- Design and synthesis of novel symmetric fluorene-2,7-diamine derivatives as potent hepatitis C virus inhibitors
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Hepatitis C virus (HCV) is an international challenge. Since the discovery of NS5A direct-acting antivirals, researchers turned their attention to pursue novel NS5A inhibitors with optimized design and structure. Herein we explore highly potent hepatitis C virus (HCV) NS5A inhibitors; the novel analogs share a common symmetrical prolinamide 2,7-diaminofluorene scaffold. Modification of the 2,7-diaminofluorene backbone included the use of (S)-prolinamide or its isostere (S,R)-piperidine-3-caboxamide, both bearing different amino acid residues with terminal carbamate groups. Compound 26 exhibited potent inhibitory activity against HCV genotype (GT) 1b (effective concentration (EC50) = 36 pM and a selectivity index of >2.78 × 106). Compound 26 showed high selectivity on GT 1b versus GT 4a. Interestingly, it showed a significant antiviral effect against GT 3a (EC50 = 1.2 nM). The structure-activity relationship (SAR) analysis revealed that picomolar inhibitory activity was attained with the use of S-prolinamide capped with R- isoleucine or R-phenylglycine residues bearing a terminal alkyl carbamate group.
- Mousa, Mai H. A.,Ahmed, Nermin S.,Schwedtmann, Kai,Frakolaki, Efseveia,Vassilaki, Niki,Zoidis, Grigoris,Weigand, Jan J.,Abadi, Ashraf H.
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- Synthesis of enantiopure free and N-benzyloxycarbonyl-protected 3-substituted homotaurines from naturally occurring amino acids
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Enantiopure N-benzyloxycarbonyl-protected and free 3-substituted homotaurines were synthesized from naturally occurring amino acids via N-benzyloxycarbonyl protection, Arndt-Eistert homologation, reduction, esterification with thioacetic acid, and oxidation with performic acid. The current method is a convenient, practical, and salt-free method for the synthesis of enantiopure 3-substituted homotaurine with moderate to good yields.
- Zheng, Yongpeng,Xu, Jiaxi
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p. 5197 - 5206
(2014/12/10)
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- Design, synthesis, and biological evaluation of novel dipeptide-type SARS-CoV 3CL protease inhibitors: Structure-activity relationship study
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This work describes the design, synthesis, and evaluation of low-molecular weight peptidic SARS-CoV 3CL protease inhibitors. The inhibitors were designed based on the potent tripeptidic Z-Val-Leu-Ala(-pyrrolidone-3-yl)-2-benzothiazole (8; Ki = 4.1 nM), in which the P3 valine unit was substituted with a variety of distinct moieties. The resulting series of dipeptide-type inhibitors displayed moderate to good inhibitory activities against 3CLpro. In particular, compounds 26m and 26n exhibited good inhibitory activities with Ki values of 0.39 and 0.33 μM, respectively. These low-molecular weight compounds are attractive leads for the further development of potent peptidomimetic inhibitors with pharmaceutical profiles. Docking studies were performed to model the binding interaction of the compound 26m with the SARS-CoV 3CL protease. The preliminary SAR study of the peptidomimetic compounds with potent inhibitory activities revealed several structural features that boosted the inhibitory activity: (i) a benzothiazole warhead at the S1′ position, (ii) a γ-lactam unit at the S1-position, (iii) an appropriately hydrophobic leucine moiety at the S2-position, and (iv) a hydrogen bond between the N-arylglycine unit and a backbone hydrogen bond donor at the S3-position.
- Thanigaimalai, Pillaiyar,Konno, Sho,Yamamoto, Takehito,Koiwai, Yuji,Taguchi, Akihiro,Takayama, Kentaro,Yakushiji, Fumika,Akaji, Kenichi,Kiso, Yoshiaki,Kawasaki, Yuko,Chen, Shen-En,Naser-Tavakolian, Aurash,Sch?n, Arne,Freire, Ernesto,Hayashi, Yoshio
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p. 436 - 447
(2013/10/01)
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- Assay and inhibition of diacylglycerol lipase activity
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A series of N-formyl-α-amino acid esters of β-lactone derivatives structurally related to tetrahydrolipstatin (THL) and O-3841 were synthesized that inhibit human and murine diacylglycerol lipase (DAGL) activities. New ether lipid reporter compounds were developed for an in vitro assay to efficiently screen inhibitors of 1,2-diacyl-sn-glycerol hydrolysis and related lipase activities using fluorescence resonance energy transfer (FRET). A standardized thin layer chromatography (TLC) radioassay of diacylglycerol lipase activity utilizing the labeled endogenous substrate [1″- 14C]1-stearoyl-2-arachidonoyl-sn-glycerol with phosphorimaging detection was used to quantify inhibition by following formation of the initial product [1″-14C]2-arachidonoylglycerol and further hydrolysis under the assay conditions to [1-14C]arachidonic acid.
