A computational insight into the photophysics of a potent UV absorber Tinuvin P: Critical evaluation of the role of charge transfer interaction and topological properties of the intramolecular hydrogen bonding

Paul, Bijan Kumar; Guchhait, Nikhil

doi:10.1016/j.comptc.2011.03.011

Cited by 24 publications

(7 citation statements)

References 77 publications

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“…Now, as we endeavor to frame an interpretation for the observed modulations on the emission profile of HM upon interaction with the studied lipids, and find a reasonable consistency between our steady-state and time-resolved data, it could be imperative to focus on hydrogen bonding property of HM, which could also be fruitful in assessing molecular interaction mechanism between the molecular probe and the lipids. [56][57][58][59][60][61][62][63][64] In some recent reports Zhao et al have demonstrated the crucial influences that intra-and inter-molecular hydrogen bonding interactions can exert on fluorescence properties of a fluorophore. [57][58][59][60][61][62][63][64][65] Both the intermolecular (I er MHB) and intramolecular (I ra MHB) hydrogen bonding can function as effective conduits to facilitate nonradiative deactivation of excited fluorophores.…”

Section: Elucidation Of the Drug Binding Sitementioning

confidence: 99%

Differential interactions of a biological photosensitizer with liposome membranes having varying surface charges

Paul

Guchhait

2012

Photochem Photobiol Sci

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The present work demonstrates the interaction of promising cancer cell photosensitizer, harmane (HM), with liposome membranes of varying surface charges, dimyristoyl-l-α-phosphatidylcholine (DMPC) and dimyristoyl-l-α-phosphatidylglycerol (DMPG). Electrostatic interaction of the cationic probe (HM) with the surface charges of the lipids is responsible for differential modulation of the spectral properties of the drug in different lipid environments. Estimation of partition coefficient (K(p) (±10%) = 5.58 × 10(4) in DMPC and 3.28 × 10(5) in DMPG) of HM between aqueous buffer and lipid phases reflect strong binding interaction of the drug with both the lipids. Evidence for greater degree of partitioning of HM into DMPG membrane compared to DMPC membrane has been deduced and further substantiated from experimental studies such as steady-state fluorescence anisotropy, micropolarity determination. The molecular modeling investigation by docking simulation coupled with fluorescence quenching experiment has been exploited to substantiate the location of drug at the lipid head-group region. Modulation of the dynamical properties of the drug within the lipid environments has also been addressed. Rotational relaxation dynamics studies unravel the impartation of a significant degree of motional restriction on the probe molecule within the lipids and reinforce the differential interactions of HM with the two lipid systems along the lines of other findings. Fluorescence kinetics studies reveal a faster association (in terms of apparent rate constants describing the process of interaction) of the drug with DMPG membrane compared to DMPC. This result is argued in connection with the electrostatic interaction between the drug and the liposome surface charges.

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Section: Elucidation Of the Drug Binding Sitementioning

confidence: 99%

Differential interactions of a biological photosensitizer with liposome membranes having varying surface charges

Paul

Guchhait

2012

Photochem Photobiol Sci

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“…When the solvent was changed to ethanol, LWE in CAAQ and DCAQ decreased greatly 40 . The substituent effect on ESIPT for AQs have been explained by nodal-plane model proposed in 1996 48 , which have also been widely explored and proved to be a reliable theory to study the ESIPT systems 49 – 51 . However, this model only qualitatively describes ESPIT process based on the molecular skeletons and functional groups, without the quantitative descriptions of the dual fluorescence distribution and energy barriers, limiting an accurate understanding of ESIPT process.…”

Section: Introductionmentioning

confidence: 99%

Combined TDDFT and AIM Insights into Photoinduced Excited State Intramolecular Proton Transfer (ESIPT) Mechanism in Hydroxyl- and Amino-Anthraquinone Solution

