Theoretical insights on flavanones as antioxidants and UV filters: A TDDFT and NLMO study

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 170; pp. 286 - 294
• Main Authors: Ajmala Shireen, P., Abdul Mujeeb, V.M., Muraleedharan, K.
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.05.2017; Elsevier BV
• Subjects: Absorption; Aging; Aging (natural); Alpinetin; Antioxidants; Antioxidants - chemistry; Computer applications; Conjugation; Density functional theory; Filters; Flavanones; Flavanones - chemistry; Flavonoids; Magnetic Resonance Spectroscopy; Models, Theoretical; Organic chemistry; Pinocembrin; Pinostrobin; Quantum chemistry; Quantum Theory; Quercetin; Skin cancer; Sun screens; Sunburn; Sunscreening Agents - chemistry; Sunscreens; Thermodynamics; Ultraviolet radiation; Ultraviolet Rays; UV filter; Zingiberaceae - chemistry; Zingiberaceae - metabolism; Flavanones; UV filter; Pinocembrin; Pinostrobin; Alpinetin
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2017.04.021

UV radiations can cause several irritations to the skin like sunburn, photo aging and even skin cancer. Sunscreens are widely used to protect the skin against these harmful radiations. One of the ingredients present in these sunscreens are organic molecules capable of absorbing these harmful radiations. Recently, the search is on for antioxidant molecules which can act as UV filters as they can facilitate photo protection. In this study, a computational investigation based on density functional theory (DFT) is attempted on flavanones namely pinocembrin, pinostrobin and alpinetin found in Boesenbergia pandurata. Several quantum chemical descriptors are computed to understand the antioxidant potentiality of these molecules. Quantum chemical descriptors of these flavanone molecules are found to be comparable to that of well-known anti-oxidant quercetin. UV response of these molecules are studied using time dependent density functional theory (TD-DFT) formalism and by means of natural bond orbital (NBO) theory. It could be seen that these molecules exhibit a broad absorption in the UV region 270–390nm. This falls exactly in the region of harmful UVB and UVA radiation. Thus, these molecules have the potential to absorb the harmful UV radiation. From NLMO cluster studies, the orbital contribution to absorption is explained. In flavanones, unlike other classes of flavonoids, there is a discontinuity in the electron conjugation due to the absence of C2C3 double bond. This might be the key structural feature that leads to the absorption of these molecules to be centered around the UV region. These molecules can thus be treated as promising candidates for antioxidant UV filters in sunscreens. [Display omitted] •Search for antioxidant molecules which can act as UV filters•A computational investigation based on DFT is attempted on flavanones•UV response of these molecules are studied using TD-DFT formalism•Observed that these molecules have the potential to absorb the harmful UV radiation•Can be used as promising candidates for antioxidant UV filters in sunscreens