Chemistry and Biological Activities of Flavonoids: An Overview

Chemistry and Biological Activities of Flavonoids: An Overview


  • Flavonoids as complementary medicine for allergic diseases:

             Current evidence and future prospects.

  • Intake of flavonoids and risk of dementia
  • The Antioxidant Flavonoids, Orientin and Vicenin Enhance Repair of Radiation-Induced Damage


Antiviral Activity

Natural compounds are an important source for the discovery and the development of novel antiviral drugs because of their availability and expected low side effects. Naturally occurring flavonoids with antiviral activity have been recognized since the 1940s and many reports on the antiviral activity of

various flavonoids are available. Search of effective drug against human immunodeficiency virus (HIV) is the need of hour. Most of the work related with antiviral compounds revolves around inhibition of various enzymes associated with the life cycle of viruses. Structure function relationship between flavonoids and their enzyme inhibitory activity has been observed. Gerdin and Srensso demonstrated that flavan-3-o1 was more effective than flavones and flavonones in selective inhibition of HIV-1, HIV-2, and similar immunodeficiency virus infections. Baicalin, a flavonoid isolated from Scutellaria baicalensis (Lamieaceae), inhibits HIV-1 infection and replication. Baicalein and other flavonoids such as robustaflavone and hinokiflavone have also been shown to inhibit HIV-1 reverse transcriptase.


Another study revealed inhibition of HIV-1 entry into cells expressing CD4 and chemokine coreceptors and antagonism of HIV-1 reverse transcriptase by the flavone Oglycoside. Catechins are also known to inhibit DNA polymerases of HIV-1. Flavonoid such as demethylated gardenin A and robinetin are known to inhibit HIV-1 proteinase. It has also been reported that the flavonoids chrysin, acacetin, and apigenin prevent HIV-1 activation via a novel mechanism that probably involves inhibition of viral transcription.


Various combinations of flavones and flavonols have been shown to exhibit synergism. Kaempferol and luteolin show synergistic effect against herpes simplex virus (HSV). Synergism has also been reported between flavonoids and other antiviral agents. Quercetin is reported to potentiate the effects of 5- ethyl-2-dioxyuridine and acyclovir against HSV and pseudorabies infection. Studies have displayed that flavonols are more active than flavones against herpes simplex virus type 1 and the activity order was found to be galangin, kaempferol, and quercetin.


Zandi et al. studied the antidengue virus properties of quercetin, hesperetin, naringin, and daidzein at different stages of DENV-2 (dengue virus type-2) infection and replication cycle. Quercetin was found to be most effective against DENV-2 in Vero cells. Many flavonoids, namely, dihydroquercetin,

dihydrofisetin, leucocyanidin, pelargonidin chloride, and catechin, show activity against several types of   virus including HSV, respiratory syncytial virus, polio virus and Sindbis virus. Inhibition of viral polymerase and binding of viral nucleic acid or viral capsid proteins have been proposed as antiviral mechanisms of action.

  • Gerdin and E. Srensso, “Inhibitory effect of the flavonoid on increased

             microvascular permeability induced by various agents in rat skin,”

International Journal of Microcirculation, Clinical and Experimental, vol. 2, no.1, pp.39–46   1983.

  • P. T. Cushnie and A. J. Lamb, “Antimicrobial activity of flavonoids,”

              International Journal of Antimicrobial Agents, vol. 26, no. 5, pp. 343–356, 2005.

  • W. Critchfield, S. T. Butera, and T. M. Folks, “Inhibition of HIV activation in latently infected cells by flavonoid compounds,” AIDS Research and Human Retroviruses, vol. 12, no. 1, pp. 39–46, 1996.
  • Zandi, B. T. Teoh, S. S. Sam, P. F. Wong, M. R. Mustafa, and S. Abubakar, “Antiviral activity of four types of bioflavonoid against dengue virus type-2,” Virology Journal, vol. 8, article 560, 2011. View at:


  • Grienke, U. et al. Discovery of prenylated flavonoids with dual activity against influenza virus and Streptococcus pneumoniae. Sci. Rep. 6, 27156 (2016).
  • Pasetto, S., Pardi, V. & Mirata, R. M. Anti-HIV-1 activity of flavonoid myricetin onHIV-1 infection in a dual-chamber in vitro model. PloS One 9(12), e115323 (2014).
  • Sze, A. et al. Sophoraflavenone G Restricts Dengue and Zika Virus Infection via RNA Polymerase Interference. Viruses 9(10), E287 (2017).