- Tasiamide F, a potent inhibitor of cathepsins D and E from a marine cyanobacterium
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In search of novel protease inhibitors with therapeutic potential, our efforts exploring the marine cyanobacterium Lyngbya sp. have led to the discovery of tasiamide F (1), which is an analogue of tasiamide B (2). The structure was elucidated using a combination of NMR spectroscopy and mass spectrometry. The key structural feature in 1 is the presence of the Phe-derived statine core, which contributes to its aspartic protease inhibitory activity. The antiproteolytic activity of 1 and 2 was evaluated in vitro against cathepsins D and E, and BACE1. Tasiamide F (1) displayed IC50values of 57?nM, 23?nM, and 0.69?μM, respectively, indicating greater selectivity for cathepsins over BACE1 compared with tasiamide B (2). Molecular docking experiments were carried out for compounds 1 and 2 against cathepsins D and E to rationalize their activity towards these proteases. The dysregulated activities of cathepsins D and E have been implicated in cancer and modulation of immune responses, respectively, and these proteases represent potential therapeutic targets.
- Al-Awadhi, Fatma H.,Ratnayake, Ranjala,Paul, Valerie J.,Luesch, Hendrik
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p. 3276 - 3282
(2016/07/21)
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- Synthesis of optically active α-methylamino acids and amides through biocatalytic kinetic resolution of amides
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Catalyzed by Rhodococcus sp. AJ270, a nitrile hydratase and amidase containing microbial whole-cell catalyst, under very mild conditions, a number of racemic α-methylamino amides were resolved into the corresponding optically active (S)-(+)-α-methylamino acids and (R)-(-)-α- methylamino amides. The steric requirement of the amidase against α-amino phenylacetamides bearing methyl group(s) at α-amino nitrogen and/or α-carbon was also studied. Coupled with the chemical hydrolysis of amide, the biotransformation process provided a direct synthesis of α-methylamino acids in both enantiomeric forms from readily available racemic amides.
- Wang, Mei-Xiang,Liu, Jun,Wang, De-Xian,Zheng, Qi-Yu
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p. 2409 - 2416
(2007/10/03)
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- Optical Resolution and Asymmetric Transformation of (RS)-N-Alkyl- and (RS)-N,N-Dialkyl-2-phenylglycines
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Optical resolution of (RS)-N-methyl-2-phenylglycine and (RS)-N-ethyl-2-phenylglycine was carried out by using (1S)-10-camphorsulfonic acid as resolving agents, and that of (RS)-N-ethyl-N-methyl-2-phenylglycine by (R)- and (S)-1-phenylethylamine.Racemization rates of optically active Mpg, Epg, Emp, N,N-dimethyl-2-phenylglycine , and six α-amino acids were measured by heating in carboxylic acids.The electron-donating amino acid side chain and N-substituted alkyl group decreased therate to inhibit the formation of intermediary carbanions, whereas the electron-withdrawing side chain increased it.Asymmetric transformation of (RS)-Mpg, (RS)-Epg, and (RS)-Dmp was carried out on the basis of the results of optical resolution and racemization to give the corresponding enantiomers of approximately 100percent optical purities in over 70percent yield based on the sterting racemates.
- Shiraiwa, Tadashi,Baba, Yoshihisa,Miyazaki, Hideya,Sakata, Shinji,Kawamura, Seiko,et al.
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p. 1430 - 1437
(2007/10/02)
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- NITROGEN ALKYLATION OF SCHIFF BASES AND AMIDINES AS A ROUTE TO N-ALKYL AMINO ACIDS
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Schiff base and amidine esters 3 are alkylated and then hydrolyzed to yield N-alkyl amino acids 4 in 41-75percent yield with hight to complete retention of optical activity.
- O'Donnell, Martin J.,Bruder, William A.,Daugherty, Byron W.,Liu, Deshan,Wojciechowski, Krzisztof
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p. 3651 - 3654
(2007/10/02)
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