Antibacterial activity of Dibutyl Phthalate : A secondary metabolite isolated from Ipomoea carnea stem.

Medicinal plants have been used for centuries as remedies for human disease as they contain components of therapeutic value. Ipomoea carnea is one of those reported as used in folk medicine. Ipomoea carnea belongs to convolvulaceae family and fistulosa sub-family. It is a wild herb, largely available in all states of India and a native of South America. It is a green manure crop and also used as a folk medicine. Many Ipomoea species having antimicrobial activities were reported in literature. Taking this into consideration, chromatographic separation of the components from ethyl acetate extract of the stem of I. carnea was carried out. A bioactive secondary metabolite – dibutyl phthalate was isolated for the first time from this plant source. The structure of the isolated compound was elucidated by IR, MS, 1 H-NMR, 13 C- NMR, DEPT, etc. The antibacterial activity of the isolated compound was assayed in vitro by Agar disc diffusion method against gram negative bacteria Klebseilla pneumonia (ATCC33495), Proteus mirabilis (ATCC12453) and Pseudomonas aeruginosa (ATCC10662) in concentration 40 µL/m .The compound showed significant activity against the tested strains. MIC study of the isolated compound was also carried out. Pseudomonas aeruginosa was found most susceptible as the compound showed the highest activity against this strain. The antibacterial activity was determined by using disc diffusion method. Streptomycin was used as a standard.