Isolation of 2-Isopropyl-4,4-dimethyl-5-vinylidene-2-cyclopenten-1-one and 2-Isopropyl-3-isopentyl-maleic Anhydride from the Pyrolytic Products of 2-Isopropylmalic acid

(R)-[2-¹⁴C]-Mevalonic acid (MVA) lactone was incorporated into (-)-4′-hydroxy-y-ionylideneacetic acid (4?-hydroxy-y-acid), which was first isolated from the culture broth of Cercospora cruenta. 4?-Hydroxy-γ-acid was then metabolized to (+)-(2Z,4E)-4′-oxo-α-ionylideneacetic acid and (+)-(2Z,4E)-′14′-dihydroxy-γ-ionylideneacetic acid. The latter was converted to (+)-abscisic acid (ABA) with a high incorporation ratio by the fungus.     

Synthesis of Streptovitacin-C2 Isomers

(2R*,4S*,6S*,αS*)- and (2R,4R,6R,αS)-Streptovitacin-C₂ (STV-C₂) (1a and 1b) were synthesized by an aldol condensation of (2R*,4S*)- or (2R,4R)-2,4-dimethyl-2-trimethylsiloxy-1-cyclohexanone (15a or 15b) with 4-(2-oxoethyl)-2,6-piperidinedione (16), which was followed by desilylation of the products. The stereochemistry of the synthesized STV-C₂ isomers (1a and 1b) was elucidated by NMR. STV-C₂ isomers (1a and 1b) did not show strong antimicrobial activity against Saccharomyces cerevisiae and Pyricularia oryzae.     

Syntheses of 2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and Its (2S,3R)-Isomer

2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and its (2S,3R)-isomer were respectively synthesized from allyl 2-[(2R,3S)-3-(benzyloxycarbonyloxy)-2-fluorotetradecanamido]-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranoside and its corresponding (2S,3R)-isomer. Both target compounds did not activate macrophage, but the (2S,3R)-analogue strongly inhibited the binding of LPS to macrophage.     

Antimicrobial activities of 2-arylthio-N-alkylmaleimides

Summary A variety of 2-arylthio-N-alkylmaleimides were prepared, and their antimicrobial activities were examined. Almost all of these compounds exhibited antibacterial activity against Gram-positive bacteria such asBacillus subtilis andStaphylococcus aureus. Some compounds such as 2-(halogeno-phenyl)-thio-N-methylmaleimides (4, 5, 6, 8 and 10) and 2-(2-carbamoylphenyl)thio-N-methylmaleimide(35) exhibited antibacterial activity againstEscherichia coli. All compounds tested were inactive againstPseudomonas aeruginosa except 2-(2-carbamoylphenyl)thio-N-methylmaleimide(35) which was marginally active. Activities against Gram-positive bacteria were not due to the effect of the substituent on the benzene ring, except in the instances 2-carboxy, 2-carbomethoxy, 2-amino groups and alkyl chains, however, activities against Gram-negative bacteria were due to phenylthio and the alkyl substituents. Some of 2-arylthio-N-alkylmaleimides were examined for their antifungal activities using eight strains of fungi, and they showed activity against these.     

Tetranitromethane modification of photosystem 2

Inhibition of photosystem 2 by the peptide-modification reagent, tetranitromethane, has been investigated with spinach digitonin particles. In the presence of tetranitromethane, (1) the initial fluoresence yield is suppressed with a concomitant elimination of the variable component of fluorescence; (2) the optical absorption transient at 820 nm, attributed to P680⁺, is greatly attenuated; (3) diphenylcarbazide-supported photoreduction of dichlorophenol indophenol is abolished; and (4) electron spin resonance Signal 2f and Signal 2s are eliminated. These results are consistent with multiple sites of modification in photosystem 2 by tetranitromethane, and suggest further that this reagent can inhibit charge stabilization in the reaction center.Abbreviations D₁ electron donor to P680⁺ in oxygen-inhibited photosystem 2 preparations - DPIP 2,6-dichlorophenol indophenol - esr electron spin resonance - F_i initial chlorophyll a fluorescence yield - F_max maximum chlorophyll a fluorescence yield - F_v variable chlorophyll a fluorescence yield - FWHM full width at half maximum - Mes 2-(N-morpholino)ethanesulfonic acid - P680 primary electron donor chlorophyll of photosystem 2 - Ph pheophytin - PS 2-photosystem 2 - Q_a primary quinone electron acceptor - Q_b secondary quinone acceptor - Tricine N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine - TNM tetranitromethane     

