Research Paper Summary: Synthesis of Polyrhacitides

Total Synthesis of Polyrhacitides A and B by use of an Iterative Strategy for the Stereoselective Synthesis of 1,3-Polyol Arrays

Helge Menz and Stefan F. Kirsch, Department Chemic and Catalysis Research Center, Technische Universitat Munchen, Germany, September 16, 2009. Original paper available here. What follows is our summary:

Polyrhacitide A and Polyrhacitide B moleculesIn late 2009 a German team achieved synthesis of Polyrhacitides A and B, two novel and promising bioactive compounds found in Chinese medicinal ants, genus polyrhachis.

Ants produce an astounding array of secondary metabolites including peptides, alkaloids and aromatic polyketides. In 2008, Jiang and Kuono isolated new compounds Polyrhacitides A and B from Chinese medicinal ant genus Polyrhachis, species lamellidens Smith. These aliphatic polyketides are comprised of a bicyclic lactone unit that is unusual in ants, although similar compounds are found in some plants.

This paper details the role in folk medicine of Chinese medicinal ants of genus Polyrhachis, and notes that this use has been substantiated by Chinese studies that extracts of polyrhachis ants exhibit significant anti-inflammatory and analgesic (pain-relieving) effects.

The authors point out that the pharmacological activity of these polyrhacitides has not been extensively researched in part due to unavailability of significant quantities of the natural ant-based substance, which they hope to remedy by making synthetic versions of the compounds available for further study.

They detail in the paper how they achieved the first total synthesis of Polyrhacitides A and B through a fully catalyst-controlled iterative approach based on asymmetric Overman esterification, resulting in stereochemical flexibility and providing substantial amounts of Polyrhacitides A and B to enable further research into their biological activity.

NOTE: This research as funded by German pharmaceutical company Boehringer Ingleheim, a clear signal that they are seeking to develop a proprietary pharmaceutical from Polyrhachis Ant Extract.