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1.
Takayuki Oritani Sachio Kudo Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(3):757-760
Asymmetric hydrolysis of acetate (10) of (±)-t-2,t-4-dimethyl-r-l-cyclohexanol with Bacillus subtilis var. niger gave (?)-(lS,2S,4S)-2,4-dimethyl-l-cyclohexanol (6a) and (+)-(1R,2R,4R)-acetate (10b) with high optical purities. Optically pure (?) and (+)-alcohols (6a and 6b) were prepared via corresponding 3,5-dinitrobenzoates. Oxidation of alcohols (6a and 6b) with chromic acid gave optically pure (?)-(2S,4S) and (+)-(2R,4R)-2,4-dimethyl-l-cyclohexanones (2a and 2b), respectively. 相似文献
2.
Both (3R)- and (3S)-enantiomers of the chiral green tea flavor compound 3-hydroxy-3-methylnonane-2,4-dione were synthesized by the combined use of acetylacetoin synthase and acetylacetoin reductase from Bacillus licheniformis. The first enzyme was utilized to catalyze the homo-coupling of 2,3-octanedione and obtain the enantioenriched (3R)-3-hydroxy-3-methylnonane-2,4-dione (ee 44%). The NADH-dependent acetylacetoin reductase was then employed for the diastereoselective (de > 95%) C2 carbonyl reduction of the sole (3R)-enantiomer of the above 2,4-dione, thus affording the syn diol (2S,3R)-2,3-dihydroxy-3-methylnonan-4-one in enantiomerically pure form. While this step allowed for the recovery of unreacted, optically pure (3S)-3-hydroxy-3-methylnonae-2,4-dione, the corresponding (3R)-enantiomer was obtained by subsequent TEMPO-mediated oxidation of the syn diol intermediate. Moreover, using the title compounds as analytical standards, predominance of the (3R) enantiomer in the natural flavor compound was finally demonstrated by chiral GC–MS analysis. 相似文献
3.
Hongkyu Yoon Sabine Leibeling Changyong Zhang Roland H. Müller Charles J. Werth Julie L. Zilles 《Biodegradation》2014,25(4):595-604
Delftia acidovorans MC1071 can productively degrade R-2-(2,4-dichlorophenoxy)propionate (R-2,4-DP) but not 2,4-dichlorophenoxyacetate (2,4-D) herbicides. This work demonstrates adaptation of MC1071 to degrade 2,4-D in a model two-dimensional porous medium (referred to here as a micromodel). Adaptation for 2,4-D degradation in the 2 cm-long micromodel occurred within 35 days of exposure to 2,4-D, as documented by substrate removal. The amount of 2,4-D degradation in the adapted cultures in two replicate micromodels (~10 and 20 % over 142 days) was higher than a theoretical maximum (4 %) predicted using published numerical simulation methods, assuming instantaneous biodegradation and a transverse dispersion coefficient obtained for the same pore structure without biomass present. This suggests that the presence of biomass enhances substrate mixing. Additional evidence for adaptation was provided by operation without R-2,4-DP, where degradation of 2,4-D slowly decreased over 20 days, but was restored almost immediately when R-2,4-DP was again provided. Compared to suspended growth systems, the micromodel system retained the ability to degrade 2,4-D longer in the absence of R-2,4-DP, suggesting slower responses and greater resilience to fluctuations in substrates might be expected in the soil environment than in a chemostat. 相似文献
4.
Sachio Kudo Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(10):2919-2923
(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. 相似文献
5.
Sachio Kudo Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(11):2739-2743
Such (+)- and (?)-cis-cycloheximide isomers as isocyclohcximide (1a, 1b), α-epiisocycloheximide (2a, 2b) and neocycloheximide (3a, 3b) were synthesized by aldol condensation of (?)-(2R, 4R)- and (+)-(2S, 4S)-cis-2,4-dimethyl-1-cyclohexanone (5a, 5b). obtained by microbial resolution, with 4-(2-oxoethyl)-2,6-piperidinedione (7). The absolute configuration of the (?)-cis-ketone 5a was confirmed by chemical correlation with natural (2S, 4S, 6S, αR)-cycloheximide (4). The newly synthesized isomer, (?)-α-epiisocycloheximide (2b), showed strong antimicrobial activity against S. cerevisiae andP. oryzae close to that of natural cycloheximide (4). 相似文献
6.
