Melia azedarach L. in vitro plantlets as a new source of antifeeding salannin- and nimbolinin-type limonoids

Medicinal plants are invaluable sources of bioactive natural products. To further access plant’s biosynthetic and biotechnological potential, plant tissue culture has become a standard practice. Plant biotechnology might offer selected cell lines with higher metabolic production and allow a more controlled environment for plant development and optimized metabolic flux for the biosynthesis of specific compounds. In this work, we established the in vitro growth of Melia azedarach through micropropagation and evaluated its biosynthetic potential. LC-MS-based metabolic profiling investigation was applied to generate information on natural products composition. A set of computational tools including spectral library matching and in silico prediction of molecular structures and chemical classes were employed to annotate M. azedarach’s plantlets chemical space. Our findings indicate salannin- and nimbolinin-type limonoid production and a series of glycosylated flavonoids and lignan-related phenylpropanoids. This is the first time nimbolinin-related limonoids have been produced in vitro, opening a venue for biotechnological applications of such compounds.