The Systematic Identification of Flavonoids

About 1958 the late Professor R. E. ALSTON and Professor B. L. TURNER both of the Department ofBotany The University ofTexas at Austin initiated a general systematic investigation ofthe legurne genus Baptisia. They found that flavonoid patterns as revealed by two-dimensional paper chromatography were valid criteria for the recognition of the Baptisia species and for the documentation of their numerous natural hybrids. Later they showed that the flavonoid chemistry could be used for the analysis of gene flow among populations. At that time no attempt was made to even partially identify the flavonoids which were detected chromatographically. Neverthe1ess it soon became apparent that the full value of the chemical data for systematic purposes required knowledge of the structures of the flavonoids. In 1962 one of us (T.J.M.) in collaboration with Drs. ALSTON and TURNER beg an the chemical analysis of the more than 60 flavonoids which had been chromatographi­ cally detected in the 16 Baptisia species. In the intervening years a number of chemists and botanists inc1uding Drs. K. BAETCKE B. BREHM M. CRANMER D. HORNE J. KAGAN B. KROSCHEWSKY J. MCCLURE H. RÖSLER and J. WALLACE participated in the devel­ opment of techniques and procedures for the rapid identification of known flavonoids and in the structure determination of new flavonoids. In addition the flavonoid chem­ istry of many plants other than Baptisia was investigated.