Isolation and characterization of a 2-(2,4-dichlorophenoxy) propionic acid-degrading soil bacterium 总被引:1,自引:0,他引:1
Manfred Horvath Günther Ditzelmüller Michael Loidl Franz Streichsbier 《Applied microbiology and biotechnology》1990,33(2):213-216
Summary The 2-(2,4-dichlorphenoxy)propionic acid (2,4-DP)-degrading bacterial strain MH was isolated after numerous subcultivations of a mixed culture obtained by soil-column enrichment and finally identified as Flavobacterium sp. Growth of this strain was supported by 2,4-DP (maximum specific growth rate 0.2 h–1) as well as by 2,4-dichlorophenoxyacetic acid (2,4-D), 4(2,4-dichlorophenoxy)butyric acid (2,4-DB), and 2-(4-chloro-2-methyphenoxy)propionic acid (MCPP) as sole sources of carbon and energy under aerobic conditions. 2,4-DP-Grown cells (108) of strain MH degraded 2,4-dichlorophenoxyalkanoic acids, 2,4-dichlorophenol (2,4-DCP), and 4-chlorophenol at rates in the range of 30 nmol/h. Preliminary investigations indicate that cleavage of 2,4-DP results in 2,4-DCP, which is further mineralized via ortho-hydroxylation and ortho-cleavage of the resulting 3,5-dichlorocatechol.
Offprint requests to: F. Streichsbier 相似文献
7.
Zificsak CA Theroff JP Aimone LD Angeles TS Albom MS Cheng M Mesaros EF Ott GR Quail MR Underiner TL Wan W Dorsey BD 《Bioorganic & medicinal chemistry letters》2011,21(13):3877-3880
The incorporation of R,R-1,2-diaminocyclohexane at C4 in a series of 2,4-diaminopyrimidines led to a number of ALK inhibitors in which optimized activity was achieved by conversion of the 2-amino group into a methanesulfonamide. Tumor growth inhibition was observed when an orally bioavailable analog was evaluated in a Karpas-299 tumor xenograft mouse model. 相似文献
8.
Transformation of 2,4-dinitrotoluene (2,4-DNT) by Alcaligenes JS867 undervarying degrees of oxygen limitation was examined. Complete 2,4-DNT removalwas observed under oxygen excess with near stoichiometric release (83%) of nitrite.Average kinetic parameters were estimated based on a dual-Monod biokinetic modelwith 2,4-DNT and O2 as growth limiting substrates. The negative impact of nitrite accumulation on the reaction rate was adequately described by inclusion of a noncompetitive inhibition term for NO2
-. Under aerobic conditions, max, KsDNT, andKiNO were 0.058(0.004) hr-1, 3.3(±1.3) mg 2,4-DNT/L, and 1.2(±pm0.2) hr-1, respectively. At increasing oxygen limitation, rates of 2,4-DNT disappearance and nitrite production decreased and incomplete removal of 2,4-DNT commenced. JS867 was able to use NO2
- as a terminal electron acceptor whengrown on glucose or succinate under anaerobic conditions. However, during growthon 2,4-DNT and under O2-limited conditions, JS867 did not use released nitrite as electron acceptor. The nearly constant molar ratios of DNT removed over NO2
- released under various degrees of oxygen limitation suggested that oxygenolytic denitration pathways continued. No evidence of nitroreduction was obtained under the examined oligotrophic conditions. JS867 displayed a high affinity for oxygen consumption with KSO2 value of 0.285(±0.198) mg O2/L. Our results indicate thatunder oligotrophic conditions with 2,4-DNT as dominant carbon source, oxygen availability and nitrite accumulation may limit 2,4-DNT biomineralization, but the accumulation of reduced 2,4-DNT transformation products will be small. 相似文献
9.
