37755-48-9

Upstream product

• 20312-37-2 (R)-2-hydroxy-4-methylpentanoic acid 
• 100-39-0 benzyl bromide 
• 96136-13-9 4-methyl-2-oxo-pentanoic phenylmethyl ester acid 
• 100-51-6 benzyl alcohol 
• 328-38-1 (R)-leucine 
• 13748-90-8 (S)-2-hydroxyl-3,3-dimethylbutyric acid 
• 54641-21-3 (S)-(-)-sodium 2-hydroxy-4-methylpentanoate 
• 61-90-5 L-leucine 
• 117-34-0 2,2-diphenylacetic acid 
• 321329-81-1 benzyl 2-hydroxy-4-methylpentanoate 
• 1760-46-9 diphenylacetic anhydride 

Downstream Products

• 55739-20-3 benzyl (2R)-2-(3-tert-butoxycarbonylaminopropionyloxy)-4-methylpentanoate 
• 36157-88-7 4-Nitro-benzoic acid (R)-1-benzyloxycarbonyl-3-methyl-butyl ester 
• 130317-28-1 benzyl 2R-trifluoromethanesulfonyloxy-4-methylvalerate 
• 149990-44-3 N-<(R)-1-<(1,1-dimethylethoxy)carbonyl>-3-<<(1,1-dimethylethyl)dimethylsilyl>oxy>propyl>-L-leucine, phenylmethyl ester 
• 197172-41-1 C₂₁H₃₆N₂O₄Si 
• 197172-44-4 (S)-2-(N'-tert-Butoxycarbonyl-N-{(R)-2-[(2S,3S)-2-((S)-sec-butyl)-1-(tert-butyl-dimethyl-silanyl)-4-oxo-azetidin-3-yloxy]-4-methyl-pentanoyl}-hydrazino)-4-methyl-pentanoic acid benzyl ester 
• 197172-45-5 (S)-2-(N'-tert-Butoxycarbonyl-N-{(S)-2-[(2S,3S)-2-((S)-sec-butyl)-1-(tert-butyl-dimethyl-silanyl)-4-oxo-azetidin-3-yloxy]-4-methyl-pentanoyl}-hydrazino)-4-methyl-pentanoic acid benzyl ester 
• 149967-27-1 N-<(R)-1-<(1,1-dimethylethoxy)carbonyl>-3-hydroxypropyl>-L-leucine, phenylmethyl ester 
• 149967-28-2 N-<(R)-1-<(1,1-dimethylethoxy)carbonyl>-3-(1,3-dihydro-1,3-dioxo-2H-benzisoindol-2-yl)propyl>-L-leucine, phenylethyl ester 
• 154296-23-8 N-<1-(R)-<(1,1-dimethylethoxy)carbonyl>-3-(1,3-dihydro-1,3-dioxo-2H-benzisoindol-2-yl)propyl>-N'-(phenylmethyl)-L-leucinamide 
• 154296-39-6 4-(1,3-dihydro-1,3-dioxo-2H-benzisoindol-2-yl)-2-(R)-<<3-methyl-1-(S)-<<(benzylmethyl)amino>carbonyl>butyl>amino>butanoic acid, 1,1-dimethylethyl ester 
• 154296-22-7 N-<1-(R)-<(1,1-dimethylethoxy)carbonyl>-3-(1,3-dihydro-1,3-dioxo-2H-benzisoindol-2-yl)propyl>-N'-(phenylethyl)-L-leucinamide 

Relevant academic research and scientific papers

Potent Anti-SARS-CoV-2 Activity by the Natural Product Gallinamide A and Analogues via Inhibition of Cathepsin L

Cathepsin L is a key host cysteine protease utilized by coronaviruses for cell entry and is a promising drug target for novel antivirals against SARS-CoV-2. The marine natural product gallinamide A and several synthetic analogues were identified as potent inhibitors of cathepsin L with IC50 values in the picomolar range. Lead molecules possessed selectivity over other cathepsins and alternative host proteases involved in viral entry. Gallinamide A directly interacted with cathepsin L in cells and, together with two lead analogues, potently inhibited SARS-CoV-2 infection in vitro, with EC50 values in the nanomolar range. Reduced antiviral activity was observed in cells overexpressing transmembrane protease, serine 2 (TMPRSS2); however, a synergistic improvement in antiviral activity was achieved when combined with a TMPRSS2 inhibitor. These data highlight the potential of cathepsin L as a COVID-19 drug target as well as the likely need to inhibit multiple routes of viral entry to achieve efficacy.

