Emanations Volume 4

The biodiversity of Dominican Republic has not yet sufficiently been explored for its potential as a source of natural products. Approximately 3,000 plant species have been used for medicinal purposes. Spermacoce assurgens (Rubiaceae), Canella winterana (Canellaceae) and Ruellia tuberosa (Acanthaceae) are three plants used in the Dominican ethnomedicine to treat inflammation. The leaves, stems, bark, fruits, flowers, and roots of these species were collected from Punta Cana and Juanillo, in the province of La Altagracia, Dominican Republic. Antibiotic activity of extracts (in 95% ethanol of all specimens) was tested using disk diffusion assays against the gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and three strains of the fungus Candida albicans. An insecticidal assay was conducted with larvae of Aedes aegypti as well. The crude extracts from leaves, flowers, and roots of C. winterana exhibited strong activity against all microbial strains except E. coli. These extracts also exhibited cytotoxicity in the brine shrimp assay. After separation of compounds using thin-layer chromatography, alkaloids, terpenoids, phenols and antioxidants were revealed utilizing Dragendorff, Vanillin and 2,2-diphenyl-1-picrylhydrazyl reagents. Further work on this plant for potential medicinal chemical compounds could yield interesting results.