Retrochalcone Explained

A retrochalcone is a chalcone-like compound in which the normally present hydroxy groups at the 2' and 6' positions are missing. The retrochalcone structure has a propenal bridge connected to two benzene rings at each end. The ring closest to the oxygen, is labelled with primed numbers, normally with a hydroxy group at the 4' position. This is the A ring. The ring closest to the double bond is numbered with simple digits starting from 1 at the bridge connection. This is the B ring. There is usually a hydroxy group at the 4 position. The retrochalcones are found naturally where they are derivatives of flavones.Retrochalcones can be classed as minor flavonoids.^[1]

One example derivative is echinatin.^[2] It has systematic name (E)-1-(4-hydroxyphenol)-3-(3-methoxy-4-hydroxyphenol)-2-propen-1-one, or derived name 4',4-dihydroxy-2-methoxychalcone and was found in Glycyrrhiza echinata.

List

• Licochalcone A (E)-3-[4-hydroxy-2-methoxy-5-(2-methylbut-3-en-2-yl)phenyl]-1-(4-hydroxyphenyl)prop-2-en-1-one^[3]
• Licochalcone B^[3]
• Licochalcone C^[3]
• Licochalcone D^[3]
• Licochalcone E (E)-3-[4-hydroxy-2-methoxy-5-[(2S)-3-methylbut-3-en-2-yl]phenyl]-1-(4-hydroxyphenyl)prop-2-en-1-one^[4]
• tepanone ((2E)-1-phenyl-3-(2´-hydroxy-3´,4´,6´-trimethoxyphenyl)prop-2-enone^[5]

Notes and References

1. Book: Marais. J.P.J.. Deavours. B.. Dixon. R.A. Ferreira. D.. Grotewold. Erich. The Science of Flavonoids. 2006. Springer. 0-387-28821-X. 4.
2. Book: Cazarolli. Luisa Helena. Kappel. Virginia Demarchi. Zanatta. Ana Paula. Suzuki. Daniela Ota Hisayasu. Yunes. Rosendo Augusto. Nunes. Ricardo José. Pizzolatti. Moacir Geraldo. Silva. Fátima Regina Mena Barreto. Studies in Natural Products Chemistry: Chapter 2. Natural and Synthetic Chalcones: Tools for the Study of Targets of Action—Insulin Secretagogue or Insulin Mimetic?. 2013. Elsevier Inc. Chapters. 9780128084823. en.
3. Book: Bidlack. Wayne R.. Omaye. Stanley T.. Meskin. Mark S.. Topham. Debra K. W.. Phytochemicals as Bioactive Agents. 2000. CRC Press. 9781566767880. 115. en.
4. Zhou. T. Deng. X. Qiu. J. Antimicrobial activity of licochalcone E against Staphylococcus aureus and its impact on the production of staphylococcal alpha-toxin.. Journal of Microbiology and Biotechnology. June 2012. 22. 6. 800–5. 10.4014/jmb.1112.12020. 22573157.
5. Hasliza. Yusof. Din. Laily B.. Yaacob. Wan A.. Ibrahim. Nazlina. Yamin. Bohari Mohd. Latiff. A.. The chemical constituents of Ellipeia cuneifolia and their antibacterial activity.. Sains Malaysiana. August 2015. 44. 8. 1125–1128. 10.17576/jsm-2015-4408-07. free.