Identification of Meliatoxins in Melia azedarach Extracts Using Mass Spectrometry for Quality Control

Abstract

Indiscriminate use of synthetic pesticides can be hazardous to both humans and the environment, but the use of natural products as a source of bio-based products, such as extracts, is an interesting approach to overcome these hazards. Unfortunately, the limonoids found in with desired insecticidal properties (e.g. azadirachtin) may also be present with limonoids toxic to mammals. The goal of this report was to develop a fast and reliable MS-based experiment to characterize meliatoxins in crude extracts of in order to provide unequivocal assessment of the safety for extracts for application in the field. MS and MS/MS experiments using MALDI ionization were evaluated as tools for the assignment of characteristic ions produced by each meliatoxin in crude extracts.The use of different experiments in combination, such as the analysis of fragment 557 and [M + Na] (adducts ions 681 andz 667), MALDI-MS can be used for detection of meliatoxins A/B or A/B in a crude extract and may be used to discriminate meliatoxins A from B, respectively. Subsequent MS/MS experiments can distinguish between the presence of group 1 and/or 2 in each class of meliatoxins classifying the proposed approach as a quick and efficient quality control method of meliatoxins in real samples.

MS diagnostic model and rapid distinguishing of bioactive limonoids in fruits of Melia toosendan using solid‐phase extraction coupled with LC–MS/MS

“…Studies regarding characteristic tandem mass spectrometry (MS/MS) fragmentations are limited due to the difficulties associated with the complex extracts. Almost all MS/MS fragmentations of limonoids only feature losses of substituents 6–10 . Therefore, it is necessary to establish a method to enrich and distinguish the limonoids from crude plant extracts.…”

Recent applications of high resolution mass spectrometry for the characterization of plant natural products

“…This work demonstrates that MALDI-TOF analysis is a rapid tool to obtain standards and to achieve reproducible protocols for extraction, purification and characterization of natural products. On the other hand, Cornelio et al[70] developed a quick and efficient method based on MALDI-LTQ to confirm the presence of meliatoxins A1/B1 and A2/B2, two toxic limonoids, in the Melia azedarach extract, a promising natural product for sustainable pest management systems. The MS and MS/MS fragmentation patterns serve as fingerprints of meliatoxins and are useful for their identification in other natural products.MALDI-TOF has also been used to establish tissue distribution of metabolites.…”