Photophysical, Electrochemical, and Theoretical Study of Protriptyline in Several Solvents

García, Carmina Saldaña; Oyola, Rolando; Piñero, Luis; Cruz, Nadya; Alejandro, Félix; Arce, Rafael; Nieves, Ileana

doi:10.1021/jp0257855

Cited by 10 publications

(23 citation statements)

References 24 publications

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“…In line with these experiments, the tricyclic antidepressants (TCAs) - Imipramine (IPA), desimipramine (DIPA) and clomipramine (CIPA) - photophysical properties were studied in different solvents [19]. It was shown that the primary transient intermediates produced by 266 nm high-intensity laser photolysis are the solvated electron and the corresponding radical cation, consistent with the results reported in [18]. Results reported in [20] show that exposure to UV of protriptyline hydrochloride (PTL) 10 −3 M solutions in phosphate-buffered saline, resulted in a mixture of at least five product which caused red blood cell lysis but required water for their formation and were stable for at least one week.…”

Section: Introductionsupporting

confidence: 73%

“…The protriptyline hydrochloride (PTL-HCl) showed (by 266 nm nanosecond laser flash photolysis) the presence of the triplet−triplet transient intermediate at low laser beam intensities and two transient intermediates (the solvated electron and the radical cation) at high laser beam energy. The authors considered that the PTL-HCl triplet state may be associated with the in vivo phototoxic effects of this drug [18]. In line with these experiments, the tricyclic antidepressants (TCAs) - Imipramine (IPA), desimipramine (DIPA) and clomipramine (CIPA) - photophysical properties were studied in different solvents [19].…”

Section: Introductionmentioning

confidence: 99%

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Exposure of Chlorpromazine to 266 nm Laser Beam Generates New Species with Antibacterial Properties: Contributions to Development of a New Process for Drug Discovery

et al. 2013

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IntroductionPhenothiazines when exposed to white light or to UV radiation undergo a variety of reactions that result in degradation of parental compound and formation of new species. This process is slow and may be sped up with exposure to high energy light such as that produced by a laser.MethodsVarying concentrations of Chlorpromazine Hydrochloride (CPZ) (2–20 mg/mL in distilled water) were exposed to 266 nm laser beam (time intervals: 1–24 hrs). At distinct intervals the irradiation products were evaluated by spectrophotometry between 200–1500 nm, Thin Layer Chromatography, High Pressure Liquid Chromatography (HPLC) - Diode Array Detection, HPLC tandem mass spectrometry, and for activity against the CPZ sensitive test organism Staphylococcus aureus ATCC 25923.ResultsCPZ exposure to 266 nm laser beam of given energy levels yielded species, whose number increased with duration of exposure. Although the major species produced were Promazine (PZ), hydroxypromazine or PZ sulfoxide, and CPZ sulfoxide, over 200 compounds were generated with exposure of 20 mg/mL of CPZ for 24 hrs. Evaluation of the irradiation products indicated that the bioactivity against the test organism increased despite the total disappearance of CPZ, that is due, most probably, to one or more new species that remain yet unidentified.ConclusionsExposure of CPZ to a high energy (6.5 mJ) 266 nm laser beam yields rapidly a large number of new and stable species. For biological grade phenothiazines (in other words knowing the impurities in the samples: solvent and solute) this process may be reproducible because one can control within reasonably low experimental errors: the concentration of the parent compound, the laser beam wavelength and average energy, as well as the duration of the exposure time. Because the process is “clean” and rapid, it may offer advantages over the pyrogenically based methods for the production of derivatives.

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Section: Introductionsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Exposure of Chlorpromazine to 266 nm Laser Beam Generates New Species with Antibacterial Properties: Contributions to Development of a New Process for Drug Discovery

et al. 2013

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“…The peak at 322 nm was assigned to an n-Π* transition, as previously reported for the phenothiazine derivatives. [11]…”

Section: Resultsmentioning

confidence: 99%

“…This is also consistent with other PH derivatives, which also have more planar excited states. [11] The PM3 calculations predict triplet-triplet bands at 346 and 498 nm, all with relative low molar absorption coefficient. The agreement with the experimental values is good, although, these theoretical excited state calculations suffer from large spin contamination.…”

