October 2011 issue
Cover illustration: This compound, C23H22O5, also known as Caloxanthone C, was isolated from the stem bark of Calophyllum soulattri collected from the Sri Aman district in Sarawak, Malaysia. It consists of four six-membered rings and a 2-methylbut-3-en-2-yl side chain. The tricyclic xanthone ring system is almost planar [maximum deviation 0.093 (2) Å]. The pyranoid ring is in a distorted boat conformation, and the 2-methylbut-3-en-2-yl side chain is in a synperiplanar conformation. In the crystal, molecules are linked by a C-HO interaction, forming zigzag chains propagating in . See Ee, Mah, Kwong, Teh, Mohamed Tahir & Silong [Acta Cryst. (2011). E67, o2607-o2608].