title: Direct modification of bioactive phenothiazines by exposure to laser radiation.
abstract: Whereas exposure of combinations of a phenothiazine and bacterium to incoherent UV increases the activity of the phenothiazine, exposure of the phenothiazine alone does not yield an increase of its activity. Because the laser beam energy is greater than that produced by the incoherent UV sources, exposure of phenothiazines to specific lasers may yield molecules with altered activities over that of the unexposed parent. Chlorpromazine, thioridazine and promethazine active against bacteria were exposed to two distinct lasers for varying periods of time. Absorption and fluorescence spectra were conducted prior to and post-exposure and the products of laser exposure evaluated for activity against a Staphylococcus aureus ATCC strain via a disk susceptibility assay. Exposure to lasers alters the absorption/fluorescence spectra of the phenothiazines; reduces the activity of thioridazine against the test bacterium; produces a highly active chlorpromazine compound against the test organism. Exposure of phenothiazines to lasers alters their structure that results in altered activity against a bacterium. This is the first report that lasers can alter the physico-chemico characteristics to the extent that altered bioactivity results. Exposure to lasers is expected to yield compounds that are difficult to make via chemical manipulation methods. A survey of selected patents of interest, even co-lateral for the subject of this article is shortly made.
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Laser Department, PO Box MG-36, Str Atomistilor nr 409, Magurele, Ilfov, Bucharest 077125, Romania. mihai.pascu@inflpr.ro
authors.forename: Mihail-Lucian
authors.initials: ML
authors.lastname: Pascu
authors.forename: Viorel
authors.initials: V
authors.lastname: Nastasa
authors.forename: Adriana
authors.initials: A
authors.lastname: Smarandache
authors.forename: Andra
authors.initials: A
authors.lastname: Militaru
authors.forename: Ana
authors.initials: A
authors.lastname: Martins
authors.forename: Miguel
authors.initials: M
authors.lastname: Viveiros
authors.forename: Mihai
authors.initials: M
authors.lastname: Boni
authors.forename: Ionut Relu
authors.initials: IR
authors.lastname: Andrei
authors.forename: Alexandru
authors.initials: A
authors.lastname: Pascu
authors.forename: Angela
authors.initials: A
authors.lastname: Staicu
authors.forename: Joseph
authors.initials: J
authors.lastname: Molnar
authors.forename: Seamus
authors.initials: S
authors.lastname: Fanning
authors.forename: Leonard
authors.initials: L
authors.lastname: Amaral
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D002626:Chemistry, Pharmaceutical; D002746:Chlorpromazine / Q000494:pharmacology / Q000528:radiation effects; D052978:Disk Diffusion Antimicrobial Tests; D055808:Drug Discovery; D053844:Lasers, Solid-State; D015394:Molecular Structure; D010330:Patents as Topic; D010640:Phenothiazines / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D011398:Promethazine / Q000494:pharmacology / Q000528:radiation effects; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013329:Structure-Activity Relationship; D013678:Technology, Pharmaceutical / Q000379:methods; D013881:Thioridazine / Q000494:pharmacology / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D010640:Phenothiazines; D011398:Promethazine; D013881:Thioridazine; D002746:Chlorpromazine