Varacin Explained

Varacin is a bicyclic organosulfur compound originally found in marine Ascidiacea from the Polycitor genus.^[1] It contains an unusual pentathiepin ring which reacts with DNA, and varacin and synthetic analogues have been investigated for their antimicrobial and antitumour properties.^{[2] [3]} Because of its potent biological activity and unusual and challenging ring system, it has been a popular target of efforts toward its total synthesis.^{[4] [5] [6]}

Notes and References

1. Makarieva TN, Stonik VA, Dmitrenok AS, Grebnev BB, Isakov VV, Rebachyk NM, Rashkes YW . Varacin and three new marine antimicrobial polysulfides from the far-eastern ascidian Polycitor sp . Journal of Natural Products . 58 . 2 . 254–8 . February 1995 . 7769392 . 10.1021/np50116a015 .
2. Greer A . On the origin of cytotoxicity of the natural product varacin. A novel example of a pentathiepin reaction that provides evidence for a triatomic sulfur intermediate . Journal of the American Chemical Society . 123 . 42 . 10379–86 . October 2001 . 11603989 . 10.1021/ja016495p .
3. Brzostowska EM, Greer A . The role of amine in the mechanism of pentathiepin (polysulfur) antitumor agents . Journal of the American Chemical Society . 125 . 2 . 396–404 . January 2003 . 12517151 . 10.1021/ja027416s .
4. Behar V, Danishefsky SJ . 1993-07-01. Total synthesis of the novel benzopentathiepin varacinium trifluoroacetate: the viability of "varacin-free base". Journal of the American Chemical Society. 115. 15. 7017–7018. 10.1021/ja00068a087. 0002-7863.
5. Ford PW, Narbut MR, Belli J, Davidson BS . 1994-10-01. Synthesis and Structural Properties of the Benzopentathiepins Varacin and Isolissoclinotoxin A. The Journal of Organic Chemistry. 59. 20. 5955–5960. 10.1021/jo00099a026. 0022-3263.
6. Toste FD, Still IW . 1995-07-01. A New Route to the Synthesis of the Naturally Occurring Benzopentathiepin Varacin . Journal of the American Chemical Society . 117 . 27 . 7261–7262 . 10.1021/ja00132a033 .