In 1961, chemist Roberts noticed that polyphenolic xanthones had been isolated from lower fungi, lichens and from only three families which were Gentianaceae, Guttiferae and Anacardiaceae. In 1992, Mandal et al. found that many plants belonging to other 20 families also produced xanthones. They noticed that Gentianaceae and Guttiferae families were, in this order, the principal sources of xanthone derivatives.