A versatile chemoenzymatic synthesis for the discovery of potent cryptophycin analogs

The cryptophycins are a family of macrocyclic depsipeptide natural products that display exceptionally potent antiproliferative activity against drug-resistant cancers. Unique challenges facing the synthesis and derivatization of this complex group of molecules motivated us to investigate a chemoenzymatic synthesis designed to access new analogs for biological evaluation. The cryptophycin thioesterase (CrpTE) and the cryptophycin epoxidase (CrpE) are a versatile set of enzymes that catalyze macrocyclization and epoxidation of over 20 natural cryptophycin metabolites. Thus, we envisioned a drug development strategy involving their use as standalone biocatalysts for production of unnatural derivatives. Herein, we developed a scalable synthesis of 12 new unit A-B-C-D linear chain elongation intermediates containing heterocyclic aromatic groups as alternatives to the native unit A benzyl group. N-Acetyl cysteamine activated forms of each intermediate were assessed for conversion to macrocyclic products using wild type CrpTE, which demonstrated the exceptional flexibility of this enzyme. Semipreparative scale reactions were conducted for isolation and structural characterization of new cryptophycins. Each was then evaluated as a substrate for CrpE P450 and its ability to generate the epoxidized products from these substrates that possess altered electronics at the unit A styrenyl double bond position. Finally, biological evaluation of the new cryptophycins revealed a des-β-epoxy analog with low picomolar potency, previously limited to cryptophycins bearing epoxide functionality.

Design of Gallinamide A Analogs as Potent Inhibitors of the Cysteine Proteases Human Cathepsin L and Trypanosoma cruzi Cruzain

Gallinamide A, originally isolated with a modest antimalarial activity, was subsequently reisolated and characterized as a potent, selective, and irreversible inhibitor of the human cysteine protease cathepsin L. Molecular docking identified potential modifications to improve binding, which were synthesized as a suite of analogs. Resultingly, this current study produced the most potent gallinamide analog yet tested against cathepsin L (10, Ki = 0.0937 ± 0.01 nM and kinact/Ki = 8 730 000). From a protein structure and substrate preference perspective, cruzain, an essential Trypanosoma cruzi cysteine protease, is highly homologous. Our investigations revealed that gallinamide and its analogs potently inhibit cruzain and are exquisitely toxic toward T. cruzi in the intracellular amastigote stage. The most active compound, 5, had an IC50 = 5.1 ± 1.4 nM, but was relatively inactive to both the epimastigote (insect stage) and the host cell, and thus represents a new candidate for the treatment of Chagas disease.

Learning from Peptides to Access Functional Precision Polymer Sequences

Functional precision polymers based on monodisperse oligo(N-substituted acrylamide)s and oligo(2-substituted-α-hydroxy acid)s have been synthesized. The discrete sequences originate from a direct translation of side-chain functionality sequences of a peptide with well-studied properties. The peptide was previously selected to solubilize the photosensitizer meta-tetra(hydroxyphenyl)chlorin. The resulting peptidomimetic formulation additives preserve the drug solubilization and release characteristics of the parent peptide. In some cases, superior properties are obtained, reaching up to 40 % higher payloads and 27-times faster initial drug release.

Design and synthesis of a new class of cryptophycins based tubulin inhibitors

Tubulin binding compounds represent one of the most attractive targets for anticancer drug development. They broadly fall into two categories viz., tubulin polymerization inhibitors, which block microtubule growth and destabilize microtubules like vinca alkaloids and cryptophycins, and the others, which polymerize microtubules into hyperstable forms represented by family of taxanes. In this context, we aimed at design and synthesis of cryptophycins based macrocyclic depsipeptides, which are synthetically more accessible, however have the basic information to target tubulins and establish structure activity relationship (SAR). Thus, a new class of cryptophycins based marocyclic depsipeptides with a truncated epoxide chain were synthesized as potential tubulin inhibitors. The resultant lead analogues 15a and 16a exhibited good anti-cancer activity, induced apoptosis, caused block/delay in cell cycle as well as significantly reduced the expression of α- and β-tubulins. Molecular modelling studies show that 15a and 16a bind in the same domain as that of cryptophycins.

