17498-50-9Relevant articles and documents
Biocatalytic synthesis of valaciclovir using commercial enzymes
McClean, Kathleen,Preston, Christopher,Spence, David,Sutton, Peter W.,Whittall, John
, p. 215 - 218 (2011)
Proof-of-concept has been demonstrated for the biocatalytic transformation of aciclovir into valaciclovir, attaining high conversions from a solid-to-solid biotransformation in l-valine methyl ester using various formulations of Subtilisin Carlsberg activated for use in organic solvent.
An enantioselective synthesis of (S)-4-fluorohistidine
Hajduch, Jan,Cramer, John C.,Kirk, Kenneth L.
, p. 807 - 810 (2008)
We report a new synthesis of enantiomerically pure (S)-4-fluorohisitidine based on diastereoselective alkylation of MOM-protected 4-fluoro-5-bromomethyl imidazole using the Sch?llkopf bis-lactim amino acid synthesis. Improvements in procedures for preparation of key intermediates are also described. (S)-4-Fluorohisitidine prepared by this new method was identical in all respects to material prepared by previous procedures.
Cycloforskamide, a cytotoxic macrocyclic peptide from the sea slug Pleurobranchus forskalii
Tan, Karen Co,Wakimoto, Toshiyuki,Takada, Kentaro,Ohtsuki, Takashi,Uchiyama, Nahoko,Goda, Yukihiro,Abe, Ikuro
, p. 1388 - 1391 (2013/08/23)
A macrocylic dodecapeptide, cycloforskamide, was isolated from the sea slug Pleurobranchus forskalii, collected off Ishigaki Island, Japan. Its planar structure was deduced by extensive NMR analyses and was further confirmed by MS/MS fragmentation analyses. Finally, the absolute configuration was determined by total hydrolysis and chiral-phase gas chromatographic analysis. This novel dodecapeptide contains three d-amino acids and three thiazoline heterocycles and exhibits cytotoxicity against murine leukemia P388 cells, with an IC 50 of 5.8 μM.
Isolation and structural determination of the antifouling diketopiperazines from marine-derived Streptomyces praecox 291-11
Cho, Ji Young,Kang, Ji Young,Hong, Yong Ki,Baek, Hyo Hyun,Shin, Hyoun Woong,Kim, Myoung Sug
experimental part, p. 1116 - 1121 (2012/10/07)
Marine derived actinomycetes constituting 185 strains were screened for their antifouling activity against the marine seaweed, Ulva pertusa, and fouling diatom, Navicula annexa. Strain 291-11 isolated from the seaweed, Undaria pinnatifida, rhizosphere showed the highest antifouling activity and was identified as Streptomyces praecox based on a 16S rDNA sequence analysis. Strain 291-11 was therefore named S. praecox 291-11. The antifouling compounds from S. praecox 291-11 were isolated, and their structures were analyzed. The chemical constituents representing the antifouling activity were identified as (6S,3S)-6-benzyl-3-methyl-2,5-diketopiperazine (bmDKP) and (6S,3S)-6-isobutyl-3- methyl-2,5-diketopiperazine (imDKP) by interpreting the nuclear magnetic resonance and high-resolution mass spectroscopy data. Approximately 4.8mg of bmDKP and 3.1 mg of imDKP were isolated from 1.2 g of the S. praecox 291-11 crude extract. Eight different compositions of culture media were investigated for culture, the TBFeC medium being best for bmDKP and TCGC being the optimum for imDKP production. Two compounds respectively showed a 17.7 and 21 therapeutic ratio (LC50/EC50) to inhibit zoospores, and two compounds respectively showed a 263 and 120.2 therapeutic ratio to inhibit diatoms.