Chemiluminescent activation of the antiviral activity of hypericin: a molecular flashlight.

Fluorescence upconversion measurements of hypericin and its methylated analog, O-hexamethoxyhypericin, which possesses no labile protons, confirm excited-state proton (or hydrogen atom) transfer as the primary photophysical event in hypericin. The presence of a rising component in the time-resolved fluorescence of hypericin and the absence of such a component for the hexamethoxy analog are consistent with our assignment of excited-state proton or atom transfer as the primary photophysical process in the light-activated antiviral compound, hypericin. The results using the fluorescence upconversion technique, which detects only emission from the excited state, are in good agreement with our previous transient absorbance measurements. The results are also consistent with a heterogeneous ground state of hypericin.

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“…28 We have proposed a chemiluminescent means of activating the pharmacological activity of hypericin and its analogs. 29 …”

Section: Introductionmentioning

confidence: 99%

Confirmation of Excited-State Proton Transfer and Ground-State Heterogeneity in Hypericin by Fluorescence Upconversion

et al. 1997

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“…A majority of the herb's antidepressant activity have recently been attributed to hyperforin and adhyperforin, and these compounds also possess antibacterial and cell growth inhibitory activity (1)(2)(3)14). The naphthodianthrone compounds, hypericin and its major metabolite pseudohypericin, have been shown to possess potent antiviral and cytotoxic properties upon light exposure (10)(11)(12)15).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Light-Sensitive Cytotoxicity of Hypericum perforatum Extracts, Fractions, and Pure Compounds

Schmitt

Liu

Murphy

et al. 2006

J. Agric. Food Chem.

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Hypericum perforatum (Hp) is known for possessing antidepressant and antiviral activities. Despite its use as an alternative to conventional antidepressants, the identification of the cytotoxic chemicals derived from this herb is incomplete. In this study, the cytotoxicity of Hp extracts prepared in solvents ranging in polarity, fractions of one extract, and purified compounds were examined in three cell lines. All extracts exhibited significant cytotoxicity; those prepared in ethanol (no hyperforin, 3.6 μM hypericin, and 134.6 μM flavonoids) showed between 7.7 and 77.4% cell survival (p < 0.0001 and 0.01), whereas the chloroform and hexane extracts (hyperforin, hypericin, and flavonoids not detected) showed approximately 9.0 (p < 0.0001) and 4.0% (p < 0.0001) survival. Light-sensitive toxicity was observed primarily with the ethanol extracts sequentially extracted following removal of material extracted in either chloroform or hexane. The absence of light-sensitive toxicity with the Hp extracts suggests that the hypericins were not playing a prominent role in the toxicity of the extracts.

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“…Our group has characterized the antiviral activity of hypericin using equine infectious anemia virus (EIAV) as a retroviral model of HIV. [31][32][33][34][35][36][37][38] EIAV is a well-suited model for for studies of antiviral agents effective against HIV since it is an enveloped lentivirus that is structurally, genetically, and antigenically related to HIV. [39][40][41] Our studies have demonstrated that hypericin, in the presence of ambient room light, reduces the infectivity of cell-free stocks of EIAV by 99.99%.…”

Section: Virus Replication and Antiviral Drugsmentioning

confidence: 99%

“…42,43 More recently, we have devised a strategy to place in the proximity of hypericin a chemiluminescent light source so that photodynamic therapy can be extended to all regions of the body. 33 Examination of the structural and chemical basis for light-activated virucidal activity has resulted in new concepts of how these compounds may inactivate the virus. [34][35][36] These studies represent the fruit of a successful interaction of synthetic chemistry with molecular virology and physical chemistry and illustrate how such interactions may lead to novel antiviral therapies.…”

Section: Virus Replication and Antiviral Drugsmentioning

confidence: 99%

Research at the Interface between Chemistry and Virology: Development of a Molecular Flashlight

et al. 1996

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Although industrial researchers have been involved in interdisciplinary studies pertaining to virology for several decades, the participation of academic chemists has been significantly increased owing to the importance of HIV (human immunodeficiency virus), the virus which leads to the onset of AIDS (acquired immune deficiency syndrome). The Center for Disease Control estimates that almost 20 million people have been infected by HIV worldwide. The compelling need for effective antiviral therapies for HIVinfected persons, together with rapid advances in understanding the molecular mechanisms of virus replication, has resulted in an explosion of interest in antiviral agents and approaches to antiviral therapies DisciplinesChemistry | Environmental Chemistry | Inorganic Chemistry | Organic Chemistry | Other Chemistry | Polymer Chemistry CommentsReprinted (adapted) with permission from Chemical Reviews, 96(1); 523-536.

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Chemiluminescent activation of the antiviral activity of hypericin: a molecular flashlight.

Cited by 95 publications

References 33 publications

Confirmation of Excited-State Proton Transfer and Ground-State Heterogeneity in Hypericin by Fluorescence Upconversion

Confirmation of Excited-State Proton Transfer and Ground-State Heterogeneity in Hypericin by Fluorescence Upconversion

Evaluation of the Light-Sensitive Cytotoxicity of Hypericum perforatum Extracts, Fractions, and Pure Compounds

Research at the Interface between Chemistry and Virology: Development of a Molecular Flashlight

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