Flavonoids are naturally occurring phenolic compounds named as 2-phenyl-1-benzopyran- 4-one and classified into several subclasses according to their basic chemical structures such as flavones, flavonols, flavanones, flavanonols, and flavanols. Among them, flavonols (3-hydroxyflavone), containing a 3-hydroxyl group in association with its 4-keto group and double bond between 2- and 3- carbon atoms, have the best electron conjugated skeleton in flavonoid family, providing several resonance structures and chelating ability, through which various pharmacological activities such as antiviral, antitumour, anti-inflammatory, anticholinesterase, cytotoxicity and particularly high antioxidant activity are demonstrated. They prevent generation of free radicals and are used as food preservatives. Their strong electron conjugation provides them with fluorescent property, which make them used as imaging agents for therapeutic purpose.

中文翻译：

---

3-羟基黄酮衍生物的最新进展：结构和性质。

黄酮类化合物是天然存在的酚类化合物，称为2-苯基-1-苯并吡喃-4-酮，并根据其基本化学结构分为几个亚类，例如黄酮，黄酮醇，黄烷酮，黄烷醇和黄烷醇。其中，黄酮醇（3-羟基黄酮）含有3-羟基及其4-酮基和2-和3-碳原子之间的双键，在类黄酮家族中具有最佳的电子共轭骨架，具有多个共振结构以及螯合能力，由此证明了各种药理活性，例如抗病毒，抗肿瘤，抗炎，抗胆碱酯酶，细胞毒性以及特别高的抗氧化活性。它们防止自由基的产生，并被用作食品防腐剂。