Stereoselective reduction of 2-substituted cyclohexanones by Saccharomyces cerevisiae

A comparative study of two modifications of enzymic reduction of ethyl N-{2-{4-[(2-oxo-cyclohexyl)methyl]phe- noxy}ethyl} carbamate (1), an insect juvenile hormone bioanalog, was performed using Saccharomyces cerevisiae in two bioreactors of different size, 250-ml shake-flask and 1-l fermenter. The two major products of this reduction were obtained in 45–49% (w/w) yields but with > 99% enantiomeric purity. Their absolute configurations were assigned as ethyl (1S,2S)-N-{2-{4-[(2-hydroxycyclohexyl)methyl]phenoxy}ethyl}carbamate (2a) and ethyl (1R,2S)-N-{2-{4-[(2-hydroxycyclohexyl)methyl]phenoxy}ethyl}carbamate (3a).     

Synthesis of Glycoglycerolipids: 3-O-Mannooligosyl-l,2-di-O-tetradecyl-sn-glycerol

Synthetic routes for the following mannooligosylglycerolipids of biological interest were developed by using regioselectively protected monosaccharide synthons and l,2-di-O-alkyl-sn-glycerol; 3-O-(2-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-l,2-di-O-tetradecyl-sn-glycerol; 3-O-[2-O-(2-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-α-D-mannopyranosyl]-l,2-di-O-tetradecyl-sn-glycerol; 3-O-(6-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-l,2-di-O-tetradecyl-sn-glycerol; and 3-O-(3,6-di-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-1,2-di-α-tetradecyl-sn-glycerol.     

β-N-Acetylhexosaminidase-catalysed synthesis of non-reducing oligosaccharides

A large panel of fungal β-N-acetylhexosaminidases was tested for the regioselectivity of the β-GlcNAc transfer onto galacto-type acceptors ( -galactose, lactose, 2-acetamido-2-deoxy- -galactopyranose). A unique, non-reducing disaccharide β- -GlcpNAc-(1→1)-β- -Galp and trisaccharides β- -GlcpNAc-(1→4)-β- -GlcpNAc-(1→1)-β- -Galp, β- -Galp-(1→4)-β- -Glcp-(1→1)-β- -GlcpNAc and β- -Galp-(1→4)-α- -Glcp-(1→1)-β- -GlcpNAc were synthesised under the catalysis of the β-N-acetylhexosaminidase from the Aspergillus flavofurcatis CCF 3061 with -galactose and lactose as acceptors. The use of 2-acetamido-2-deoxy- -galactopyranose as an acceptor with the β-N-acetylhexosaminidases from A. flavofurcatis CCF 3061, A. oryzae CCF 1066 and A. tamarii CCF 1665 afforded only β- -GlcpNAc-(1→6)- -GalpNAc.     

Purification of a stereospecific 2-ketoreductase from Gluconobacter oxydans

The 2-ketoreductase from Gluconobacter oxydans (SC 13851) catalyzes the reduction of 2-pentanone to (S)-(+)-2-pentanol. The 2-ketoreductase was purified 295-fold to homogeneity from G. oxydans cell extracts. The purified 2-ketoreductase had a molecular mass of 29 kDa with a specific activity of 17.7 U/mg. (S)-(+)-2-pentanol was prepared on a pilot scale (3.2 kg of 2-pentanone input) using Triton X-100-treated G. oxydans cells. After 46 h, 1.06 kg (32.3 M%) of (S)-(+)-2-pentanol of >99% enantiomeric excess (ee) was produced. Journal of Industrial Microbiology & Biotechnology (2000) 25, 171–175. Received 01 May 2000/ Accepted in revised form 28 June 2000     

