Gambogic acid targets Hsp90

Hsp90 is a heat shock protein that is 90 kDa (for non biologists:  average amino acid molecular weight is approximately 110 Da – Da: daltons).  Hsp90 is a chaperone protein that is involved in a complex of other proteins that function to help fold, activate, and stabilize many other proteins that are involved in signal transduction.  Robert Matts and co-workers from Oklahoma State University have reported in the Journal of Natural Products on the complex between gambogic acid to the N-terminal domain of Hsp90.

 

JNP paper

Cupacinoxepin

Wolfgang Schuehly have reported in the Journal of Natural Products on the isolation of some antimalarial compounds including cupacinoxepin.

JNP paper

Longipedlactones K−P

Han-Dong Sun and co-workers at the Chinese Academy of Sciences have recently published in the Journal of Natural Products on the isolation of novel natural pentacyclic products that fall in the triterpene dilactone family of compounds isolated from the stems of Kadsura ananosma.  Longipedlactone J (compound 13) was found to have comparable in vitro cytotoxicity towards HL60 acute leukemia cell lines with cis-platin at 2.0 micromolar IC50 (cis platin had 1.7 micromolar).

JNP paper

Schisanbilactone A

Schisanbilactone A was isolated recently by Luping Qin and co-workers at the Second Military University in Shanghai.  Its interesting triterpenoid skeleton is a formidable challenge even for today’s synthetic chemist.

 

Helvetica Chimica Acta paper

Myrrhanol A

Alejandro Barrero at the University of Granada in Spain and co-workers have recently published in JOC on the synthesis of an anti-inflammatory agent,  myrrhanol A.  A key step in the synthesis was the reaction they used to make the 6,6-scaffold of the molecule, which involved a cascade titanium mediated bis-olefin epoxide opening cyclization.

JOC link