Position Impact of Hydroxy Groups on Spectral, Acid–Base Profiles and DNA Interactions of Several Monohydroxy Flavanones

Structure-related biological activities of flavanones are still considered largely unexplored. Since they exhibit various medicinal activities, it is intriguing to enter deeper into their chemical structures, electronic transitions or interactions with some biomolecules in order to find properties that allow us to better understand their effects. Little information is available on biological activity of flavanone and its monohydroxy derivatives in relation to their physicochemical properties as spectral profiles, existence of protonated/deprotonated species under pH changes or interaction with Calf Thymus DNA. We devoted this work to research demonstrating differences in the physicochemical properties of the four flavanones: flavanone, 2-hydroxyflavanone, 6-hydroxyflavanone and 7-hydroxyflavanone and linking them to their biological activity. Potentiometric titration, UV–Vis spectroscopy were used to investigate influence of pH on acid–base and spectral profiles and to propose the mode of interaction with DNA. Cyclic voltammetry was applied to evaluate antioxidant potentiality and additionally, theoretical DFT(B3LYP) method to disclose electronic structure and properties of the compounds. Molecular geometries, proton affnities and pKa values have been determined. According to computational and cyclic voltammetry results we could predict higher antioxidant activity of 6-hydroxyflavanone with respect to other compounds. The values of Kb intrinsic binding constants of the flavanones indicated weak interactions with DNA. Structure–activity relationships observed for antioxidant activity and DNA interactions suggest that 6-hydroxyflavanone can protect DNA against oxidative damage most effectively than flavanone, 2-hydroxyflavanone or 7-hydroxyflavanone

DNA binding properties of 2ʹ-hydroxyflavanon and SCHIFF base derivative

Flavanoids a class of plant and fungus secondary metabolites. 2ʹ-Hydroxyflavanone was previously isolated from Mimosa pudica(L.) whole plant and was found to exhibit anti-inflammatory effects in vitro and binding with calf timus DNA. There are also reports on anti-inflammatory properties of compounds bearing flavanone/chromone nucleus. The aim of this work was to develop a synthesis of new azomethine compounds derived from flavanones, to examine their spectroscopic properties and interaction with DNA. 2ʹ-Hydroxyflavanone and thiocarbohydrazide were used as substrates in the synthesis. The obtained products were analyzed by 1H NMR spectroscopy, UVVis. Ultraviolet spectroscopy was used to analyze the chemical-physical properties. Mechanism of interaction of bioactive 2ʹ-hydroxyflavanone with calf thymus deoxyribonucleic acid (DNA) was studied employing UV absorption. 2ʹ-Hydroxyflavanon and 2ʹHFTCH are photostable in DMSO. The interaction of 2ʹ-hydroxyflavanone and its derivative occurs by the mechanism of intercalation. The change in the structure of the 2ʹ-hydroxyflavanone molecule by Schiff base modification leads to an increase in DNA-binding properties. High binding ability of 2ʹ-hydroxyflavanone with DNA may be useful for development of new anti-inflammatory and antimicrobial remedies.Флаваноиды – крупнейший класс растительных полифенолов. 2ʹ-Гидроксифлаванон относится к производным флавона и первоначально был выделен из растения мимоза пугливая (Mimosa pudica). Данное химическое соединение обладает широким спектром биологической активности, в том числе и способностью к связыванию с ДНК. Нами изучены физико-химические свойства 2ʹ-гидроксифлаванона и его производного на основе модификации Шиффа, а также механизмы их взаимодействия с ДНК. Качественный анализ проведен с помощью ядерного магнитного резонанса. Для анализа стабильности химической структуры производного 2ʹ-гидроксифлаванона на основе модификации Шиффа использовали ультрафиолетовую спектроскопию. 2ʹ-Гидроксифлаванон и его производ-ное фотостабильны в диметилсульфоксиде. Взаимодействие 2ʹ-гидроксифлаванона и его производного происходит по механизму интеркаляции. Изменение структуры молекулы 2ʹ-гидроксифлаванона путем модификации Шиффа приводит к усилению ДНК-связывающих свойств. Высокая аффинность связывания с ДНК 2ʹ-гидроксифлаванона и его производного в форме модификации Шиффа может найти применение при разработке противоопухолевых и антимикробных лекарств