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(S) 2 (2 Chloro­quinolin 3 yl) 2 [(S) α methylbenzyl­amino]aceto­nitrile

(S) 2 (2 Chloro­quinolin 3 yl) 2 [(S) α methylbenzyl­amino]aceto­nitrile

Quinolines are an important group of heterocyclic compounds. Among these, 2-chloro-3-formylquinolines occupy a prominent position as they are key intermediates for further ()-annelation of a wide variety of rings and for various functional group interconversions (Meth-Cohn, 1993). Particular interest in quinoline derivatives arises owing to their biological activity, namely as antibiotics (Jackson & Meth-Cohn, 1995; Kansagra et al., 2000), anti-inflammatories (Schroderet, 1989), anti-tumourals (Joseph et al., 2002)), anti- oxidants (Laalaoui et al., 2003) and analgesics (Heide et al., 1986; Solomon, 1970). In the same way, -aminoacids are of great biological and economic importance (Williams, 1989). The asymmetric Strecker reaction is one of the most important methods for the synthesis of enantiomerically pure -amino- nitrile derivatives, which are useful intermediates for the synthesis of -aminoacids. The use of (S)-()--methyl- benzylamine-derived aldimines has a significant role in the diastereoselective Strecker synthesis (Bhanu-Prasad et al., 2004).
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(+) (S,S) 1,3 Bis[(tetra­hydro­furan 2 yl)­meth­yl]thio­urea

(+) (S,S) 1,3 Bis[(tetra­hydro­furan 2 yl)­meth­yl]thio­urea

heterocycle-substituted thiourea synthesized under solvent- free conditions. The thiourea unit adopts a ZZ conformation, with the HN—(C S)—NH core almost planar and the tetrahydrofurfuryl groups placed below and above this plane. The whole molecule thus approximates to noncrystallographic C 2 symmetry. Unexpectedly, the C S group is not involved in

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[2 Carb­­oxy 2,2′,2′′ nitrilo­tris­(ethane­thiol­ato) κ4N,S,S′,S′′](tri­phenyl­phosphine κP)rhenium(III) acetone solvate

[2 Carb­­oxy 2,2′,2′′ nitrilo­tris­(ethane­thiol­ato) κ4N,S,S′,S′′](tri­phenyl­phosphine κP)rhenium(III) acetone solvate

Fig. 3 shows the linkage of two molecules via hydrogen bonds between the carboxyl groups, forming a dimer in the crystal structure. There are four possibilities for this dimer formation, namely linkage of two 20(R) molecules, 20(S) pairs, and two different combinations of 20(R) and 20(S) molecules, disordered over the centre of symmetry of the space group. The corresponding symmetry-independent hydrogen bonds are given in Table 2. From the geometry of the hydrogen bonds, it can be concluded that the formation of 20(R)–20(R) and 20(S)–20(S) dimers is energetically favoured. Never- theless, the refinement of (I) in the space group P1 as an ordered twinned structure with two symmetry-independent molecules gave no satisfactory results.
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(S) 2 (Pyrrolidinium 2 ylmethyl­sulfan­yl)pyridinium dibromide

(S) 2 (Pyrrolidinium 2 ylmethyl­sulfan­yl)pyridinium dibromide

anions. The chiral atom C1 has the expected S conformation, and the C1/C3/C4/N1 atoms of pyrrolidine are almost coplanar. The distance of atom C2 to the C1/C3/C4/N1 mean plane is 0.484 (5) Å, while the distance of atom C5 to the plane is 0.865 (9) Å. In addition, the dihedral angle of the C1/N1/C3/C4 mean plane and the pyridine ring is 67.82 (4) °. The thioether group connects the pyridine ring and the 2-methylpyrrolidine group, the torsion angle of C6—S1—C5—C1 is 97.13 (4) °.

