Suregada multiflora Root Fluro-PolyPhosphate-Glycoside (NU2) inhibits MDR Bacteria and Unicellular Parasites Targeting DNA Topoisomerase I

BackgroundCommon antibiotics were useless now as mdr genes were gradually accumulating in all environmental bacterial plasmids. Thus, development of alternate to synthetic antibiotics is great. ObjectivesPlants secrete ex-metabolites to prevent soil bacteria and thus a good source for new antibiotics. Our objective is to discover an abundant active phyto-chemical against MDR pathogens from household plants of West Bengal. MethodsSuregada multiflora plant was grown in clay pot. Root ethanol extract was made for overnight at RT and concentrated. Preparative TLC was performed to isolate major active component by UV-shadow method and was further purified by HPLC. NU2 Inhibitory assays on MDR Escherichia coli KT-1, Leishmania donovani promastigotes, Plasmodium falciparum in human RBC culture were performed as described previously. Biochemical assays, elementary and spectral analyses (MASS, FTIR, NMR) were performed to validate chemical nature of NU2. DNA Topoisomerase I, RNA polymerase and DNA polymerase assays were performed to find modes of action. The structures of NU2 were drawn using Stacher and NU2 binding to DNA topoisomerase I was performed using SwissDock server [Bugnon et al. 2024]. ResultsWell cultivated S. multiflora root extract was 18fold active than bark extract and further enhanced 2.8fold in MS media root culture. The four times TLC purified active principle (NU2) was eluted at 10.2min in HPLC C18 column. NU2 inhibits MDR bacteria as well as unicellular parasites Plasmodium falciparum, Leishmania donovani and Trypanosoma brucei. Spectral analyses suggested NU2 was a glycoside-polyphosphate with molecular mass 454mu and molecular formula C4H7P4O16F. FT-IR gave broad band at 3000-3600cm-1 for -OH including at 1559cm-1 for -OH bending. The distinct phosphate -PO4-3 group absorption was confirmed at 1021.4cm-1 including 928.7cm-1 for C-O-P and skeleton minor phosphate group vibration at 525cm-1. Proton-NMR demonstrated huge absorption at {delta}=2.16ppm for C-O-H, at {delta}=1.52ppm for -POH while Carbon-NMR at 30.1ppm for C-H and at 207.01ppm for -HC=O. NU2 actively inhibited the DNA topoisomerase I but DNA polymerase and RNA polymerase of Escherichia coli were not inhibited. The AI-guided computer simulation suggested that NU2.1, NU2.2 and NU2.3 were better inhibitors for topoIII than topoI of E. coli, M. tuberculosis and L. donovani. We postulate that NU2 prevent the DNA nicking, strand passing and ligase activities after specific binding to the domain-2 active sites. ConclusionThus, NU2 cyclic glycoside-fluoropolyphosphate may be a versatile type-I DNA topoisomerase inhibitor and could be studied further for drug design against bacterial and parasite drug-resistant pathogenesis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/619771v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1017feaorg.highwire.dtl.DTLVardef@174eea1org.highwire.dtl.DTLVardef@1de8ed3org.highwire.dtl.DTLVardef@72df67_HPS_FORMAT_FIGEXP M_FIG C_FIG