Ultrasonic Assisted Extraction and Gas Chromatography-Tandem Mass Spectroscopy (GC-MS/MS) Analysis of Extracts from Four Cassia Species

Abstract

Ultrasonic assisted extraction (UAE) process increases the rate of extraction, the yield of extracted components and reduces extraction time. The high sensitivity of GC-MS/MS provides reliable identification of phytoconstituents present in a plant extract. This research is to develop an easy and effective method for the extraction and analysis of phytochemicals in C. singueana, C. sieberiana, C. tora and C. occidentalis using UAE and GC-MS/MS techniques. The crude extracts obtained from the four Cassia species under UAE conditions of 50 mins extraction time, 50 oC extraction temperature and 20 mL/g solvent to sample ratio were analyzed using GC-MS/MS. Thirty-four compounds were identified by comparison of their mass spectra with those in the National Institute of Standards and Technology library, requiring at least 80% similarity. These compounds comprise fatty acids, fatty alcohol, carboxylic acid, long-chain alkanes, diterpenes, triterpenes, sterols and anthraquinones. n-Hexadecanoic acid and phytol were identified in all the Cassia species while anthraquinone was detected only from the methanol extracts of C. tora and C. occidentalis. The bioactivities reported in the literature for these compounds corroborate with the phytoconstituents identified in these plants and support the ethnomedicinal uses of these Cassia species.