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(S,S) 1,2 Bis(1 methyl­benzimidazol 2 yl) 1′,2′ bis­­(meth­oxy)ethane

(S,S) 1,2 Bis(1 methyl­benzimidazol 2 yl) 1′,2′ bis­­(meth­oxy)ethane

stereogenic centers whose con®gurations are S, as determined by the starting material in the synthetic procedure, l(+) tartaric acid. These atoms yield a vector skewed with respect to the benzimidazole plane, as evidenced by the torsion angles N11ÐC12ÐC1ÐC1 iii and N13ÐC12ÐC1ÐC1 iii [85.2 (2)

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(S,S) N,N′ Di­cyano­ethyl 1,2 (2 hydroxyphenyl)ethyl­enedi­amine

(S,S) N,N′ Di­cyano­ethyl 1,2 (2 hydroxyphenyl)ethyl­enedi­amine

1,2-(2-Hydroxyphenyl)-1,2-ethylenediamine was synthesized according to the literature procedure of Mu¨ller et al. (1989). Acrylonitrile (0.67 ml, 10.2 mmol) was added to a solution of (S,S)- 1,2-(2-hydroxyphenyl)-1,2-ethylenediamine (1 g, 4.1 mmol) dissolved in methanol (14 ml). The mixture was stirred for 48 h at room temperature. After removal of the solvent, diethyl ether was added and the resulting solution was allowed to stand at room temperature for 3 d to give yellow crystals of (3). Spectroscopic analysis: 1 H NMR

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Bis­[N (2 hy­droxy­ethyl) N methyl­di­thiocarbamato S,S′]­di­phenyl­tin

Bis­[N (2 hy­droxy­ethyl) N methyl­di­thiocarbamato S,S′]­di­phenyl­tin

A solution of carbon disul®de in methanol was added to a mixture of diphenyltin dichloride and 2-hydroxyethylmethylamine (1:2 molar stoichiometry) at 277 K. The mixture was stirred to afford a pale- yellow solid, which was collected and recrystallized from a methanol/ chloroform mixture to afford the title compound (m.p. 401±402 K). Elemental analysis, found (calculated) for C 20 H 26 N 2 O 2 S 4 Sn: C 40.40

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Bis­[μ N,N bis­(2 hy­droxy­ethyl)­di­thio­carbamato] 1:2κ3S,S′:S′;2:1κ3S,S′:S′ bis­{[N,N bis­(2 hy­droxy­ethyl)­di­thio­carbamato κ2S,S′]­cadmium(II)}

Bis­[μ N,N bis­(2 hy­droxy­ethyl)­di­thio­carbamato] 1:2κ3S,S′:S′;2:1κ3S,S′:S′ bis­{[N,N bis­(2 hy­droxy­ethyl)­di­thio­carbamato κ2S,S′]­cadmium(II)}

Monomeric, dimeric, cyclotetrameric, polymeric, two-dimen- sional and three-dimensional structures are all featured amongst the zinc-triad 1,1-dithiolates (Tiekink, 2002). The challenge is to rationalize the fascinating structural diversity and some progress has been made to achieve that aim (e.g. Cox & Tiekink, 1999; Lai et al., 2002; Tiekink, 2003; Lai et al., 2004). The structure of the title compound, (I), a known species (Pages et al., 1985; Marino et al., 1999), has been ex- amined in this context and found to adopt the common structural type found for compounds of the general formula [Cd(S 2 CNR 2 ) 2 ] 2 (Tiekink, 2003). Thus, the centrosymmetric
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S,S′ (But 2 yne 1,4 diyl)­bis­(L cysteine) monohydrate

