ISOLATION, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF AN AROMATIC ESTER FROM IPOMOEA CARNEA STEM BARK

Abstract

Medicinally important plant species Ipomoea has been reported in Indian system of medicine since ancient times. Ipomoea
carnea is one of those reported as used in folk medicine. Ipomoea carnea belongs to the family convolvulaceae and fistulosa
sub-family. It is a wild herb, largely available in all states of India and a native of South America. Many Ipomoea species
having antimicrobial activities were reported in literature. Taking this into consideration, steam distillation of fresh stem
bark of Ipomoea carnea was carried out to isolate potentially bioactive compound. Antibacterial activity of steam volatile
mixture was performed and it showed significant activity against Klebseilla pneumonia (ATCC33495), Proteus mirabilis
(ATCC12453) and Pseudomonas aeruginosa (ATCC10662). Therefore, bioguided separation and isolation of compound A
was performed. Compound A, a bioactive secondary metabolite; (Z)-4- hydroxyphenyl-4', 5'-dimethylcyclooct- 4'-enecarboxylate was isolated for the first time from stem bark of this plant source. The structure of the isolated compound
was elucidated by IR, MS, ¹H-NMR, 13CNMR, DEPT, etc. Isolated compound; A exhibited promising activity against
above mentioned bacteria. 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.