title: Novel fungal metabolites as cell wall active antifungals: fermentation, isolation, physico-chemical properties, structure and biological activity.
abstract: Two novel antifungals SCH 643432 (1), and 2, were isolated from the fermentation broth of a fungus taxonomically classified as a Paecilomyces varioti. These compounds were separated from the fermentation broth filtrate by adsorption on a macroreticular resin XAD-16 (Amberlite). Purification and separation of the individual compounds were achieved by trituration of the extract with dichloromethane followed by preparative HPLC using reverse phase columns. Extensive FAB (Fast Atom Bombardment) and ESI (Electro Spray) mass spectrometric studies using fragmentation of various daughter ions, NMR experiments and degradative studies helped in elucidating the structure of compound 1. Compound 2 is an isomer of SCH 643432 (1). They were identified as straight chains peptides containing several amino acids such as alanine, aminoisobutyric acid, proline, leucine, glycine and arginine. The N-terminal is terminated in a previously identified beta-keto acid, 2-methyl 3-oxo tetradecanoic acid (MOTDA). Both compounds were active against Candida albicans, other Candidas, dermatophytes and Aspergillus (Geometric Mean MIC's 4.00, 2.59, 3.56, 11.31 and 4.49, 4.00, 5.66, 16.0 microg/ml, respectively for 1 and 2).
authors.affiliation: Schering Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA. vinod.hegde@spcorp.com
authors.forename: Vinod R
authors.initials: VR
authors.lastname: Hegde
authors.forename: Jack
authors.initials: J
authors.lastname: Silver
authors.forename: Mahesh
authors.initials: M
authors.lastname: Patel
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Gullo
authors.forename: Mohindar S
authors.initials: MS
authors.lastname: Puar
authors.forename: Pradip R
authors.initials: PR
authors.lastname: Das
authors.forename: David
authors.initials: D
authors.lastname: Loebenberg
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects; D005285:Fermentation; D003904:Mitosporic Fungi / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents