Sucrose esters from coconut fatty acids : synthesis and evaluation of their pesticidal properties

Date

6-2006

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evelyn B. Rodriguez

Co-adviser

Susa May F. Calumpang

Abstract

ABSTRACT

NUALLA, GERARD RODA. University of the Philippines Los Banos June 2006 Sucrose Esters from Coconut Fatty Acids: Synthesis and Evaluation of Their Pesticidal Properties.

Adviser Evelyn B Rodriguez. Ph.D.

Sucrose esters were prepared by the reaction of fatty acid chlorides of lauric acid and coconut oil with sucrose. The esterification reaction employed a 1•2 25 molar ratio of sucrose to fatty acid chlorides. The reaction conditions were designed to maximize the formation of diacyl sucrose esters.

Thin-layer chromatographic analysis of the products showed the presence of mono-, di-, tri-, and tetracyl sucrose esters_ The diacyl sucrose esters were the major product. Qualitative chemical analyses confirmed the presence of a carbohydrate moiety in the molecule and the absence of a free hemiacetal or hemiketal group. Infrared spectroscopy confirmed the presence of the ester group.

The synthesized sucrose esters were tested for their mollusicidal activity against the golden apple snail (Nomacea canaliculata). and insecticidal activity against the common cutworm (Spadoptera litura). Snail contact toxicity assay results showed 100% mortality at 1000 ppm. 500 ppm, and 250 ppm for the sucrose esters of coconut fatty acids. The LC,0 was estimated to be 78.08 ppm using probit analysis For the sucrose esters of lauric acid, LC55 was 35.66 ppm. In comparison, the LC50, of niclosamide, a commercial molluscicide was 40.30 ppm. Cutworm contact toxicity assay results showed 100% mortality at 1000 ppm and 500 ppm for the sucrose esters of coconut fatty acids The LD50 was estimated to be 81.93 ppm. On the other hand, LD50 for the sucrose esters of lauric acid was 62.02 ppm. The LC50/LD50 of the compounds was obtained through probit analysis, to provide a more accurate estimation of the activity

The results show that sucrose esters of coconut fatty acids have molluscicidal and insecticidal activities. Using the mixture of coconut fatty acids as a starting material is cheaper as compared to using the fractionated fatty acids of coconut. Considering the abundance of the starting materials, it would be worthwhile to explore and develop the potential of coconut fatty acid sucrose esters as a pesticide.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2006 C4 N83

Document Type

Thesis

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