Analysis of non-linear optical properties of phytochemical photosensitizers in cancer photodynamic therapy by quantum computational

• Published in: Results in Chemistry 2024-06, Vol.8, p.101580, Article 101580
• Main Authors: Aneesa, V.M., Safna Hussan, K.P., Lekshmi, S., Babu, Thekkekara D., Muraleedharan, K.
• Format: Article
• Language: English
• Subjects: Non-linear optical properties; Photodynamic therapy; Photosensitizers; Phytochemicals; Quantum computational calculations
• ISSN: 2211-7156; 2211-7156
• DOI: 10.1016/j.rechem.2024.101580

[Display omitted] •Photodynamic therapy (PDT) leverages reactive oxygen species (ROS) from photosensitizers derived from plants for safer cancer treatment.•Nonlinear optics (NLO) enhance photosensitizer efficacy, crucial for optimizing PDT.•Integration of computational studies helps understand electronic properties and reactivity of phytochemicals in the reported polyherbal formulation, aiding their optimization for PDT.•Interdisciplinary approach combining quantum chemistry, photophysics, and cancer therapeutics aims to design next-generation photosensitizers with improved phototoxicity and tumor-targeting capabilities. Photodynamic therapy (PDT) is based on the reactive oxygen species (ROS) generated by light-activated photosensitizers in the presence of oxygen. Phytochemicals are promising natural photosensitizers, offering a potentially less toxic alternative for cancer treatments. Nonlinear optics (NLO) phenomena, such as second-harmonic generation (SHG), third-harmonic generation (THG), and two-photon absorption (TPA), can enhance light interaction, benefiting photosensitizing applications in PDT. Analyzing the NLO properties of phytochemicals can optimize their use in PDT by improving photosensitizer performance and efficacy. This study aims to examine the NLO properties of selected phytochemicals in a reported polyherbal formulation to understand their potential as effective photosensitizers in PDT, thereby advancing cancer treatment options. Quantum computational calculations were conducted at the B3LYP/6311 G++(d,p) level of theory to unveil crucial information about structural geometry and nonlinear optical properties. The bandgap of aloe emodin, emodin, curcumin, scopoletin berberine, furanocoumarin, rubiadin are 3.279 eV, 3.395 eV, 3.247 eV, 3.930 eV, 2.878 eV, 4.463 eV and 3.546 eV, respectively. The results highlight berberine as the most reactive compound, demonstrating high softness and low hardness. Curcumin and furanocoumarin exhibit distinct electron-donating and accepting tendencies, respectively. In the MESP map of furanocoumarin, scopoletin, and rubiadin the electro-negative region is highly oriented around the ketone group (=O) and partially at another O atom in the pentagon. The compensating electropositive charge was distributed elsewhere. In aloe emodin, emodin, and curcumin the electronegativity was distributed around the ketone group while high electropositivity was observed around the substituted hydroxyl functional groups. In