- Johnston, Meghan,Bhatt, Shachi R.,Sikka, Surina,Mercier, Richard W.,West, Jay M.,Makriyannis, Alexandros,Gatley, S. John,Duclos Jr., Richard I.
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scheme or table
p. 4585 - 4592
(2012/08/08)
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- Design and synthesis of potent Quillaja saponin vaccine adjuvants
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The success of antitumor and antiviral vaccines often requires the use of an adjuvant, a substance that significantly enhances the immune response to a coadministered antigen. Only a handful of adjuvants have both sufficient potency and acceptable toxicity for clinical investigation. One promising adjuvant is QS-21, a saponin natural product that is the immunopotentiator of choice in many cancer and infectious disease vaccine clinical trials. However, the therapeutic promise of QS-21 adjuvant is curtailed by several factors, including its scarcity, difficulty in purification to homogeneity, dose-limiting toxicity, and chemical instability. Here, we report the design, synthesis, and evaluation of chemically stable synthetic saponins. These novel, amide-modified, non-natural substances exhibit immunopotentiating effects in vivo that rival or exceed that of QS-21 in evaluations with the GD3-KLH melanoma conjugate vaccine. The highly convergent synthetic preparation of these novel saponins establishes new avenues for discovering improved molecular adjuvants for specifically tailored vaccine therapies.
- Adams, Michelle M.,Damani, Payal,Perl, Nicholas R.,Won, Annie,Hong, Feng,Livingston, Philip O.,Ragupathi, Govind,Gin, David Y.
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supporting information; experimental part
p. 1939 - 1945
(2010/05/11)
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- Determination of the complete absolute configuration of petriellin A
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We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey's derivatives and Marfey's derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids. CSIRO 2006.
- Aurelio, Luigi,Brownlee, Robert T. C.,Dang, Jason,Hughes, Andrew B.,Polya, Gideon M.
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p. 407 - 414
(2008/02/04)
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- Aza-Wittig rearrangement of N,N-dipropargylic α-amino alkyllithiums: Periselectivity and steric course
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The aza-Wittig rearrangement of enantio-defined N,N-dipropargylic α-amino alkyllithiums, generated by tin-lithium exchange, are shown to afford [1,2]- and/or [2,3]-rearrangement products. Both aza-Wittig rearrangements proceed predominantly with inversion of configuration at the Li-bearing carbon terminus.
- Tomoyasu, Takahiro,Tomooka, Katsuhiko
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p. 1925 - 1928
(2007/10/03)
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- Acyclic stereoselective boron alkylation reactions for the asymmetric synthesis of β-substituted α-amino acid derivatives
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Optically active syn- or anti-β-substituted-α-amino acid derivatives are prepared in 94 to ≥99% ee and 66-98% ds by reaction of the Schiff base acetate of glycine tert-butyl ester with chiral, nonracemic B-alkyl-9-BBN derivatives in the presence of the Cinchona alkaloid, cinchonidine (CdOH) or cinchonine (CnOH), base, and lithium chloride. Copyright
- O'Donnell, Martin J.,Cooper, Jeremy T.,Mader, Mary M.
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p. 2370 - 2371
(2007/10/03)
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- Total syntheses and biological investigations of tamandarins A and B and tamandarin A analog
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Tamandarins A (1) and B (2), two natural products similar in structure to didemnin B (3), were recently isolated from a Brazilian marine ascidian of the family Didemnidae. The cytotoxicity of 1 was reported to be somewhat more potent in vitro than that of 3 against various human cancer cell lines. The present account describes the first total syntheses of 1 and 2, and the syntheses of tamandarin A side chain analogues. The cytotoxicity data for these compounds show that the side chain modifications exhibit a parallel effect for both didemnins and tamandarins. This observation supports tamandarins' role as didemnins' mimic.
