Ethnobotany of the K'ekchi' Maya of Southern Belize and a Search for Novel Pesticide Models

Abstract

The demand for new, more effective, and environmentally friendly pesticides is greater today than ever before. Many scientists have suggested that the natural world may harbor such compounds. This research employed the techniques of ethnobotany and natural products chemistry to identify potential plant sources for novel pesticide models.

Fieldwork was conducted in the Toledo District, Southern Belize from May until December of 1999. Interviews, surveys, and participant observation were accomplished within multiple K'ekchi' Maya villages including Indian Creek Village. A collection of 95 medicinal plants was made for herbarium submission based on information provided by four "bushdoctors" and a number of guides.

Extraction, isolation, and chromatography methods were used to separate compounds for bioassay examination. Four bioassays against bacteria, fungi, insect, and seed germination were utilized to examine crude extracts of six bulk samples. Three of the specimens, Aristolochia Schippi, Bursera simaruba, and Hippobroma longiflora showed positive activity in at least one of the bioassays described.

The volatile fraction of A. Schippi showed strong seed germination inhibition against lettuce and thyme in Conway dish assays. My informants identified Hippobroma longiflora as a poisonous plant. NMR analysis of this plant showed that the active compounds are variations on the lobeline alkaloid theme found in other members of the Campanulaceae. Three new lobeline analog compounds, 3-dehydro-8,10-Diethyllobelionol, 3-dehydro-Lelobanonoline, and Lobelanidine N-oxides, were discovered. The K'ekchi' Maya and others have used the bark of Bursera simaruba extensively to treat a variety of skin ailments including infection, rashes, and wounds. Pheophytin was found to have properties that address all aspects of the first stages of wound healing including anti-bacterial and anti-inflammation properties.

In addition to the chemical information learned, new data has been gained regarding disease diagnosis and treatment among K'ekchi' bushdoctors in Southern Belize. The value and difficulties of conducting ethnobotanical studies has been discussed. Information acquired from this research has contributed to the search for novel biocides and offers support for the merit of conducting such research.