Section: Resultsmentioning

confidence: 99%

Spectroscopic and electrochemical properties of 2-aminophenothiazine

Piñero¹,

Calderón²,

Rodríguez³

et al. 2008

Journal of Photochemistry and Photobiology A: Chemistry

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Phenothiazines derivatives are versatile compounds that are used in many fields, depending on the type and position of the substitution on the parent molecule. The photochemical, photophysical and electrochemical properties of several phenothiazine derivatives have been previously reported in detail. However, no reports have been presented for 2-aminophenothiazine (APH), a candidate that provides for the further chemical modification and the introduction of specific substituents. In this work, the photophysical and electrochemical properties of APH were measured in acetonitrile. The APH ground state absorption and fluorescence spectrum (φf < 0.01) are similar to the corresponding that of PH parent molecule. A mono exponential decay fluorescence lifetime of 0.65 ns was determined for APH in acetonitrile. Characterization of the 355 nm nanosecond laser flash photolysis transient species reveals the presence of the triplet-triplet transient intermediate with a high intersystem crossing quantum yield (φT = 0.72 ± 0.07), indicating that the APH main excited state deactivation channel is intersystem crossing. The oxidation potential of APH is lower than phenothiazine parent molecule ((0.38 V vs 0.69 V vs Ag/AgCl(sat)). Altogether, these results show that APH has photochemical and photophysical properties similar to the phenothiazine parent molecule, but with the possibility of providing an amino functionality at 2-position for further chemical modification.

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“…Theoretical calculations. All geometry optimizations were initially performed at the semiempirical level with the Polak‐Ribiere conjugated gradient protocol with 1 × 10 −5 convergence limit and 0.01 kcal (Å mol −1 ) rms limit, as previously described (28). Density functional theory (DFT) with B3LYP/6–31 G(d) was used for the optimization refinement and the calculation of the dissociation energies of solvents and TCA molecules, according to : where Δ H f ( X – Y ) is the formation enthalpy of the species XY and D ( X – Y ) is the dissociation enthalpy of the X – Y bond.…”

mentioning

confidence: 99%

Photodegradation of 2‐chloro Substituted Phenothiazines in Alcohols

García

Piñero

Oyola

et al. 2009

Photochem & Photobiology

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The mechanisms that trigger the phototoxic response to 2-chlorophenothiazine derivatives are still unknown. To better understand the relationship between the molecular structure of halogenated phenothiazines and their phototoxic activity, their photophysics and photochemistry were studied in several alcohols. The photodestruction quantum yields were determined under anaerobic conditions using monochromatic light (313 nm). Absorption-and emission-spectroscopy, 1 H-and 13 C-NMR and GC-MS were used to characterize the photoproducts and reference compounds. An electron transfer mechanism had been previously proposed by Bunce et al. (J. Med. Chem. 22,[202][203][204] to explain the large difference between the photodestruction quantum yield of 2-chlorpromazine (u = 0.46) and 2-chlorphenothiazine (u = 0.20). According to these authors, the alkylamino chain transfers an electron to the phenothiazine moiety. Our results demonstrate that this mechanism is incorrect, because the photodestruction quantum yields of all chlorinated derivatives of this study are the same under the same conditions of solvent and irradiation wavelength. The quantum yield has no dependence on the 10-substituent, but it depends on the solvent. The percentage of each photoproduct, on the other hand, strongly depends on that substituent, but not very much on the solvent. Finally, it is demonstrated that the phototoxic effect of chlorinated phenothiazines is not related to the photodechlorination, although both processes share the same transient.

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Photophysical, Electrochemical, and Theoretical Study of Protriptyline in Several Solvents

Cited by 10 publications

References 24 publications

Exposure of Chlorpromazine to 266 nm Laser Beam Generates New Species with Antibacterial Properties: Contributions to Development of a New Process for Drug Discovery

Exposure of Chlorpromazine to 266 nm Laser Beam Generates New Species with Antibacterial Properties: Contributions to Development of a New Process for Drug Discovery

Spectroscopic and electrochemical properties of 2-aminophenothiazine

Photodegradation of 2‐chloro Substituted Phenothiazines in Alcohols

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