Structure of the O-specific polysaccharide of the marine bacterium Arenibacter palladensis KMM 3961T containing 2-acetamido-2-deoxy-L-galacturonic acid

The O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the marine bacterium Arenibacter palladensis type strain KMM 3961^T and studied by chemical methods and ¹H and ¹³C NMR spectroscopy including 2D COSY, TOCSY, ¹H,¹³C HSQC, and HMBC experiments. The polysaccharide was shown to consist of tetrasaccharide repeating units containing two mannose residues (Man), one 2-acetamido-2-deoxy-D-galactose residue (D-GalNAc), and one 2-acetamido-2-deoxy-L-galacturonic acid residue (L-GalNAcA) and having the following structure: ? 2) - a- D - Manp - (1 ? 6) - a- D - Manp - (1 ? 4) - a- L - GalpNAcA - (1 ? 3) - b- D - GalpNAc - (1 ?\to 2) - \alpha - D - Manp - (1 \to 6) - \alpha - D - Manp - (1 \to 4) - \alpha - L - GalpNAcA - (1 \to 3) - \beta - D - GalpNAc - (1 \to.     

The relationship between theH-2 loss mutations ofH-2da andH-2db in the mouse

The mouse strain B10.D2-H-2^da carries the mutantH-2^da allele, derived after chemical induction, and this has been shown to be a gain and loss mutation involving theH-2D^d locus.BALB/c- H-2^db, derived spontaneously, is a loss mutation only, and appears not to involve theH-2D^d, but rather theH-2L^d locus. The two mutations effectboth graft rejection and serologically detected H-2 specificities (Type II mutation). In the experiments described in this study, theloss mutations in theH-2^da andH-2^db mutants have been compared by skin grafting, and by direct and absorption serological techniques: (1) By skin grafting, using the well established complementation method, it has been shown thatH-2^da andH-2^db do not complement each other, i.e., the mutation in both occurred at the same locus. However, by appropriate selection of donor and recipient, it has become clear thatH-2^da had a greater loss than didH-2^db, althoughH-2^da includes the loss found inH-2^db. (2) Serological studies have demonstrated that H-2D.4 was altered inH-2^da, but not inH-2^db; H-2.28 (detected by D-28b and D-29) was decreased or lost in both mutants;H-2^db anti-BALB/c failed to react withH-2^da; both mutants reacted similarly with D-28 sera. In addition, sera made usingH-2^da as donor did not contain an anti-H 2.28 antibody. The loss mutation involvingH-2^da therefore appears to have led also to the loss of H-2.28 as found inH-2^db. We conclude that theH-2^da strain arose after a complex mutation or recombination event which involvedboth theH-2D^d locus and the closely linkedH-2L^d locus, whereasH-2^db affects only theH-2L locus.     

A novel S-enantioselective amidase acting on 3,3,3-trifluoro-2-hydroxy-2-methylpropanamide from Arthrobacter sp. S-2

A novel S-enantioselective amidase acting on 3,3,3-trifluoro-2-hydroxy-2-methylpropanamide was purified from Arthrobacter sp. S-2. The enzyme acted S-enantioselectively on 3,3,3-trifluoro-2-hydroxy-2-methylpropanamide to yield (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropanoic acid. Based on the N-terminal amino acid sequence of this amidase, the gene coding S-amidase was cloned from the genomic DNA of Arthrobacter sp. S-2 and expressed in an Escherichia coli host. The recombinant S-amidase was purified and characterized. Furthermore, the purified recombinant S-amidase with the C-His₆-tag, which was expressed in E. coli as the C-His₆-tag fusion protein, was used in the kinetic resolution of (±)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide to obtain (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropanoic acid and (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide.     

