is great incentive to discover biologically active natural products from higher plants that are better than synthetic chemicals and are much safer, from a health and environmental point-of-view. Now a day, major research emphasis has been given to discover biologically active natural products from plants due to their potent medicinal effects, lower cost and fewer side-effects. Piper chaba, Hunter (Piperaceae) a less well-known spice, is very much effective against cold and cough. The aim of present study is to isolate and identify the bioactive compound which is responsible for its medicinal properties and also evaluate its antioxidant and antimicrobial activity. Molecular characterization was done by chromatographic and spectral analysis. Free radical scavenging potential was assessed by the DPPH (2,2-diphenyl-l picrylhydrazyl) test and antimicrobial activity by inhibition zone test. A strong bioactive compound with hot pungent in nature have been isolated and purified from the acetone extract of Piper chaba stem (20-22% of the dry weight with 99.9% purity). Chromatographic and spectral analysis revealed the compound to be 5-Benzo (1,3) dioxol-5-yl-l-piperidin-l-yl-penta-2,4-dien-l-one or designated as chabbarin. This fraction showed significant DPPH radical scavenging activity with IC50 values of 3.0 μg mL~(-1). It was highly effective on gram negative bacteria than gram positive. In case of Escherichia coli and Pseudomonas aeruginosa (gram negative), maximum inhibitory activity was noticed at 1500 ppm. The Minimum Inhibitory Concentration (MIC) for Escherichia coli was found at 0.01562 mg mL~(-1) whereas in Pseudomonas aeruginosa, it is at 0.00391 mg mL~(-1). In Staphylococcus aureus and Sarcina lutea (gram positive) MIC was detected at 0.00781 mg mL~(-1). Chabbarin also exhibited a remarkable antifungal activity. Aspergillus tamarii is very much sensitive to chabbarin (MIC at 0.01562 mg mL~(-1)) than Penicillium chrysogenum, Aspergillus niger and Aspergillus fumigatus (MIC at 0.03125 mg mL~(-1) So Chabbarin is responsible for the medicinal properties of the plant.