Integrating UPLC-MS/MS-based molecular networking and NMR structural determination for the untargeted phytochemical characterization of the fruit of Crescentia cujete (Bignoniaceae)

Crescentia cujete (Bignoniaceae), commonly known as calabash tree, is distributed and cultivated throughout most of Tropical America. The fruit pulp is used in folk medicine for the treatment of respiratory diseases such as colds, bronchitis and asthma, and also for gastrointestinal illness [1], [2]. Even though food supplement-derived products from the fruit are commercially available as oral syrup preparations, a comprehensive description of the phytochemical composition of Crescentia cujete and appropriate quality control are still lacking.

In this work, we aimed to characterize the chemical profile of the fruit of Crescentia cujete using an untargeted metabolomics approach including UPLC-MS/MS-based molecular networking, generated at the Global Natural Products (GNPS) Molecular Networking website [3], and conventional isolation and NMR methods as identification strategy.

The untargeted phytochemical characterization allowed for the identification of 65 metabolites, including 8 n-alkyl glycosides, 23 phenolic acid derivatives (such as cinnamoyl and benzoyl derivatives), 15 flavonoids (flavones, and flavanones), 4 phenylethanoid derivatives and 15 iridoid glycosides. Among these, four phenylpropanoid derivatives were described for the first time within this species. In addition, 8-epi-eranthemoside, crescentiol A and crescentiol B are reported as three new iridoid glucosides.

The use of molecular networking as a tool for phytochemical characterization of the fruit of Crescentia cujete provides a detailed phytochemical overview of this plant. The reported results provide a useful guide for the development of analytical methods for the quality control of commercial products containing this plant species and further interpretation of their related pharmacological effects.

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• References

• 1 Das N. et al. Antioxidant activities of ethanol extracts and fractions of Crescentia cujete leaves and stem bark and the involvement of phenolic compounds. BMC Complement Altern Med 2014; 14: 45 .
• 2 Parvin. et al. Evaluation of in vitro anti-inflammatory and antibacterial potential of Crescentia cujete leaves and stem bark. BMC Res Notes 2015; 8: 412.
• 3 Wang M. , et al. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. Nat Biotechnol 2016; 34: 828-837.