Optically pure 3-aryloxy-1,2-propanediols are important intermediates in the synthesis of various pharmaceutical compounds. This study reports the kinetics and mechanism of lipase catalyzed regioselective monoacetylation of 3-aryloxy-1,2-propandiols. Regioselective monoacetylation of 3-(2-methyl...

The stereochemistry of the Candida antarctica lipase B (CALB) catalyzed resolution of diacetate 1 or diol 4 was analyzed. The primary and secondary acetate hydrolyses were studied separately using monoacetates 2 and 3. The enantioselectivity of CALB was found to be lower towards primary rather t...

We describe a new approach for predicting the enantioselectivity of enzymes towards racemic compounds. It is based on comparative binding energy (COMBINE) analysis.The approach is used to rationalise the enantioselectivity of Burkholderia cepacia lipase (BCL) towards thirteen racemic 3-(aryloxy)...

The toxicity of 1,2-propanediol is reviewed, and a table of the LD50 values for the rat, rabbit, mouse, guinea pig, and dog is presented. Metabolic and chronic studies demonstrate that 1,2-propanediol can be used as a substitute for carbohydrate in the diet of rats and young chicks. The glycol i...

An amphiphilic microenvironment is a key element to the lipase which catalyzes substrates at the aqueous and hydrophobic interface. An amphiphilic comb copolymer, poly(sodium acrylate)-g-methoxy poly(ethylene oxide), was introduced for the post-functionalization of mesoporous TiO2. The lipase fr...

The stereospecific synthesis of glycoprotein processing enzyme inhibitor (+) mannostatin A 1 was achieved in ten steps from D-ribonolactone 9 (∼ 39% overall yield). The strategy featured methanesulfenyl triflate mediated intramolecular cyclization of allylic N-sufenylimidate 12.

Publisher SummaryThe chapter discusses the synthesis of mannostatins, cyclophellitol and their analogues, focusing on the progress in the stereoselective, enantioselective and chiral synthesis. The structure of mannostatin A was first clarified to be (1,2,3,4/5)-4-amino-5-(methylthio)-l,2,3-cycl...

Mannostatins A and B, along with the respective enantiomer and diastereoisomer having the (S)-sulfinyl function, were synthesized from myo-inositol. Inhibitory activity of the synthetic compounds against jack bean α-mannosidase was measured, revealing that the 4-aminocyclopentane-1,2,3-triol st...

A synthesis of kifunensine (1) has been achieved by a route involving, as a key step, a double cyclization of aldehyde 3 with ammonia.

In the present study, a systematic vibrational spectroscopic investigation for the experimental IR and Raman spectra of 2,3,4-trifluorobenzonitrile (TFB), aided by electronic structure calculations has been carried out. The electronic structure calculations – ab initio (RHF) and hybrid density ...

Directed nucleophilic substitution of two fluorine atoms in title compounds 1, 2 by diphenylphosphine groups was used to prepare new chelating electron-deficient diphosphine ligands 3 and 4 ; the structure of 4 was confirmed by XRD analysis

A metal-free decarboxylative coupling reaction, which produced important and useful dipropargylic amines, was developed under mild conditions. This novel methodology showed a broad range of functional-group compatibility for primary amines and propiolic acids, and gave the corresponding products...

The utility of sulfamic acid for the preparation of diverse steroid sulfates has been investigated. Sulfates of the following steroids were prepared and characterized: testosterone, choleseterol, pregnenolone, dehydroisoandrosterone, estrone, 2-methyoxyestrone, ethynylestradiol and ethynylestera...

Chemoselective differentiation of the primary hydroxy groups in 14,17α-bis(hydroxymethyl)-3-methoxyestra-1,3,5(10)-trien-17β-ol (2) has been investigated in a series of reactions which lead inter alia to novel 14,17-hetero-bridged steroid hormone analogues. Thus routes are described to 3-metho...

The introduction of a hydrazine functionality into 2-(2-cyanovinyl)-3-oxo-cyclohex-1-ene enolates results in their spontaneous cyclizations with participation of the hydrazine moiety. Depending on the reaction conditions used, the hydrazine-derived enolates are transformed into derivatives of 1-...

We have previously synthesized a series of 1,8-naphthyridine-3-carboxamide derivatives to identify potential anti-cancer/anti-inflammatory compounds. Three derivatives, 7-chloro-N-(3-(cyclopentylamino)-3-oxo-1-phenylpropyl)-6-fluoro-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carbox...

In this work, we report a series of new 4-oxo-1,4-dihydro-quinoline-3-carboxamide derivatives as β-secretase (BACE-1) inhibitors. Supported by docking study, a small library of derivatives were designed, synthesized and biologically evaluated in vitro. The studies revealed that the most potent ...

The effect of inactivation of DppA, a dipeptide transport protein identified as a periplasmic molecular chaperone-like protein, on the formation of active dimethyl sulfoxide reductase (DMSOR) was examined in Rhodobacter sphaeroides f. sp. denitrificans. All of the dppA-disrupted mutants produced...

Collagen, an important fibrous protein and its stability is closely related to organizational order. In this work, organization of collagen in the presence of diphenyl phosphoryl azide (DPPA) was studied using circular dichroic spectroscopy, stress–strain characteristics and fibrillogenesis. Th...

We have determined the N-termini of 26 proteins of the large ribosomal subunit from yeast mitochondria by direct amino acid micro-sequencing. The N-terminal sequences of proteins YmL33 and YmL38 showed a significant similarity to eubacterial ribosomal (r-) proteins L30 and L14, respectively. In ...