title: Antiprotozoal and cytotoxic naphthalene derivatives from Diospyros assimilis.
abstract: Chemical investigation of the roots of Diospyros assimilis had led to the isolation and characterization of six naphthalene derivatives, two 2-naphthaldehyes, namely 4-hydroxy-3,5-dimethoxy-2-naphthaldehyde 1, 4-hydroxy-5-methoxy-2-naphthaldehye 2, its related isomer 5-hydroxy-4-methoxy-2-naphthaldehyde 3 and three commonly occurring naphthoquinones, diospyrin 4, 8'-hydroxyisodiospyrin 5 and the simple monomer, plumbagin 6. Their chemical structures were established by detailed NMR investigations including 1H and 13C NMR, HSQC, HMBC and NOESY experiments. In addition, the naphthalene derivatives 1-5 were evaluated for their in vitro antiprotozoal activity against protozoan parasites belonging to the genera Trypanosoma, Leishmania and Plasmodium. Among the tested compounds, naphthaldehyde 1 showed moderate inhibition of the growth of the parasites, T. brucei, T. cruzi, L. donovani with IC50 values of 19.82, 12.28 and 38.78 microM and displayed cytotoxicity towards rat skeletal myoblasts (L-6 cells) with IC50 of 174.94 microM, while 2 and 3 were found to be comparatively less active to 1. The dimeric quinones 4 and 5 exhibited good activity against T. brucei and L. donovani with IC50 of 1.12 and 8.82 microM and 12.94 and 16.66 microM respectively.
authors.affiliation: Pharmacognosy and Phytochemistry Division, Department of Pharmaceutical Sciences, Andhra University, Visakhapatnam 530 003, Andhra Pradesh, India. ganapatyseru@gmail.com
authors.forename: S
authors.initials: S
authors.lastname: Ganapaty
authors.forename: P
authors.initials: P
authors.lastname: Steve Thomas
authors.forename: Gloria
authors.initials: G
authors.lastname: Karagianis
authors.forename: Peter G
authors.initials: PG
authors.lastname: Waterman
authors.forename: Reto
authors.initials: R
authors.lastname: Brun
mesh_terms: D000447:Aldehydes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D029788:Diospyros / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D007893:Leishmania donovani / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D051381:Rats; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: C515898:4-hydroxy-3,5-dimethoxy-2-naphthaldehyde; C515897:4-hydroxy-5-methoxy-2-naphthaldehyde; D000447:Aldehydes; D000981:Antiprotozoal Agents; D009281:Naphthalenes; D009285:Naphthoquinones; C031721:naphthalene; C043546:diospyrin; C014758:plumbagin