Zheng

Zhang

Zhao

2017

Sci Rep

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Time-dependent density functional theory (TDDFT) and atoms in molecules (AIM) theory are combined to study the photoinduced excited state intramolecular proton transfer (ESIPT) dynamics for eight anthraquinones (AQs) derivatives in solution. The calculated absorption and emission spectra are consistent with the available experimental data, verifying the suitability of the theory selected. The systems with the excited-state exothermic proton transfer, such as 1-HAQ, 1,5-DHAQ and TFAQ, emit completely from transfer structure (T), while the reactions for those without ESIPT including 1,4-DHAQ and AAAQ appear to be endothermic. Three reaction properties of three systems (1,8-DHAQ, DCAQ and CAAQ) are between the exothermic and endothermic, sensitive to the solvent. Energy scanning shows that 1,4-DHAQ and AAAQ exhibit the higher ESIPT energy barriers compared to 1-HAQ, 1,5-DHAQ and TFAQ with the “barrierless” ESIPT process. The ESIPT process is facilitated by the strengthening of hydrogen bonds in excited state. With AIM theory, it is observed that the change in electrons density ρ(r) and potential energy density V(r) at BCP position between ground state and excited state are crucial factors to quantitatively elucidate the ESIPT.

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“…Therefore, the nature of the photoexcited states of UV absorbers and their deactivation processes have been a subject of numerous investigations. [9][10][11][12][13][14][15][16][17] In most cases, sunscreens contain more than one UV absorber to cover a wide range of wavelengths. There may be stabilizing or destabilizing interactions in the mixture of several UV absorbers.…”

Section: Introductionmentioning

confidence: 99%

Photophysical properties of dioctyl 4-methoxybenzylidenemalonate: UV-B absorber

Oguchi-Fujiyama

Miyazawa

Kikuchi

et al. 2012

Photochem Photobiol Sci

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Dioctyl 4-methoxybenzylidenemalonate (DOMBM) is an effective stabilizer for photolabile 4-tert-butyl-4'-methoxydibenzoylmethane (BMDBM). DOMBM is superior to the most widely used UV-B absorber, octyl methoxycinnamate (OMC), at preserving its UV-B absorbance in the presence of BMDBM. The energy levels of the lowest excited singlet (S(1)) and triplet (T(1)) states of DOMBM were determined by measuring fluorescence and phosphorescence spectra in ethanol at 77 K. The energy level of the T(1) state of DOMBM is lower than that of BMDBM and is higher than that of OMC. The triplet-triplet energy transfer from BMDBM to DOMBM was demonstrated by measuring the electron paramagnetic resonance (EPR) and time-resolved phosphorescence spectra. The phosphorescence and EPR signals of DOMBM are too weak to be observed through the direct excitation in ethanol at 77 K. The phosphorescence spectrum was observed by using external heavy atom effects of ethyl iodide. The EPR spectrum was observed by using benzophenone as a triplet sensitizer. The fluorescence quantum yield of DOMBM is small in ethanol at room temperature. Only the fast component, due to the heat released from the excited state of DOMBM, was observed in the time-resolved thermal lensing experiments at room temperature. These results show that the quantum yield of the S(1) → T(1) intersystem crossing is negligible and the deactivation process is predominantly internal conversion to the ground state for DOMBM.

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A computational insight into the photophysics of a potent UV absorber Tinuvin P: Critical evaluation of the role of charge transfer interaction and topological properties of the intramolecular hydrogen bonding

Cited by 24 publications

References 77 publications

Differential interactions of a biological photosensitizer with liposome membranes having varying surface charges

Differential interactions of a biological photosensitizer with liposome membranes having varying surface charges

Combined TDDFT and AIM Insights into Photoinduced Excited State Intramolecular Proton Transfer (ESIPT) Mechanism in Hydroxyl- and Amino-Anthraquinone Solution

Photophysical properties of dioctyl 4-methoxybenzylidenemalonate: UV-B absorber

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