Preparation and evaluation at the delta opioid receptor of a series of linear Leu-enkephalin analogues obtained by systematic replacement of the amides

Leu-enkephalin analogues, in which the amide bonds were sequentially and systematically replaced either by ester or N-methyl amide bonds, were prepared using classical organic chemistry as well as solid phase peptide synthesis (SPPS). The peptidomimetics were characterized using competition binding, ERK1/2 phosphorylation, receptor internalization, and contractility assays to evaluate their pharmacological profile over the delta opioid receptor (DOPr). The lipophilicity (LogD7.4) and plasma stability of the active analogues were also measured. Our results revealed that the last amide bond can be successfully replaced by either an ester or an N-methyl amide bond without significantly decreasing the biological activity of the corresponding analogues when compared to Leu-enkephalin. The peptidomimetics with an N-methyl amide function between residues Phe and Leu were found to be more lipophilic and more stable than Leu-enkephalin. Findings from the present study further revealed that the hydrogen-bond donor properties of the fourth amide of Leu-enkephalin are not important for its biological activity on DOPr. Our results show that the systematic replacement of amide bonds by isosteric functions represents an efficient way to design and synthesize novel peptide analogues with enhanced stability. Our findings further suggest that such a strategy can also be useful to study the biological roles of amide bonds.

Continuous multiple liquid-liquid separation: Diazotization of amino acids in flow

A second-generation laboratory-scale, modular liquid-liquid separation device based on computer-controlled high-pressure pumps and a high-resolution digital camera has been invented. The diazotization of amino acids to produce valuable chiral hydroxyacids is demonstrated in flow for the first time. The use of a triple-separator system in conjuction with the developed diazotization process allows the safe and efficient production and automated isolation of multigram quantities of valuable chiral hydroxyacids.

Synthesis, characterization and activity of new phosphonate dipeptides as potential inhibitors of VanX

VanX, a Zn(II)-dependent D-ala-D-ala dipeptidase, is essential for vancomycin resistance in Enterococcus faecium. The enzymatic activity of VanX was previously found to be inhibited competitively by 2-{[(1-aminoethyl) (hydroxy) phosphoryl]oxy} propanoic acid (1B). Here we report the synthesis and characterization of seven phosphonate dipeptide analogs of D-ala-D-ala with various substituent, the activity evaluation indicated that six of these phosphonate analogs inhibit VanX with IC50 of 0.48-8.21 mM. These data revealed a structure-activity relationship which is that the large substituent group on β-carbon resulted in low binding affinity of the phonphonate analog to VanX. This information will be helpful to guide the design and synthesis of the tightly-binding inhibitors for VanX.

A convenient method for the kinetic resolution of racemic 2-hydroxyalkanoates using diphenylacetic anhydride (DPHAA) and a chiral acyl-transfer catalyst

Diphenylacetic anhydride (DPHAA) was found to be a useful reagent for the kinetic resolution of racemic 2-hydroxyalkanoates in the presence of a catalytic amount of (R)-benzotetramisole ((R)-BTM). The combined use of DPHAA and (R)-BTM effectively produced a variety of the optically active 2-hydroxyalkanoates and the corresponding 2-acyloxyalkanoates from racemic 2-hydroxyalkanoates (s-values = 42-177). A fairly broad substrate scope was demonstrated by this novel chiral induction system. We also revealed that the use of only 0.3 equiv of DPHAA is enough to provide the optically active 2-acyloxyalkanoates in good yields and with excellent ee's by the added use of 0.3 equiv of pivalic anhydride for the kinetic resolution of the racemic 2-hydroxyalkanoates. Copyright

METHOD FOR PRODUCING OPTICALLY ACTIVE 2-HYDROXY ESTER AND NOVEL INTERMEDIATE COMPOUND

Disclosed is a method for producing an optically active 2-hydroxy ester, comprising selectively esterifying one enantiomer of a racemic 2-hydroxy ester in a solvent containing a catalyst such as tetramisole or benzotetramisole, and a carboxylic acid anhydride, or a carboxylic acid anhydride and a carboxylic acid. In particular, in the case where the solvent contains a carboxylic acid anhydride, but does not contain a carboxylic acid, as the carboxylic acid anhydride, a carboxylic acid anhydride containing a tertiary or quaternary carbon atom in the a-position is used. On the other hand, in the case where the solvent contains a carboxylic acid anhydride and a carboxylic acid, as the carboxylic acid, a carboxylic acid containing a tertiary or quaternary carbon atom in the a-position is used.