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 Melia azedarach extracts, is an interesting approach to overcome these hazards. Unfortunately, the
limonoids found in M. azedarach 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 M. azedarach, 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
m/z 557 and [M + Na]+ (adducts ions m/z 681 and m/z 667), MALDI-MS can be used for detection of meliatoxins A1/B1 or A2/B2 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 M. azedarach samples.
Key words
Melia azedarach
- Meliaceae - MALDI-MS - Meliatoxin - limonoids - chinaberry
