Structures of a new type of yellow pigments, falconensones A and B, from Emericella falconensis

Abstract

Two new yellow pigments designated falconensones A 1 and B 2 have been isolated from the mycelium of Emericella falconensis and/or E. fruticulosa along with new azaphilone derivatives, falconensins A–H, and hopane-type triterpenes, zeorin, hopane-7β,22-diol, and hopane-6α,7β,22-triol. The structures of 1 and 2 have been determined by spectroscopic investigations and an X-ray analysis of the p-bromophenylhydrazone of 1 acetone solvate. Compounds 1 and 2 have a novel carbon skeleton: namely, they are cyclopent-2-enone derivatives connected to an extensively conjugated methyl ketone at C-3.

References

1. T. Itabashi, K. Nozawa, M. Miyaji, S. Udagawa, S. Nakajima and K. Kawai, Chem. Pharm. Bull., 1992, 40, 3142.
2. T. Itabashi, N. Ogasawara, K. Nozawa and K. Kawai, Chem. Pharm. Bull., 1996, 44, 2213.
3. T. Itabashi, K. Nozawa, S. Nakajima and K. Kawai, Chem. Pharm. Bull., 1993, 41, 2040.
4. Y. Horie, M. Miyaji, K. Nishimura and S. Udagawa, Trans. Mycol. Soc. Jpn., 1989, 30, 257.
5. Lists of atomic parameters, bond lengths and bond angles are available on request from the Cambridge Crystallographic Data Centre. Requests for such data should be accompanied by a full bibliographic reference for this work together with the reference number 207/130.
6. F. Hai-Fu, Structure Analysis Programs with Intelligent Control, Rigaku Corporation, Tokyo, Japan ( 1991).
7. P. T. Beurkens, G. Admiraal, G. Beurkens, W. P. Bosman, S. Garcia-Granda, R. O. Gould, J. M. M. Smits and C. Smykalla, The DIRDIF program system, Technical Report of the Crystallography Laboratory, University of Nijmegan, The Netherlands ( 1992).