A study of the insecticidal property of the barks of caballero tree (Caesalpinia pulcherrima (L.) SW.)

• Main Author: Matienzo, Ermelinda Mendoza
• Format: text
• Language: English
• Published: Animo Repository 1984
• Subjects: Insecticidal plants; Pride-of-Barbados (Plant); Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/1072; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=7910&context=etd_masteral
• Institution: De La Salle University

The insecticidal properties of the crude extracts of the barks of Caesalpinia pulcherrima (L) SW. were tested on cockroaches of almost the same sizes. Successive extractions were done using hexane, acetone, methanol and water as solvents. The hexane crude extract revealed the highest percentage mortality using Abbott's formula (1925). Thin layer chromatographic analysis of the crude extracts was monitored using acetone, methanol, acetone in petroleum ether and methanol in acetone as developing solvents. Pure acetone, pure methanol and combinations of 30 percent acetone in petroleum ether and 20 percent acetone in methanol did not give good results of separation but 2 percent acetone in petroleum ether was efficient in separating the components of the crude extracts. The active components of the hexane extract were separated and isolated by quick column chromatography. The fraction with a single component, as shown by TLC runs using a 2:8 acetone in petroleum ether as developing solvent was further characterized through infrared and nuclear magnetic resonance spectroscopy. The spectra of the crude residue showed that the active component is most probably a long chain hydrocarbon with isolated double bonds.