S,S′ (But 2 yne 1,4 diyl)­bis­(L cysteine) monohydrate

It is widely known that l-cysteine and its derivatives exhibit remarkable bioactivities, which prompted us to synthesize new compounds containing two or more cysteine groups and investigate the relationships between structure and bioactiv- ities. A few compounds containing two cysteine moieties bridged through their S atoms via different hydrocarbon diyls have been reported (Armstrong & Vigneaud, 1947; Struhar et al., 1975; Hu et al., 1999); however, the crystal structures of these derivatives are rarely studied (Bigoli et al., 1982; Shi et al., 2002). We report herein the crystal structure of a new compound S,S 0 -(but-2-yne-1,4-diyl)bis(l-cysteine) mono-
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μ Ferrio bis­{carbonyl­[μ 2,2′,2′′ nitrilo­tri­ethane­thiol­ato(3 ) N,S,S′,S′′:S,S′]­iron(II)} benzene solvate

μ Ferrio bis­{carbonyl­[μ 2,2′,2′′ nitrilo­tri­ethane­thiol­ato(3 ) N,S,S′,S′′:S,S′]­iron(II)} benzene solvate

removed by ®ltration; to the ®ltrate was added iron pentacarbonyl (1.49 g, 7.61 mmol) and the mixture left to stand for a further 3 d. The dark crystalline needles which formed were collected by ®ltration, washed repeatedly with diethyl ether and dried in vacuo. Expected for C 20 H 3 Fe 3 N 2 O 2 S 6 : C 34.8, H 4.4, N 4.1, Fe 24.3%; found: C 34.9, H

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Supplementary Figures S-2 General experimental procedures S-4 Chemical synthesis of compounds 2-6 S-4 MIC assay S-7 Viability assay S-8 Cytotoxicity assay S-9 References S-10 NMR, IR and HRMS spectra S-11

Supplementary Figures S-2 General experimental procedures S-4 Chemical synthesis of compounds 2-6 S-4 MIC assay S-7 Viability assay S-8 Cytotoxicity assay S-9 References S-10 NMR, IR and HRMS spectra S-11

density of 0.05 (calibration curve series) and 0.1 (exposure). For exposure, 20 μL of the 10× compound preparation in an appropriate solvent was transferred to 180 μL of the bacterial culture, yielding 1× concentration of the compound for exposure. The plate was then incubated in the plate reader at room temperature and constant shaking for 2 hours. Afterwards, 5 μL of the exposure mixture were added to 195 μL of fresh LB to dilute the antibiotic and allow remaining bacterial cells to outgrow. The same outgrowth procedure was performed for the calibration series. As a last step, the plate was incubated for 16 hours in the plate reader at 37 °C with OD 600 measurements every 20 min preceded by 30 s of shaking.
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(S) 2 Amino 1 (pyrrolidinium 2 ylmeth­yl)pyridinium dibromide

(S) 2 Amino 1 (pyrrolidinium 2 ylmeth­yl)pyridinium dibromide

Proline and its derivatives have been extensively studied due to their abilities to catalyze a wide range of reactions as organocatalysts in recent years (Ishii et al. , 2004; Xu et al. , 2006). The title compound, which could be readily synthesized from commercially available L -proline and 2-aminopyridine, can act as organocatalyst in the Michael addition of ketones to nitrostyrenes. These reactions afford the desired Michael adducts in good yields and moderate enantioselectivities. The title salt ( S )-2-amino-1-(pyrrolidinium-2-ylmethyl)-pyridinium dibromide crystal structure (Fig. 1) is built of pyrrolidinium cations and bromide anions. The pyrrolidinium ring displays a fair half-chair conformation, with the flap atom N1 lying 0.564 (6) Å from the mean plane of C1/C2/C3/C4. The methylene C5 atom, which connects the pyrrolidinium ring and the 2-aminopyridine group, is displaced from the plane of four pyrrolidinium carbons by 0.811 (8) Å in the same direction as the N1 atom. The atom N3 of the amino group of pyrrolidinium and the atom N1 are on the opposite sides of the mean plane of C1/C2/C3/C4.
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(S) N Nitro­soazetidine 2 carboxyl­ic acid