Characterization of (2S,2'R,3'R)-2-(2',3'-[3H]-Dicarboxycyclopropyl)glycine Binding in Rat Brain

Abstract: [(2S,2′R,3′R)-2-(2′,3′-[³H]Dicarboxycyclopropyl)glycine ([³H]DCG IV) binding was characterized in vitro in rat brain cortex homogenates and rat brain sections. In cortex homogenates, the binding was saturable and the saturation isotherm indicated the presence of a single binding site with a K_D value of 180 ± 33 nM and a B_max of 780 ± 70 fmol/mg of protein. The nonspecific binding, measured using 100 µM LY354740, was <30%. NMDA, AMPA, kainate, l (?)-threo-3-hydroxyaspartic acid, and (S)-3,5-dihydroxyphenylglycine were all inactive in [³H]DCG IV binding up to 1 mM. However, several compounds inhibited [³H]DCG IV binding in a concentration-dependent manner with the following rank order of potency: LY341495 = LY354740 > DCG IV = (2S,1′S,2′S)-2-(2-carboxycyclopropyl)glycine > (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid > (2S,1′S,2′S)-2-methyl-2-(2-carboxycyclopropyl)glycine > l -glutamate = ibotenate > quisqualate > (RS)-α-methyl-4-phosphonophenylglycine = l (+)-2-amino-3-phosphonopropionic acid > (S)-α-methyl-4-carboxyphenylglycine > (2S)-α-ethylglutamic acid > l (+)-2-amino-4-phosphonobutyric acid. N-Acetyl-l -aspartyl-l -glutamic acid inhibited the binding in a biphasic manner with an IC₅₀ of 0.2 µM for the high-affinity component. The binding was also affected by GTPγS, reducing agents, and CdCl₂. In parasagittal sections of rat brain, a high density of specific binding was observed in the accessory olfactory bulb, cortical regions (layers 1, 3, and 4 > 2, 5, and 6), caudate putamen, molecular layers of the hippocampus and dentate gyrus, subiculum, presubiculum, retrosplenial cortex, anteroventral thalamic nuclei, and cerebellar granular layer, reflecting its preferential (perhaps not exclusive) affinity for pre- and postsynaptic metabotropic glutamate mGlu2 receptors. Thus, the pharmacology, tissue distribution, and sensitivity to GTPγS show that [³H]DCG IV binding is probably to group II metabotropic glutamate receptors in rat brain.     

Synthesis of 2-Bromomethyl-3-Hydroxy-2-Hydroxymethyl-Propyl Pyrimidine and Theophylline Nucleosides Under Microwave Irradiation. Evaluation of Their Activity Against Hepatitis B Virus

Alkylation of 2-methylthiopyrimidin-4(1H)-one (1a) and its 5(6)-alkyl derivatives 1b–d as well as theophylline (7) with 2,2-bis(bromomethyl)-1,3-diacetoxypropane (2) under microwave irradia-tion gave the corresponding acyclonucleosides 1-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]-2-methyl-thio pyrmidin-4(1H)-ones 3a–d and 7-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]theophylline (8), which upon further irradiation gave the double-headed acyclonucleosides 1,1 ′-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis[(2-(methylthio)-pyrimidin-4(1H)-ones] 4a–c, and 7,7 ′-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis(theophylline) (9). The deacetylated derivatives were obtained by the action of sodium methoxide. The activity of deacetylated nucleosides against Hepatitis B virus was evaluated. Compound 5b showed moderate inhibition activity against HBV with mild cytotoxicity.     

