Project description:(3S)-Acetoin and (2S,3S)-2,3-butanediol are important platform chemicals widely applied in the asymmetric synthesis of valuable chiral chemicals. However, their production by fermentative methods is difficult to perform. This study aimed to develop a whole-cell biocatalysis strategy for the production of (3S)-acetoin and (2S,3S)-2,3-butanediol from meso-2,3-butanediol. First, E. coli co-expressing (2R,3R)-2,3-butanediol dehydrogenase, NADH oxidase and Vitreoscilla hemoglobin was developed for (3S)-acetoin production from meso-2,3-butanediol. Maximum (3S)-acetoin concentration of 72.38 g/L with the stereoisomeric purity of 94.65% was achieved at 24 h under optimal conditions. Subsequently, we developed another biocatalyst co-expressing (2S,3S)-2,3-butanediol dehydrogenase and formate dehydrogenase for (2S,3S)-2,3-butanediol production from (3S)-acetoin. Synchronous catalysis together with two biocatalysts afforded 38.41 g/L of (2S,3S)-butanediol with stereoisomeric purity of 98.03% from 40 g/L meso-2,3-butanediol. These results exhibited the potential for (3S)-acetoin and (2S,3S)-butanediol production from meso-2,3-butanediol as a substrate via whole-cell biocatalysis.
Project description:In the title mol-ecule, C15H12O3, the C atoms bearing the hy-droxy group and the phenyl ring are disordered over two sets of sites with refined occupancies of 0.573 (7) and 0.427 (7). There is also disorder of the phenyl ring but the hy-droxy group was refined as ordered. The dihedral angles between the benzene ring of the chromane ring system and the phenyl ring are 89.7 (2)° for the major component of disorder and 72.1 (3)° for the minor component. Both disorder components of the the di-hydro-pyran ring are in a half-chair conformation. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming inversion dimers with an R 2 (2)(10) graph-set motif. Weak C-H⋯π inter-actions link these dimers into ladders along [001].
Project description:The title compound (trivial name moexipril hydro-chloride) crystallizes as the aceto-nitrile monosolvate, C27H35N2O7 (+)·Cl(-)·C2H3N, with the salt comprising a U-shaped cation and a chloride anion. The conformation of the cation is stabilized by a weak intra-molecular N(+)-H⋯O hydrogen bond and the tetra-hydro-pyridine ring adopts a boat conformation. The dihedral angle between the planes of the benzene rings is 85.6 (1)°. In the crystal, the cations and anions form tight ionic pairs by strong inter-molecular O-H⋯Cl hydrogen bonds. C-H⋯Cl and C-H⋯N hydrogen bonds link these ionic pairs and the aceto-nitrile solvate mol-ecules into puckered layers parallel to (100).
Project description:In the title compound, C(17)H(18)NO(2) (+)·Cl(-)·H(2)O, a precursor to novel asymmetric catalysts, the N-containing six-membered ring of the tetra-hydro-quinolinium unit assumes a half-boat conformation. In the crystal, inter-molecular O-H⋯O, O-H⋯Cl, N-H⋯Cl and C-H⋯O hydrogen bonds and C-H⋯π inter-actions link the mol-ecules into a three-dimensional network.
Project description:The title mol-ecular salt, C6H9N2 (+)·C4H5O6 (-)·H2O, crystallized with two 2-amino-4-methyl-pyridin-1-ium cations, two l-(+)-tartaric acid monoanions [systematic name: (2R,3R)-3-carb-oxy-2,3-di-hydroxy-propano-ate] and two water mol-ecules in the asymmetric unit. In the crystal, the cations, anions and water mol-ecules are linked via a number of O-H⋯O and N-H⋯O hydrogen bonds, and a C-H⋯O hydrogen bond, forming a three-dimensional structure.
Project description:(2S,3S)-2,3-Butanediol ((2S,3S)-2,3-BD) is a potentially valuable liquid fuel and an excellent building block in asymmetric synthesis. In this study, cofactor engineering was applied to improve the efficiency of (2S,3S)-2,3-BD production and simplify the product purification. Two NADH regeneration enzymes, glucose dehydrogenase and formate dehydrogenase (FDH), were introduced into Escherichia coli with 2,3-BD dehydrogenase, respectively. Introduction of FDH resulted in higher (2S,3S)-2,3-BD concentration, productivity and yield from diacetyl, and large increase in the intracellular NADH concentration. In fed-batch bioconversion, the final titer, productivity and yield of (2S,3S)-2,3-BD on diacetyl reached 31.7 g/L, 2.3 g/(L·h) and 89.8%, the highest level of (2S,3S)-2,3-BD production thus far. Moreover, cosubstrate formate was almost totally converted to carbon dioxide and no organic acids were produced. The biocatalytic process presented should be a promising route for biotechnological production of NADH-dependent microbial metabolites.
Project description:In the title compound, C(26)H(32)N(2), the cyclo-hexane and piperazine rings each adopt a chair conformation. Both phenyl rings and the two propen-3-yl residues are in equatorial positions. There are no C-H⋯N hydrogen bonds nor π-π inter-actions between the aromatic rings. The absolute configuration was assigned with reference to the starting material.
Project description:In the title hydrated mol-ecular salt, C8H12N(+)·C6H4NO3 (-)·H2O, the conformation of the side chain in the cation is anti [C-C-C-N = 179.62 (12)°] and the dihedral angle between the aromatic ring and the nitro group in the anion is 3.34 (11)°. In the crystal, the components are linked by O-H⋯O and N-H⋯O hydrogen bonds, generating (10-1) sheets, which feature R 4 (4)(21) loops. The sheets inter-act by weak aromatic π-π stacking inter-actions [centroid-centroid distance = 3.896 (3) Å], forming a three-dimensional network.
Project description:The title compound, C(12)H(19)N(2) (+)·Cl(-)·H(2)O, contains a network of 4-(2,3-dimethyl-phen-yl)piperazin-1-ium cations, water mol-ecules and chloride anions. The crystal packing is influenced by O-H⋯Cl, N-H⋯Cl, N-H⋯O, C-H⋯O and C-H⋯Cl hydrogen bonds, resulting in structure with an open-framework architecture.
Project description:The title salt, C3H6N3S2 (+)·Cl(-)·H2O, crystallized with two organic cations, two chloride anions and two water mol-ecules in the asymmetric unit. The methyl C atoms deviate from their respective bound ring planes by 0.081 and 0.002 Å. In the crystal, the components are connected via N-H⋯O, N-H⋯Cl and O-H⋯Cl hydrogen bonds, forming sheets lying parallel to (100). The sheets are linked into bilayers by O-H⋯Cl hydrogen bonds involving the chloride ions and water mol-ecules. Within the bilayers there are π-π inter-actions [inter-centroid distances = 3.4654 (4) and 3.4789 (4) Å] involving inversion-related cations.