Chalcones dihydrochalcones

In three of the volumes of The Flavonoids, Advances in Research, published between 1975 and 1993, flavanones and dihydroflavonols were part of the chapter on Minor Flavonoids, expertly written by Professor Bruce Bohm. These Minor Flavonoid chapters also included chalcones, dihydrochalcones, and aurones. The term Minor Flavonoids was first used by Harborne in 1967 to encompass not only flavanones, chalcones, and aurones, but also isoflavonoids, biflavonyls, and leucoanthocyanidins, because so few compounds belonging to each of these flavonoid classes were known at that time. For example, only about 30 flavanone and dihydroflavonol aglycones, 19 chalcones, and 7 aurones were known in 1967. The number of known minor flavonoids increased considerably in the next two decades, so that when the checklist for The Flavonoids, Advances in Research Since 1980 was published in 1988, 429 known flavanones and dihydroflavonols (including glycosides) were listed, 268 chalcones and dihydrochalcones, and 29 aurones. In the last 15 years, the total number of known compounds in these flavonoid classes has more than doubled, so that the term minor flavonoids is no longer appropriate. Consequently, it has been decided that separate chapters should be devoted to the flavanones and dihydroflavonols (this chapter), and chalcones, dihydrochalcones, and aurones (Chapter 16). 

The chalcones, dihydrochalcones, and aurones are three distinctive classes of compound that comprise more than 900 of all the naturally occurring flavonoids reported in the literature to... 

FIGURE 16.1 Guide to the structures, ring labeling, and atom numbering of chalcones, dihydrochalcones, aurones, and auronols. The corresponding flavanone structure is shown for reference. 

Chalcones, dihydrochalcones, and aurones described in the literature from 1992 to 2003... 

APPENDIX B Checklist of Known Chalcones, Dihydrochalcones, and Aurones ... 

This checklist of chalcones, dihydrochalcones, and aurones contains compounds of these classes reported in the literature as natural products to the end of 2003. Compounds published before 1992 are cross-referenced to numbered entries in volumes 1 and 2 of the Handbook of Natural Flavonoidf using the abbreviations H1 and H2, respectively. Compounds published from 1992 to 2003 are cross-referenced to Table 16.1-Table 16.15 using numbers in bold type. The compounds are listed according to the system outlined in Section 16.1.1, with the exception that isoprenylated derivatives are included under the heading of aglycones. Bn, benzyl. 

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