Members of the group:

Research Projects

Antiretroviral Agents

The chemical and pharmacological properties of hypericin, a naphtodianthrone derivative isolated by us from the plant of the genus Hypericum and synthesized in our laboratory, were investigated. Hypericin inactivates virions directly, interferes with the production of viral particles and with de-novo infections of cells (with Prof. David Lavie, Organic Chemistry, W.I.S., and Dr. Gad Lavie, Tel-Hashomer Hospital). This compound shows potent antiviral activity, and its clinical applications as a potential AIDS and hepatitis C cure are being studied.

New light stable helianthrone derivatives were prepared, and have proven to have photosensitizing potential to be used for photodynamic therapy (PDT) as anti-cancer agents (with Prof. Yona Kesari, Tel Aviv University, and Dr. Gad Lavie, Tel-Hashomer Hospital).

Recent publications

G. Siboni, H. Weitman, D. Freeman, Y. Mazur, Z. Malik, and B. Ehrenberg, "The correlation between hydrophilicity of hypericins and helianthrone: internalization mechanisms, subcellular distribution and photodynamic action in colon carcinoma cells", Photochem. Photobiol. Sci. 1, 483-491 (2002)

S. Rahimipour, C. Palivan, D. Freeman, F. Barbosa, M. Fridkin, L. Weiner, Y. Mazur, and G. Gescheidt, "Hypericin derivatives: Substituent effects on radical-anion formation", Photochem. Photobiol. 74, 149-156 (2001)

S. Rahimipour, I. Bilkis, V. Peron, G. Gescheidt, F. Barbosa, Y. Mazur, Y. Koch, L. Weiner, and M. Fridkin, Generation of free radicals by emodic acid and its [D-Lys(6)]GnRH-conjugate, Photochem. Photobiol. 74, 226-236 (2001)

D. Freeman, L. Konstantinovskii and Y. Mazur. The structure of hypericin in solution. Searching for hypericin 1,6 tautomer. Photochem. Photobiol. 74, 206-216 (2001).

H. Weitmann, M. Roslaniec, A. Frimer, M. Affri, D. Freeman and Y. Mazur. Solvatochormic effects in the electronic ab sorption and NMR spectra in organic solvents and in lipid bilayers. Photochem. Photobiol. 73, 110 (2001).[read abstract]

T. Gilat, G.J. Sonigen, Y. Mazur, A.Laken-Frenkel, R. Rosenberg, Z. Halpern and F.M. Konikoff. Fatty acid, bile acid conjugates (FABACS). New molecules for the prevention of cholesterol crystallization in bile. GUT 48, 75 (2001).[read abstract]

M. Roslaniec, C. Weitman, D. Freeman, Y. Mazur and B. Ehrenberg. Liposome binding constants and singlet oxygen quantum yields of hypericin, tetrahydroxy helianthrone and their derivatives; studies in organic and biological media. J. Photochem. Photobiol. 57, 149 (2000).[read online]

A. Prince, P. Pascual, D. Meruelo, L. Liebes, Y. Mazur, D. Dubovi, E. Mandel and D. Lavie. Strategies for evaluation of envoloped virus inactivation in red cell concentrates using hypericin activation virus. Photochem. Photobiol. 71, 110 (2000).[read abstract]

G.Lavie, Y. Kaplinsky, A. Torne, I. Eizeman, D. Meruelo, Y. Mazur and M. Mandel. A photodynamic pathway to apoptosis and necrosis induced by dimethyl tetrahydroxy helianthrone and hypericin in leukemikc cells: possible relevance to photodynamic therapy. Br. J. Cancer 79, 423 (1999).[read abstract]

L. Weiner, E. Roth, Y. Mazur and I. Silman. Targeted crosslinking of a moeltn globule form of acetylcholinesterase. Biochemistry 38, 11401 (1999).[read online]

M. Mylrajan, P. Hildebrandt and Y. Mazur. Vibrational spectroscopy of hypericin, its sodium salt and pyridium complex. J. Mol. Struct. 407, 5 (1997).[read online]

F. Gerson, G. Gescheidt, P. Haring, Y. Mazur, D. Freeman, H. Spreitzer and J. Daub. Electron-acceptor properties of hypericin and its salts: an ESR/ENDOR and electrochemical study. J. Am. Chem. Soc. 117, 11861 (1995).[read abstract]

G. Lavie, Y. Mazur, D. Lavie and D. Meruelo. The chemical and biological properties of hypericin - a compound with a broad spectrum of biological activities. Med. Res. Rev. 15, 111 (1995).[read abstract]

G. Lavie, Y. Mazur, D. Lavie, A.M. Prince, D. Pascal, L. Liebes, B. Levin and D. Meruelo. Hypericin as an inactivator of infectious viruses in blood components. Transfusion 34, 392 (1995).[read abstract]

D. Freeman, F. Frolow, E. Kapinus, D.Lavie, G. Lavie, D. Meruelo and Y. Mazur. Acidic properties of hypericin and its octahydroxy analogue in the ground and excited state. J. Chem. Soc. Chem. Commun. 891 (1994). [read abstract]

D. Freeman, E. Kapinus, D. Lavie, G. Lavie, D. Meruelo and Y. Mazur. Photosensitization of the antivirally active hypericin complexes with albumin. Polish J. Chem. 68, 1435 (1994).[read abstract]