2134-99-8Relevant academic research and scientific papers
Visible-light photochemistry and phototoxicity of thiarubrines
Page, Jonathan E.,Block, Eric,Towers, G. H. Neil
, p. 159 - 165 (1999)
Thiarubrines, a group of intensely red, sulfur-containing pigments produced by asteraceous plants, are photolabile, yielding thiophenes and elemental sulfur upon exposure to UV or visible light. The mechanism of this light-induced conversion for thiarubrines A (1a), B (1b) and D (1c), isolated from the roots of Ambrosia chamissonis (Asteraceae), was investigated. Visible-light irradiation of thiarubrines resulted in the formation of novel 2,6-dithiabicyclo[3.1.0]hex-3-ene polyyne photointermediates (photosulfides) that rapidly undergo desulfurization to yield thiophenes. Six photosulfides, photosulfides 3a and 3a′ from thiarubrine A (1a), photosulfides 3b and 3b′ from thiarubrine B (1b) and photosulfides 3c and 3c′ from thiarubrine D (1c) were characterized. Thiarubrine photointermediates are short-lived and unstable, with the photosulfides formed from thiarubrine A having a half-life of 12.3 min at room temperature. While the immediate fate of the extruded sulfur is unknown, we identified cyclooctasulfur (S8) in photolysis solutions of thiarubrine A using electron impact mass spectrometry. Visible-light irradiation of Candida albicans cell suspensions treated with thiarubrine A led to a 99% decrease in cell viability, suggesting that the photosulfides, or other molecules generated by the exposure of thiarubrines to light, have significant toxicity.
Two dithiacyclohexadiene polyacetylenes from Chaenactis douglasii and Eriophyllum lanatum
Norton,Finlayson,Towers
, p. 356 - 357 (1985)
We have isolated two dithiapolyacetylenes from the roots of Chaenactis douglasii and from the plant roots as well as root cultures of Eriophyllum lanatum, namely 1-(2-methylethyn)-4-(hex-1,3-diyn-4-ene)-2,3-dithiacyclohexa-4,6-diene, and 1-(4-methylbut-1,3-diyn)-4-(but-1-yn-3-ene)-2,3-dithiacyclohexa-4,6-diene. We propose the trivial names thiarubrine A and thiarubrine B for these compounds.
