title: Pheophytin a isolated from the seagrass Syringodium isoetifolium plausibly blocks umuC proteins of select bacterial pathogens, in silico.
abstract: OBJECTIVE
  This investigation is designed to evaluate the antibacterial efficiency of the noodle grass Syringodium isoetifolium, which is commonly found in the Indian coastal waters. Also, this study characterizes the active compound and predicts the mode of action in silico.
  
  
  RESULTS
  Human pathogenic bacteria were treated with crude metabolites of S. isoetifolium. The potent fraction b was analysed by UV/VIS, Spectroscopy RP-HPLC, FT-IR, ESI-Mass and1H and13C NMRs and determined to be a hydrate of pheophytin a (C55H74N4O6). The isolated compound Pheo had MIC values of 6·2 ± 0·7 (Salmonella typhi) and 12·5 ± 0·8 (Escherichia coli and Pseudomonas aeruginosa) μg ml-1. Molecular docking studies of the compound were done to find the binding sites on the pathogens using a Molegro Virtual Docker platform. Pheo targets umuC proteins by binding compactly to five amino acid residues with interaction energy of -3·66 and a Moldock score of -160·175.
  
  
  CONCLUSIONS
  Hence, we conclude that pheophytin a, besides being an accessory photosynthetic pigment, also has proven to be antibacterial against human pathogens. Lesser MIC values with definite binding sites predicted in silico are suggestive of a precise of action for this compound.
  
  
  CONCLUSIONS
  Easy extraction methods of the active compound that has a definite target render this under-explored seagrass a good source of antibacterial compound against human pathogenic bacteria. This learning may favour more researches in this unexplored area to build up Pheo-based natural products as antibiotic therapies.
authors.affiliation: Department of Biotechnology, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: C V
authors.initials: CV
authors.lastname: Sathyanathan
authors.affiliation: Department of Biotechnology, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: B
authors.initials: B
authors.lastname: Jyothirmayi
authors.affiliation: Central Research Facility (CRF), Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: L R
authors.initials: LR
authors.lastname: Sundaram
authors.affiliation: Department of Bioinformatics, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: P A
authors.initials: PA
authors.lastname: Abhinand
authors.affiliation: Department of Biomedical Sciences, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: R
authors.initials: R
authors.lastname: Eswaramoorthy
authors.affiliation: Department of Biotechnology, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
authors.forename: K M E
authors.initials: KM
authors.lastname: Gnanambal
mesh_terms: D035961:Alismatales / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D003198:Computer Simulation; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D029968:Escherichia coli Proteins / Q000737:chemistry; D062105:Molecular Docking Simulation; D010674:Pheophytins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012485:Salmonella typhi / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010674:Pheophytins; C061694:pheophytin a; C078202:UmuC protein, E coli; D004259:DNA-Directed DNA Polymerase
keywords: 
  Syringodium isoetifolium
  ; 
  in silico
  ; antibacterial; pheophytin a; umuC proteins