Abstract
Moringa oleifera (MO) is a highly nutritious plant, whose leaves and seed pods are consumed in Africa, Asia, sub-Himalayan regions and South America. A novel ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the standardization of the bioactive thiocarbamate compound from MO, niazimicin (NZ) in seeds and leaves, is developed, optimized and validated according to the International Conference on Harmonization (ICH) guidelines, using desipramine as the internal standard. Multiple reaction monitoring detection of transitions 358.05>106.86 and 266.38 > 193.04 with collision energy of 25V and 40V, respectively were used. A gradient was optimized at 35-55%B in 7 min, where mobile phase A is aqueous 0.1% formic acid and B is 0.1% formic acid in acetonitrile. The method proved to be linear in the range of 0.05-100 μg/mL, precise, robust and accurate, with LOD and LOQ of 0.02 and 0.05 μg/mL, respectively. MO seeds were found to contain double NZ content (620 mg% ±3.2%) compared to leaves, and the methylene chloride fraction of seeds comprised triple the amount in ethyl acetate fraction (450 mg% ± 2.4%). Results emphasize that seeds of MO are a much richer source for NZ than the most commonly edible and marketed leaves extracts. The reported method can be used for standardization and quality control of the seeds and leaves NZ content.