Extraction and chemical characterization of neem seed oil (Azadirachta indica)

Abstract

The neem tree (Azadirachta indica A. Juss) is known for its therapeutic, pesticide, fertilizer and pharmacological properties. Due to these attributes, this tree has economic potential and continues to be used worldwide. For oil extraction, the Sohxlet system was used, for the extraction and characterization of volatiles, the HS-SPME/GC-MS method was used, and the fatty acid profile was characterized by GC-FID. The average yield obtained from the oil was 23%. A total of 34 volatile compounds were detected, of which 9 were identified by Kovat's index: 2-methyldecane, 3-methyldecane, 4-methyldecane, 2-methylundecane, 3-methylundecane, 3,4-dimethylthiophene, 2,5-diol- 3-hexane, 1,2,3-trimethylbenzene and buticyclohexane. In addition to the volatiles in the oil, 7 fatty acids were found; oleic acid, linoleic acid, palmitic acid and stearic acid, with the oil extracted from the seeds having the highest concentration of oleic acid and linoleic acid in commercial neem oil. Given the presence of these chemical compounds in neem oil, it is suggested, for subsequent investigations, the isolation and application of organosulfur compounds as insecticides. The extraction of oil from flowers and neem seeds with solvents that are less harmful to the environment, together with its application, makes it possible to evaluate its pesticide potential. In addition, it is essential to evaluate the influence of neem on the bee population, analyzing cases of mortality and seeking solutions to avoid environmental damage. Additionally, the viability of neem oil as an industrial and hospital cleaning product is highlighted, exploring antimicrobial, antibacterial and biodegradable properties.