Coupling the high-resolution LC–MS characterisation of the phenolic compounds with the antimicrobial and antibiofilm properties of helencha (Enydra fluctuans Lour.)


This study reports the polyphenol profile of helencha (Enydra fluctuans Lour.), an underutilised, aquatic leafy vegetable, based on high resolution accurate mass analysis. The methanolic extract of helencha leaves was screened by ultra-high performance liquid chromatography with quadrupole time of flight mass spectrometry (LC-QToF-MS). An in-house developed database of phytochemical metabolites was referred for compound identifications. Based on the detection of the pseudomolecular ion and at least one molecule-specific fragment ion (each with < 5 ppm of mass error), 25 potentially-bioactive phenolic compounds were putatively identified. These included 6 flavonols, 4 phenolic acids, 3 lignans, 3 flavones and 1 each of flavanol, flavanone, dihydroflavonol, tetramethoxyflavone, isoflavonoid and methylated flavonol. In addition, 3 unclassified compounds are also reported. The helencha extract showed antibiofilm properties with a potent bacteriostatic activity against the clinical isolates of Pseudomonas aeruginosa, a human pathogenic bacteria. The complementary molecular docking studies indicated strong binding interactions of the identified compounds with the active site of LasR protein of P. aeruginosa. The in vitro and in silico study results would be useful to develop novel neutraceutical products based on helencha-extract and design new lead compounds to control the biofilm producing pathogenic microorganisms.

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Data availability

All data are presented in the manuscript in Figures and Tables. The background data, if required, will be made available on request.



Liquid chromatography mass spectrometry


High performance liquid chromatography


liquid chromatography- quadrupole time of flight mass spectrometry


Optical density


American type culture collection


Protein data bank partial charge (Q) atom type (T)


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We acknowledge the contribution of Suparna Banerjee for her language help and writing assistance. Our heartfelt thanks are due to Kisalay Sarkar for helping us in receiving authentic helencha plant materials from West Bengal.


No external funding was received to conduct this research.

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TKK: Designed the research, performed polyphenol extraction and interpreted the results for characterisation of the plant material. ZK: Performed LC–MS analysis, mass spectra interpretations. DO: LC–MS interpretation, identification of polyphenols, polyphenol profiling. TB: Interpretation of microbiological tests and writing of the concerned results and discussion. AS: Performed the microbiological tests. SGK: Performed the in silico studies and interpreted those results. KB: Designed the research study, developed results and discussion, manuscript writing and overall guidance.

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Correspondence to Kaushik Banerjee.

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Koley, T.K., Khan, Z., Oulkar, D. et al. Coupling the high-resolution LC–MS characterisation of the phenolic compounds with the antimicrobial and antibiofilm properties of helencha (Enydra fluctuans Lour.). J Food Sci Technol (2021).

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  • Helencha (Enydra fluctuans)
  • Phenolic profiling
  • High resolution LC–MS
  • Antibiofilm
  • in silico molecular docking