title: Antimicrobial and cytotoxic isohexenylnaphthazarins from Arnebia euchroma (Royle) Jonst. (Boraginaceae) callus and cell suspension culture.
abstract: The phytochemical investigation of the n-hexane extract from callus and cell suspension culture of Arnebia euchroma (Royle) Jonst. resulted in the isolation of nine isohexenylnaphthazarins: deoxyalkannin (1), alkannin (2), acetylalkannin (3), isobutyrylalkannin (4), &#946;-hydroxyisovalerylalkannin (5), 2''-(S)-&#945;-methylbutyrylalkannin (6), propionylalkannin (7), teracrylalkannin (8) and acetylshikonin (9). Their structures were determined by MS and NMR spectroscopy. Pigments 2&#8211;8 are isolated for the first time from Arnebia in vitro cultures, 4 and 7 are reported in the present work as novel metabolites within the Arnebia genus, while 9 is a known constituent of both natural roots and in vitro cultures of  A. euchroma. Moreover, methyl jasmonate and 1-monoglyceryl olate, palmitate and stearate are reported for the first time within the Boraginaceae family. The antimicrobial and cytotoxic activities of all isolated pigment compounds were tested, revealing a very interesting profile.
authors.affiliation: Department of Pharmacy, Institute of Pharmacognosy & Chemistry of Natural Products, University of Athens, Zografou 15771, Athens, Greece.
authors.forename: Harilaos
authors.initials: H
authors.lastname: Damianakos
authors.forename: Nadine
authors.initials: N
authors.lastname: Kretschmer
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Sykłowska-Baranek
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Pietrosiuk
authors.forename: Rudolf
authors.initials: R
authors.lastname: Bauer
authors.forename: Ioanna
authors.initials: I
authors.lastname: Chinou
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D028082:Boraginaceae / Q000737:chemistry*; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D009285:Naphthoquinones; D010936:Plant Extracts; C024720:isohexenylnaphthazarin