Cashew (Anarcadium occidentale L.) nut shell liquid : fractionation, anarcadic acid derivatization and evaluation of antimicrobial activity

Date

4-2007

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Hidelisa P. Hernandez

Co-adviser

Ernesto J. Del Rosario

Committee Member

Josefina E. Solivas

Abstract

Natural CNSL seas mechanically expelled from the cashew nut shells using Carver press. Using this method of extraction. 10.4% natural CNSL was recovered. Anacardic acid was isolated from natural CNSL by first precipitating it as a calcium salt. followed by acidification then extraction. The percent recovery of anacardic acid was 54.7%. Technical CNSL was prepared by heating natural CNSI. with calcium oxide in water (calcium hydroxide) at 140-150. C. Cardanol was isolated from the technical CNSL mixed with 25% ammonium hydroxide solution. The percent recovery of cardanol was 81.6 %. The Components of the natural and technical CNSL as well as the purity of isolated anacardic acid and cardanol were monitored by TLC. The ether derivative of anacardic acid (2-ethoxy-6-pentadecylbenzoic acid) was synthesized using the principle of wiIlinntsom ether synthesis. The synthesis had a yield of 70.9%. The formation of the derivative was monitored by TLC. The anacardic acid and ether derivative were analyzed by UV, NMR, and 10 spectroscopy and the results confirmed the formation of the derivative and side products. The antimicrobial assay was done using the two-fold microdilution method. The minimum inhibitory concentration (MIC) was measured after the 12-hour incubation period. Representatives of three typical microorganisms frells BIOTECH were used. These include S'iaphylococcus carrells B-1823 :Ind Bacillus subtills 8-1514 for Gram-positive bacteria. Escherichio cull 13-1025 and Pseudonionas aerz,inoso 8-1824 for Gram-negative bacteria. and Condida albicons 3-2219 and Sacch,tromyces cereiseae B-2006 for yeasts. The crude natural CNSI.. and anacardic acid were the most active against Gram-positive bacteria with MIC of 3.9 ppm for both Soureus and B. subtilis. Technical CNSL is inactive with MIC of 500 ppm for S. aureus and 1000 ppm for B. suhtilis. The weakcnint, of the activity is due to the decarboxylation and conversion of the most active anacardic ao.id to the least active cardanol. The MIC of cardanol was found to be 250 ppm for S oureus and 1000 ppm for 13. subtilis. The effect of the functional groups of CNSL commie'nts to the antimicrobial property was studied by measuring the antimicrobial activity or the compounds treated with bases. The activity of the alucardic acid was weakened upon treatment with saturated NaHCO:soltition. On the other hand. addition of 5% Na01•1 to cardanol did not show a remarkable effect on the MIC. This showed that the carboxyl group is more important than the phenolic hydroxyl group in the antibacterial activity. To determine the importance of the phenolic and carboxylic groups in the antibacterial activity of anacardic, three derivatives were prepared and their activities were measured. The derivatives tested were anacardic acid ethyl ether derivative, methyl ester derivative, and ethylene glycol ester derivative. All the derivatives were active against Gram-positive bacteria with the ether derivative being the most active. Esterification led to greater reduction in activity compared to etheri The activity of the test compounds were compared with that of ampicillin, which was used as positive control. In the evaluation of activity against S, ou•eus. natural CNSL and anacardic acid were more active than ampicillin. In the case of B. suhtills. the activity of natural CNSL and anacardic acid is comparable to that of ampicillin. All the derivatives of anacardic acid were less active than ampicillin against both 5 anren, and /3 .Ntibtili.s. Therefore. anacardic acid and its derivatives are potential antibacterial agents against the Grain-positive bacteria.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2007 C4 L65

Document Type

Thesis

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