Prioritization\nof the Secondary Metabolites for the\nRapid Annotation Based on Liquid Chromatography-High Resolution Mass\nSpectrometry Assessment: Varanasine and Schroffanone from Murraya paniculata and Cytotoxic Evaluation

The liquid chromatography-high resolution\nmass spectrometry (LC-HRMS)\ntechnique enables the detection of phytochemicals present in the extracts.\nLC-HRMS-generated mass list showed abundant compounds of interest,\nartifacts, and primary metabolites. The identification of a secondary\nmetabolite of interest within the extract is very challenging. We\nhypothesized that identifying the “new metabolite” in\nthe whole metabolome is more challenging than identifying it within\nthe class of metabolites. The proposed prioritization strategy focused\non the elimination of unknown and prioritizing the known class of\nsecondary metabolites to identify new metabolites. The prioritization\nstrategy demonstrated on Murraya paniculata for the identification of new metabolites. LC-HRMS-generated information\nis used as a filter to target the secondary metabolite and the new\nmetabolites. This strategy successfully annotated the new coumarin\nand coumarin alkaloids from the mass list of 1448 metabolites. Varanasine\n(<b>3</b>), schroffanone (<b>4</b>), schroffanene (<b>5</b>), and <i>O</i>-methylmurraol (<b>9</b>)\nare new compounds, and coumarin (<b>1</b>, <b>2</b>, and <b>6–8</b>) are known. Varanasine (<b>3</b>) is the\nfirst naturally occurring 7-aminocoumarin with additional <i>N</i>-formyl functionality. The isolates were screened for cytotoxicity\nagainst the panel of cancer cell lines. Varanasine (<b>3</b>) and minumicrollin (<b>6</b>) showed significant cytotoxicity\nand apoptosis-inducing potential. The immunoblot analysis confirmed\ninhibition of apoptotic protein PARP-1 and caspase-3 expression by <b>3</b> and <b>6</b>.