Natural quinazolinones: From a treasure house to promising anticancer leads.

Despite great advances in the development of modern anticancer drugs, it is still challenging to find safer and more effective ones due to a new spectrum of diseases and emerging drug resistance. Natural quinazolinones exist widely in natural plants, microorganisms and animals and possess a variety of biological activities. Over the past three to four decades, there has been a growing volume of literature concerning the effects of natural quinazolinones and their derivatives upon a variety of cancers. In this paper, 58 natural quinazolinones with anticancer activities were reviewed in term of their anticancer effects, cellular and molecular mechanisms, ability to overcome cancer drug resistance, and structure-activity relationship of anticancer quinazolinone representatives as well. This paper will offer new clues for discovering new and better lead compounds against malignant tumor and cancer drug resistance from natural quinazolinones.