(S) N Nitro­soazetidine 2 carboxyl­ic acid

N-Nitrosamines are of widespread interest due to their strong carcinogenic and mutagenic properties (Loeppky & Outram, 1982). Since the molecular geometry of these compounds critically in¯uences their biological activity, the stereo- chemistry of N-nitrosamines has been studied using various experimental techniques (PoøonÂski et al., 1996, and references therein). Particularly, non-planarity and, connected with it, inherent chirality of the N-nitrosamine chromophore strongly in¯uence the circular dichroism spectra (Shustov et al., 1992). As a correct interpretation of these spectra is assisted by a detailed knowledge of the chromophore geometry, we performed an X-ray crystallographic study of (S)-N-nitro- soazetidine-2-carboxylic acid, (I). The N atom of the N- nitrosamino group in (I) is included in the strained four- membered ring that may lead to its pyramidal con®guration and the intrinsic chirality of the chromophore (Shustov & Rauk, 1995). Additionally, due to a restricted rotation about the partially double NÐN bond, the molecules of (I) can exist as either the E or Z stereoisomer. In aqueous solution, the equilibrium between these two forms is shifted towards the E conformer (Gaf®eld et al., 1981).
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(S) 2 [(S) 2 Acetamido 3 phenyl­propanamido] 3 phenyl­propanoic acid

(S) 2 [(S) 2 Acetamido 3 phenyl­propanamido] 3 phenyl­propanoic acid

A mixture of (S)-2-amino-3-phenylpropanoic acid (0.1 mol), acetic anhydryde (0.2 mol) in water (30 ml) was stirred for 20 min at 298 K. After cooling, filtration and drying, the title compound was obtained. 10 mg of (I) was dissolved in 10 ml ethanol–N,N-dimethylacetamide (1:1 v/v) and the solution was allowed to evaporate at room temperature. Colourless single crystals of the title compound were formed after 35 d.

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Production of (S)-2-aminobutyric acid and (S)-2-aminobutanol in Saccharomyces cerevisiae

Production of (S)-2-aminobutyric acid and (S)-2-aminobutanol in Saccharomyces cerevisiae

As (S)-2-aminobutyric acid is critical for production of (S)-2-aminobutanol, we focused on boosting the bio- synthesis of this compound. To investigate the kinetic coupling of the two heterologous enzymatic steps of the (S)-2-ABA pathway, we first determined the amount of 2-ketobutyric acid in strains previously analyzed for (S)- 2-ABA production (Fig. 2). Combining ScCHA1 with any of the six enzymes for the second step of the pathway does not lead to detectable amounts of 2-ketobutyric acid. In contrast, combining EcILVa with any of the six enzymes for the second enzymatic step resulted in 2-ketobutyric acid accumulation in the range of 0.1  mg/L, except for the combination EcILVa and ScGDH1 ′ where no 2-keto- butyric acid could be detected (Fig.  5a). The highest accumulation of 2-ketobutyric acid (0.98  ±  0.03  mg/L) was observed with threonine deaminase (SlTD) from S. lycopersicum combined with EcGDH’ (Fig.  5b). We con- cluded that in the case of the S. lycopersicum threonine deaminase, a more efficient enzymatic coupling between threonine deaminase and glutamate dehydrogenase may improve conversion of l-threonine to (S)-2-ABA.
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(S) N (1 Hy­droxy­methyl 2 methyl­prop­yl) 2 meth­oxy­benzamide

(S) N (1 Hy­droxy­methyl 2 methyl­prop­yl) 2 meth­oxy­benzamide

NaH (8.7 g, 60%, 0.216 mol) was added portionwise to a stirred solution of L-valinol (22.1 g, 0.215 mol) in dry THF (120 ml). The mixture was stirred at ambient temperature for 1 h. To this solution was added 2-Methoxy-benzoic acid methyl ester (17.8 g, 0.107 mol) dissolved in THF (50 ml). The mixture was refluxed for 12 h under nitrogen, quenched with H 2 O (10 ml) and concentrated by evaporation of the solvent. The residue was dissolved in CH 2 Cl 2 (100 ml), washed

