title: Semisynthetic modifications of hemiaminal function at ornithine unit of mulundocandin, towards chemical stability and antifungal activity.
abstract: Mulundocandin (1), is an echinocandin class of lipopeptide. It has wide spectrum of antifungal activity against Candida and Aspergillus species. Semisynthetic modification at Ornithine-5-hydroxyl (hemiaminal function) of 1 was carried out to improve solution stability and hence in vivo activity. Synthesis of ether (C-OR), thioether (C-SR) and C-N linkage at hemiaminal function have been described. All synthetic analogues were evaluated for their stability in aqueous solution and found to be more stable than mulundocandin. Antifungal activity of Orn-5 analogues was evaluated both in vitro against Candida albicans and Aspergillus fumigatus by agar well method and in vivo (oral and intraperitoneal) in C. albicans infected Swiss mice. Results of in vivo assays of analogues 2-9 by the oral route suggests that the introduction of either oxygen nucleophiles (-OR) or sulphur nucleophiles (-SR), at either Orn-5 or at both Orn-5 and HTyr-4 positions, results in retaining the activity of the parent compound with improved aqueous stability in most cases. Compound 9 has shown improved antifungal activity in comparison to mulundocandin by oral application in Swiss mice.
authors: Department of Medicinal Chemistry, Quest Institute of LifeSciences, Nicholas Piramal India Limited, Mulund (w) Mumbai 4000 80, India. bansilal@nicholaspiramal.co.in
authors: Bansi
authors: B
authors: Lal
authors: Vitthal Genbhau
authors: VG
authors: Gund
authors: Ashok Kumar
authors: AK
authors: Gangopadhyay
authors: S R
authors: SR
authors: Nadkarni
authors: Vidula
authors: V
authors: Dikshit
authors: D K
authors: DK
authors: Chatterjee
authors: R
authors: R
authors: Shirvaikar
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry* / Q000494:pharmacology*; D001232:Aspergillus fumigatus / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D004355:Drug Stability; D054714:Echinocandins; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D009952:Ornithine / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000494:pharmacology*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000935:Antifungal Agents; D054714:Echinocandins; D010456:Peptides, Cyclic; D009952:Ornithine; C052098:mulundocandin