Facile synthesis of (R)N-2-hydroxyacyl-L-cysteine derivatives: (R)N-2-hydroxyacyl transfer from enzymatically-synthesized (R)S-2-hydroxyacylglutathione derivatives to L-cysteine

Summary N-(R)-2-Hydroxyacyl-L-cysteine derivatives were conveniently synthesized by the reaction of the corresponding S-(R)-2-hydroxyacyl-glutathione with cysteine. The (R)2-hydroxyacyl group was transferred from the S-glutathionyl moiety to S-cysteinyl, forming the corresponding (R)S-2-hydroxyacylcysteine; this rearranged to the (R)N-hydroxyacylcysteine. These compounds have anti-proliferative activity associated with the inhibition ofde novo pyrimidine synthesis.Abbreviations TRIS tris(hydroxymethyl) aminomethane - DTNB 5,5-dithiobis(2-nitrobenzoic acid)     

Antitumor evaluation and molecular docking study of substituted 2-benzylidenebutane-1,3-dione, 2-hydrazonobutane-1,3-dione and trifluoromethyl-1H-pyrazole analogues

Abstract

A series of 2-(arylidene)-1-(4-chlorophenyl)-4,4,4-trifluorobutane-1,3-diones (2–4), 4-(arylidene)-3-(4-chlorophenyl)-5-(trifluoromethyl)-4H-pyrazoles (5–7), 1-(4-chlorophenyl)-4,4,4-trifluoro-2-(2-(aryl)hydrazono)butane-1,3-diones (8, 9), 3-(4-chlorophenyl)-4-(2-(aryl)hydrazono)-5-(trifluoromethyl)-4H-pyrazoles (10, 11), 2-((3-(4-chlorophenyl)-1-phenyl-5-(trifluoromethyl)-1H-pyrazol-4-yl)methylene)malononitrile (13), 2-((5-(4-chlorophenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methylene)cycloalkan-1-ones (14, 15) and 1-(aryl)-3-(5-(4-chlorophenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)prop-2-en-1-ones (16, 17) were designed, synthesized and evaluated for their in vitro antitumor activity. 1-(4-Chlorophenyl)-4,4,4-trifluoro-2-(2-(4-methoxyphenyl)hydrazono)butane-1,3-dione (8) showed potential and broad spectrum antitumor activity compared to the known drug 5-FU with GI₅₀, (6.61 and 22.60 µM), TGI (42.66 and <100?µM) and LC₅₀ (93.33 and <100?µM) values, respectively. On the other hand, compound 8 yielded selective activities toward melanoma, colon, non-small lung and breast cancer cell lines compared with erlotinib and gefitinib. Molecular docking methodology was performed for compound 8 into binding site of B-RAFV600E and EGFR kinases which showed similar binding mode to vemurafenib (PLX4032) and erlotinib, respectively.     

Synthesis and Properties of Modified Oligodeoxyribonucleotides Containing 2"-O-(2,3-Dihydroxypropyl)uridine and 2"-O-(2-Oxoethyl)uridine

A new uridine derivative, 2"-O-(2,3-dihydroxypropyl)uridine, and its 3"-phosphoramidite were obtained for direct introduction into oligonucleotides during automated chemical synthesis. Oligonucleotides 10 to 15 nt long harboring 2"-O-(2,3-dihydroxypropyl)uridine residues were synthesized; periodate oxidation of these oligomers gave oligonucleotides containing 2"-O-(2-oxoethyl)uridine residues. The presence of a reactive aldehyde group in 2" position of the carbohydrate moiety was confirmed by the interaction withp-nitrophenylhydrazine and methionine methyl ester. The thermostability of DNA duplexes containing modified units does not practically differ from that of the natural analogues.     

Production of 2-(2-phenylethyl) Chromones in Cell Suspension Cultures of <Emphasis Type="Italic">Aquilaria sinensis</Emphasis>