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Crystal structure of (S) 2 amino 2 methyl­succinic acid

Crystal structure of (S) 2 amino 2 methyl­succinic acid

For general background and biological properties of 2-methylaspartic acid (MeASP), see: Pfeiffer & Heinrich (1936); Delbaere et al. (1989); Nobe et al. (1998). For the absolute configuration and synthesis of the title compound, see: Terashima et al. (1966). For the crystal structure of related racemic compounds, see: Derricott et al. (1979); Brewer et al. (2013). For the crystal structure of dl -ASP, see: Flaig et al. (1998).

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Methyl (2′S,3′S) 3,4 O (2′,3′ di­meth­oxy­butane 2′,3′ di­yl) α L rhamno­pyran­oside: a glycosyl acceptor

Methyl (2′S,3′S) 3,4 O (2′,3′ di­meth­oxy­butane 2′,3′ di­yl) α L rhamno­pyran­oside: a glycosyl acceptor

ketalization of methyl l -(+)-rhamnopyranoside with 2,3- butanedione. It crystallizes with two molecules in the asymmetric unit, which are connected by O—H O hydrogen bonds. The C-3,4 diequatorial hydroxy groups of the methyl l -(+)-rhamnopyranoside were protected, leaving the C-2 hydroxy group free. The l -(+)-rhamnopyranoside and 2 0 ,3 0 - dimethoxybutane-2 0 ,3 0 -diyl rings adopt chair conformations

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6(S) Methyl 3(S) (1 methyl­ethyl)­piperazin 2 one

6(S) Methyl 3(S) (1 methyl­ethyl)­piperazin 2 one

The title chiral 3,6-disubstituted piperazin-2-one, (I), was obtained during the synthesis of a potential head group mimic of the naturally occurring bioactive lipid ceramide. The piperazinone skeleton has been used before as a conforma- tionally restricted analog in the synthesis of peptidomimetics (Kolter et al., 1995; Suarez-Gea et al., 1996; Schanen et al., 1996; Uchida & Achiwa, 1996). More recently, 4-N-alkylated piperazin-2-ones have been synthesized by a different route as conformationally rigid analogs of another bioactive lipid, viz. diacylglycerol (Endo et al., 1997). Compound (I) has been prepared from the protected, con®gurationally stable dipep- tide aldehyde (III) (Kolter et al., 1992) by hydrogenolysis. During this reaction, a reproducible deoxygenation of the 6- hydroxymethyl residue to a methyl group occurs as an unex- pected side reaction in about 20% yield. Similar results have been obtained with a starting material in which the isopropyl group is replaced by a benzyl residue (not shown). The mechanism of this reaction is not clear, but the identity of the deoxygenated compound (I) was con®rmed by this crystal- lographic investigation. Furthermore, the crystal structure gives information on the three-dimensional structure of the piperazinone scaffold and the in¯uence of ring substituents on the ring conformation (Michel et al., 1987).
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(S) 4,16 Di­hy­droxy­methyl [2 2]­para­cyclo­phane bis (1S) camphanoate

(S) 4,16 Di­hy­droxy­methyl [2 2]­para­cyclo­phane bis (1S) camphanoate

Molecular dimensions are normal (cf. the structure of another paracyclophane camphanoyl derivative; Tochtermann et al., 1987). The side chain conformations are de®ned by the torsion angles in Table 1; these are antiperiplanar in the regions C17ÐO17ÐC19 and C18ÐO18ÐC29. The molecules are connected by a series of CÐH O contacts that could be considered as weak hydrogen bonds. Table 2 shows all such contacts with H O < 2.6 AÊ; all operate by translation parallel to the b axis, forming columns of molecules (Fig. 2).

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