title: Synthesis of novel bisindolylmethanes: New carbonic anhydrase II inhibitors, docking, and 3D pharmacophore studies.
abstract: In this study, 45 bisindolylmethanes having sulfonamide moiety had been synthesized through 3 steps. In vitro assay for inhibition of carbonic anhydrase showed that some of the compounds having sulfonamide moiety are capable of inhibiting carbonic anhydrase II. Bisindoles having halogens at fifth position showed better inhibitory activity as compared to unsubstituted bisindoles. The results obtained from in vitro inhibitory activity were subjected through 3D QSAR and docking studies to identify important features contributing to the activity and further improve the structure. Pharmacophore studies suggest that bisindolylmethane moiety is contributing significantly towards the inhibition activity. Docking studies showed that compounds having nitro substituent (5g and 5i) were found to be able interact with Zn(2+) ion, Thr199, His94, His96, and His119, which interferes with the ZnOHThr199Glu106 hydrogen bond network. Bulky nitro substituent at ortho position for compound 5g prevents the compound from interacting with other residues like Thr199 and Thr200. Methyl substituent at ortho position for Compound 5i induces less steric hindrance effect, thus allowing second oxygen atom of sulfonamide to interact with Thr199 (2.51Å). Hydrogen bonding between NH on indole ring with Glu69 might have increased stability of ligand-receptor complex.
authors.affiliation: Atta-ur-Rahman Institute for Natural Product Discovery, Universiti Teknologi MARA (UiTM), Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Faculty of Applied Science UiTM, 40450 Shah Alam, Selangor, Malaysia.
authors.forename: Syahrul
authors.initials: S
authors.lastname: Imran
authors.affiliation: Atta-ur-Rahman Institute for Natural Product Discovery, Universiti Teknologi MARA (UiTM), Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Faculty of Applied Science UiTM, 40450 Shah Alam, Selangor, Malaysia. Electronic address: taha_hej@yahoo.com.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Taha
authors.affiliation: Atta-ur-Rahman Institute for Natural Product Discovery, Universiti Teknologi MARA (UiTM), Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Faculty of Applied Science UiTM, 40450 Shah Alam, Selangor, Malaysia. Electronic address: norhadiani@salam.uitm.edu.my.
authors.forename: Nor Hadiani
authors.initials: NH
authors.lastname: Ismail
authors.affiliation: Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Sharmeen
authors.initials: S
authors.lastname: Fayyaz
authors.affiliation: H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Khalid Mohammed
authors.initials: KM
authors.lastname: Khan
authors.affiliation: H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Muhammad Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D024402:Carbonic Anhydrase II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002257:Carbonic Anhydrase Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D015394:Molecular Structure; D013329:Structure-Activity Relationship
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D007211:Indoles; D024402:Carbonic Anhydrase II
keywords: Bisindolylmethane; Carbonic anhydrase II; Docking; Enzyme inhibition; Sulfonamide