- Liang,Richard,Portonovo,Joullie
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p. 4469 - 4474
(2007/10/03)
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- 4-SUBSTITUTED -3-[1 OR 2 AMINO ACID RESIDUE]-AZETIDIN-2-ONE DERIVATIVES USEFUL AS CYSTEINE PROTEINASE INHIBITOR
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Disclosed herein are azetidin-2-one compounds which exhibit excellent cysteine proteinase inhibitory activity. The compounds are 4-substituted-3-{1 or 2 amino acid residue}-azetidin-2-ones of forumula I STR1 wherein AAR is a 1 or 2 acid residue, and R 1 and R 2 are as defined herein. The compounds can be used in the treatment of various diseases such as muscular dystrophy, bone resorption disorders, myocardial infarction and cancer metastasis.
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- The first total synthesis of (-)-tamandarin A.
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[formula: see text] Tamandarin A (1), a newly isolated natural product similar in structure to didemnin B (2), was shown to be somewhat more active in vitro than 2 against pancreatic carcinoma with an ED50 value 1.5 to 2 ng/mL. We report here the first total synthesis of 1. The key steps include a practical stereoselective synthesis of the Hiv-isostatine unit, high-yielding linear precursor formation, a successful macrocyclization, and coupling of the macrocycle with the side chain to afford tamandarin A (1).
- Liang,Portonovo,Vera,Xiao,Joullie
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p. 1319 - 1322
(2008/02/09)
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- Ruthenium-catalysed cross metathesis binding of functionalized olefins to polystyrene resin via a novel allylsilyl linker suitable for electrophilic cleavage
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1% Divinylbenzene-crosslinked allyldimethylsilyl polystyrene 1 undergoes highly efficient ruthenium-catalysed cross-metathesis with functionalized terminal olefins and allows electrophilic cleavage of the resulting functionalized allylsilane.
- Schuster, Matthias,Lucas, Norbert,Blechert
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p. 823 - 824
(2007/10/03)
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- Synthesis of D-Alloisoleucine from L-Isoleucine and from (S)-2-Methylbutan-1-ol. Synthesis of Isostatine
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Three different synthetic routes to the uncommon α-amino acid D-alloisoleucine were studied.The first was based on the stereospecific inversion of configuration of the C-2 stereogenic carbon of L-isoleucine.The second involved acetylation of L-isoleucine with epimerization at the C-2 carbon, giving a mixture of L-isoleucine and D-alloisoleucine, which was resolved enzymically with hog kidney acylase.In a new approach, an epimeric mixture of L-isoleucine and D-alloisoleucine was synthesized from (S)-2-methylbutan-1-ol and was again resolved enzymically.The D-alloisoleucine produced in these syntheses was subsequently transformed into the γ-amino acid isostatine.
- Lloyd-Williams, Paul,Monerris, Patricia,Gonzalez, Isabel,Jou, Gemma,Giralt, Ernest
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p. 1969 - 1974
(2007/10/02)
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- Structure and synthesis of arthonin, a lichen metabolite from Arthonia endlicheri
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Arthonin, a metabolite of the lichen Arthonia endlicheri has been structurally elucidated as (-)-N-benzoyl-L-valinyl N'-benzoyl-L-isoleucinate. The syntheses of arthonin and iso-arthonin [(-)-N-benzoyl-L-isoleucyl-O-benzoyl-L-valinol] are described.
- Huneck,Porzel,Schmidt
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p. 303 - 311
(2007/10/02)
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- 3,5-substituted 4,5-dihydroisoxazoles as transglutaminase inhibitors
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The present invention is directed to certain 3,5 substituted, 4,5-dihydroisoxazoles, and methods for their use. These compounds are transgulatminase inhibitors, and are particularly effective in the inhibition of epidermal transglutaminase and the treatment of acne.
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- Composition containing a penem or carbapenem antibiotic and the use of the same
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Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially.
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- Composition containing a penem or carbapenem antibiotic
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Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially. The composition may be prepared by simple mixing.
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- Stereoselective Micellar Catalysis. Part 3. Co-operative Effects of N-Decanoyl-L-histidine for the Hydrolysis of Enantiomeric Substrates
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The catalytic activities of N-decanoyl-L-histidine (Ia) and its methyl ester (Ib) toward the hydrolyses of enantiomeric substrates (II) have been investigated in the presence of cetyltrimethylammonium bromide micelles.The comparison of catalytic effects (both the rate constants and stereoselectivities) of (Ia) and (Ib) strongly suggests that carboxylate ion of (Ia) intramolecularly enhances the reactivity of the imidazole group.The presence of co-operative effects is also supported by the pH-rate profile and by the thermodynamic parameters of the reaction.
- Ihara, Yasuji,Hosako, Reiko,Nango, Mamoru,Kuroki, Nobuhiko
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