2-(2-Phenylethyl) chromones are the major constituents responsible for the quality of agarwood, which is one of the most valuable non-timber products used as incenses, perfumes, traditional medicines and other products. In this study, cell suspension culture of Aquilaria sinensis (Lour) Gilg was used to monitor the eliciting effects of crude fungal extracts on cell growth and chromones production. Crude extracts of Melanotus flavolivens (B. etc) Sing. prepared with different solvents were used to elicit the production of 2-(2-phenylethyl) chromones in cell suspension cultures of A. sinensis. Four 2-(2-phenylethyl) chromones,␣6,7-dimethoxy-2-(2-phenylethyl) chromone (1), 6,7-dimethoxy-2-[2-(4′-methoxyphenyl)ethyl] chromone (2), 6-methoxy-2-[2-(4′-methoxyphenyl)ethyl] chromone (3) and 6-methoxy-2-(2-phenylethyl) chromone␣(4),␣were detected by LC–MS in the cell suspension culture of A. sinensis elicited with crude extracts of M. flavolivens. Three hundred and seventy eight, 196 and 31 μg g⁻¹ DW of 2-(2-phenylethyl) chromones were obtained in the cell cultures induced by water extracts, 50 and 95% ethanol extracts of M. flavolivens, respectively. The results show that water-soluble materials in the crude extracts are the main components inducing the production of 2-(2-phenylethyl) chromones in the cell cultures.     

Synthesis of a 2-acetamido-5-amino-2,5-dideoxy- -xylopyranosyl derivative

2-Acetamido-5-amino-2,5-dideoxy- -xylopyranosyl hydrogensulfite (11) has been synthesized from benzyl 2-(benzyloxycarbonylamino)-2-deoxy-5,6-O-isopro-pylidene-β- -glucofuranoside (1). O-Deisopropylidenation of 1 gave the triol 2, which was converted, via oxidative cleavage at C-5-C-6 and subsequent reduction, into the related benzyl β- -xylofuranoside derivative (3). Catalytic reduction of benzyl 2-(benzyloxycarbonylamino)-2-deoxy-5-O-tosyl-β- -xylofuranoside, derived from 3 by selective tosylation, and subsequent N-acetylation, afforded benzyl 2-acetamido-2-deoxy-5-O-tosyl-β- -xylofuranoside, which was treated with sodium azide to give the corresponding 5-azido derivative (6). (Tetrahydropyran-2-yl)ation of the product formed by hydrolysis of 6 gave 2-acetamido-5-azido-2,5-dideoxy-1,3- di-O-(tetrahydropyran-2-yl)- -xylofuranose (9). Treatment of 2-acetamido-5-amino-2,5-dideoxy-1,3-di-O-(tetrahydropyran-2-yl)- -xylofuranose, derived from 9 by reduction, with sulfur dioxide in water gave 11. Hydrogenation of 6 and subsequent acetylation yielded 3-acetamido-4,5-diacetoxy-1-acetyl-xylo-piperidine. Evidence in support of the structures assigned to the new derivatives is presented.     

Microbial metabolism of 2-arylpropionic acids: Chiral inversion of ibuprofen and 2-phenylpropionic acid

The metabolism of (R,S)-ibuprofen has been investigated in 24 microbial cultures. Of these Cunninghamella elegans, Mucor hiemalis, and Verticillium lecanii catalyzed the oxidation of the drug to 2-[4-(2-hydroxy-2-methylpropyl)phenyl]propionic acid, a known mammalian metabolite. The extent of metabolism was greatest with V. lecanii, with some 47% of the substrate being consumed over a 7-day incubation period. Enantiomeric analysis indicated stereoselective metabolism of (R)-ibuprofen, the enantiomeric composition of the residual substrate being R/S = 0.25. Following a preparative scale incubation of (R,S)-ibuprofen with V. lecanii, in which the reaction was allowed to go to completion, the metabolite was found to be predominantly of the S-configuration (S/R = 2.1), suggesting that chiral inversion of either the drug and/or the metabolite had taken place. Analysis of extracts following incubation of (R,S)-, (R)-, and (S)-2-phenylpropionic acid with V. lecanii, for 21 days, indicated that chiral inversion of the (R)-enantiomer to its optical antipode had taken place. The results of these investigations indicate that microorganisms, in addition to mammals, are able to mediate the chiral inversion of 2-arylpropionic acids. This observation may have implications for the preparation of optically pure 2-arylpropionic acids. © 1993 Wiley-Liss, Inc.