Rikito Suzuki

Isolation, Structure Elucidation, and Synthesis of Psds Liquid/liquid extraction of the P. cascadensis fermentation culture filtrate, followed by RP 18 flash chromatography, and repetitive rounds of HPLC using RP 18 and RP CN conditions provided Psds A–D ( 1 – 4 ). To further characterize the planar structures inferred from MS/MS fragmentations, comprehensive 1D and 2D NMR data were acquired in CDCl 3 at 800 MHz for 1 – 4 .

Cyclic peptide natural products, especially those possessing N-methylations are considered privileged structures for pharmaceutical drug discovery owing to a high likelihood of being able to permeate cell membranes and to bind to endogenous targets. (1,2) Cyclosporin, a life-saving immunosuppressant, is the best known example of a highly N-methylated fungal cyclic peptide.