Partial Purification and Characterization of Albain 1, a Triterpene with Antimicrobial Activity, from the Wood Extract of Avicennia alba Blume

Secondary metabolites of plants are important resources for development of new drugs. Mangrove plants are very well known sources of wide variety of secondary metabolites. Many of these secondary metabolites from mangroves have been found to possess significant biological activities where human health is concerned. Avicennia albaBlume is one such mangrove plant with reports of having many such secondary metabolites of clinical and commercial interests.Aim:To evaluate antimicrobial activity potential of A. albawood extract and to isolate new bioactive constituent(s) responsible for such biological activity.Methodology: Preliminary screenings of antimicrobial activities in different organic solvent extracts of A. albawood tissue were done by TLC-bioautography method and phytochemical nature of the antimicrobial constituent(s) in the extracts have been studied. One compound exhibiting significant antimicrobial activity, named as Albain 1, has been isolated. MIC value has been determined for Albain 1. The purity and structure of Albain 1 have been determined by HPLC, 1HNMR, FTIR and HRMS etc. analysis.Results: 1HNMR, FTIR and HRMS analysis have found out that the isolated compound Albain1 is a triterpene and the molecular formula is C30H48O4.It has exhibited remarkable antimicrobial activity against Bacillus cereus, Bacillus polymyxa, Bacillus pumilas (MIC 125μg / ml).Conclusion:The observed antimicrobial activity of the isolated fraction of A. albaoffer great potentials in pharmaceutical industries.

An investigation on in vitro and in vivo antimicrobial properties of the antidepressant: amitriptyline hydrochloride

The antidepressant drug amitriptyline hydrochloride was obtained in a dry powder form and was screened against 253 strains of bacteria which included 72 Gram positive and 181 Gram negative bacteria and against 5 fungal strains. The minimum inhibitory concentration (MIC) was determined by inoculating a loopful of an overnight peptone water culture of the organism on nutrient agar plates containing increasing concentrations of amitriptyline hydrochloride (0, 10 µg/mL, 25 µg/mL, 50 µg/mL, 100 µg/mL, 200 µg/mL). Amitriptyline hydrochloride exhibited significant action against both Gram positive and Gram negative bacteria at 25-200 µg/mL. In the in vivo studies it was seen that amitriptyline hydrochloride at a concentration of 25 µg/g and 30 µg/g body weight of mouse offered significant protection to Swiss strain of white mice when challenged with 50 median lethal dose (MLD) of a virulent strain of Salmonella typhimurium NCTC 74. The in vivo data were highly significant (p<0.001) according to the chi-square test.