title: Antibacterial and antiviral naphthazarins from Maharanga bicolor.
abstract: Maharanga bicolor, Boraginaceae, is used in the Nepalese ethnomedicine for the treatment of several diseases. In the course of screening investigations the dichloromethane extract of the roots of Maharanga bicolor was found to inhibit the growth of gram positive bacteria. Bio-assay directed fractionation led to the isolation of five active naphthazarins, deoxyalkannin (1), alkannin (2), acetylalkannin (3), alkannin beta-hydroxyisovalerate (4) and alkannin beta-acetoxyisovalerate (5). Compounds 2-5 showed antibacterial activity against multi resistant human pathogenic Staphylococcus and Enterococcus species and 1, 4 and 5 showed antiviral activity against herpes simplex virus type-1.
authors.affiliation: Research Center for Applied Science and Technology, Tribhuvan University, Kathmandu, Nepal.
authors.forename: M
authors.initials: M
authors.lastname: Rajbhandari
authors.forename: T H
authors.initials: TH
authors.lastname: Schoepke
authors.forename: R
authors.initials: R
authors.lastname: Mentel
authors.forename: U
authors.initials: U
authors.lastname: Lindequist
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D000998:Antiviral Agents; D001412:Bacillus subtilis / Q000187:drug effects; D028082:Boraginaceae / Q000737:chemistry*; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D004285:Dogs; D016983:Enterococcus / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D018259:Herpesvirus 1, Human / Q000187:drug effects; D009980:Influenza A virus / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D009285:Naphthoquinones / Q000302:isolation & purification / Q000494:pharmacology*; D009390:Nepal; D010936:Plant Extracts / Q000737:chemistry; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D013210:Staphylococcus / Q000187:drug effects; D013329:Structure-Activity Relationship; D014709:Vero Cells
chemical_list: D000900:Anti-Bacterial Agents; D000972:Antineoplastic Agents, Phytogenic; D000998:Antiviral Agents; D009285:Naphthoquinones; D010936:Plant Extracts; D012997:Solvents