Hydroxylated anthraquinones produced by Geosmithia species

Abstract

Geosmithia fungi are little known symbionts of bark beetles. Secondary metabolites of lilac colored species G. lavendula and other nine Geosmithia species were investigated in order to elucidate their possible role in the interactions of the fungi with environment. Hydroxylated anthraquinones (yellow, orange, and red pigments), were found to be the most abundant compounds produced into the medium during the submerged cultivation. Three main compounds were identified as 1,3,6,8-tetrahydroxyanthraquinone (1), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 2), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (3). Compounds 2 and 3 (representing the majority of produced metabolites) inhibited the growth of G+-bacteria Staphylococcus aureus and Bacillus subtilis with minimum inhibitory concentration of 64-512 microg/mL. Anti-inflammatory activity detected as inhibition of cyclooxygenase-2 was found only for compound 3 at 1 and 10 microg/mL. Compound 2 interfered with the morphology, compound 3 with cell-cycle dynamics of adherent mammalian cell lines.

High-performance liquid chromatography–off line mass spectrometry analysis of anthraquinones produced by Geosmithia lavendula

“…Three anthraquinone standards, i.e. 1,3,6,8-tetrahydroxyanthraquinone (7), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 5), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (4) were isolated from fermentation broth of G. lavendula as described previously [10]. Briefly, fermentation broth of G. lavendula was centrifuged and three times extracted with equal volume of ethyl acetate/acetic acid (20:1, v/v).…”

“…Crude pigments were extracted as described previously [10]. Prior to HPLC analysis dry crude extract was reconstituted in methanol containing 1% TFA (v/v).…”

“…The UV/VIS spectra of AQ standards (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) were monitored in methanol in range of 190-700 nm using Shimadzu multipurpose recording spectrophotometer MPS-2000 equipped with graphic printer PR-3. Table 1.…”

“…During the screening of secondary metabolites of this fungus, three anthraquinones 1,3,6,8-tetrahydroxyanthraquinone (7), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 5), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (4) were identified as the most abundant compounds produced into the medium during the submerged cultivation [10].…”

“…As found previously, biological activity assay of 4 performed on mammalian cell lines suggested specific modulation of cell physiology which led to alterations in the dynamics of the cell cycle. The most obvious phenotype was accumulation of abnormal metaphase-anaphase transition mitotic phase, which is normally only transient and rare [10]. For the method development the 14-day-old fermentation broth of G. lavendula was used as a standard.…”