2,4-Dimethylphenoxyacetic acid and 2,4-dimethylphenol are not growth substrates for Alcaligenes eutrophus JMP 134 although being cooxidized by 2,4-dichlorophenoxyacetate grown cells. None of the relevant catabolic pathways were induced by the dimethylphenoxyacetate. 3,5-Dimethylcatechol is not subject to metacleavage. The alternative ortho-eleavage is also unproductive and gives rise to (+)-4-carboxymethyl-2,4-dimethylbut-2-en-4-olide as a dead-end metabolite. High yields of this metabolite were obtained with the mutant Alcaligenes eutrophys JMP 134-1 which constitutively expresses the genes of 2,4-dichlorophenoxyacetic acid metabolism. 相似文献
10.
S. P. Ozheredov A. I. Yemets V. M. Brytsun I. P. Ozheredova M. O. Lozynsky Ya. B. Blume 《Cytology and Genetics》2009,43(5):297-304
Screening of antimitotic activity and phytotoxicity of new 2,4- and 2,6-dinitroaniline derivates has been performed using
the Allium-test. All substances that are derivatives of 2,4-dinitroanilines, 2,6-dinitro-(4-fluoromethyl)-aniline, and of (methylsulfonyl)
nitrobenzol, proved to change the value of the mitotic index, cause cytogenetic disorders, and have a phytotoxic effect on
the roots of Allium cepa seedlings. The results obtained suggest that N-(2,4-dinitrophenyl)-orto-aminobenzoic acid, N, N, -diethyl-2,6-dinitro-4-(trifluoromethyl)-aniline, and 1-methylsulfonyl-3-nitrobenzol are potential herbicides; further studying
of their effects is proposed. 相似文献
11.
《Bioscience, biotechnology, and biochemistry》2013,77(11):1728-1731
(2E,4E)-geometry was assigned to 1233A [(7R,2?R,3?R)-11-[3?-(hydroxymethyl)-4?-oxo-2?-oxetanoyl]-3,5,7-trimethyl-2,4-undecadienoic acid (1a)], an inhibitor of cholesterol biosynthesis. Both the 1H- and 13C-NMR spectra of 1a and methyl ester 1b were compared with those of the four geometrical isomers of methyl 3,5-dimethyl-2,4-heptadienoate (2). NOE experiments on 1b revealed the presence of a remarkable NOE between the proton at C-2 and those of the C-17 methyl group. Similar NOE was also observed with (2E,4E)-2. This fact suggests the predominant existence of stable s-cis-rotamers at the single bond between C-3 and C-4 of 1b and of (2E,4E)-2. Some MM2 calculations were attempted to show the presence of two types of stable conformers in the case of the 3,5-dimethyl-2,4-dienoate system. 相似文献
12.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1526-1529
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. 相似文献
13.
Sabine Leibeling Marten B. Maeß Florian Centler Sabine Kleinsteuber Martin von Bergen Martin Thullner Hauke Harms Roland H. Müller 《Engineering in Life Science》2013,13(3):278-291
Microbial activities and the versatility gained through adaptation to xenobiotic compounds are the main biological forces to counteract environmental pollution. The current results present a new adaptive mechanism that is mediated through posttranslational modifications. Strains of Delftia acidovorans incapable of growing autochthonously on 2,4‐dichlorophenoxyacetate (2,4‐D) were cultivated in a chemostat on 2,4‐D in the presence of (R)‐2‐(2,4‐dichlorophenoxy)propionate. Long‐term cultivation led to enhanced 2,4‐D degradation, as demonstrated by improved values of the Michaelis–Menten constant Km for 2,4‐D and the catalytic efficiency kcat/Km of the initial degradative key enzyme (R)‐2‐(2,4‐dichlorophenoxy)propionate/α‐ketoglutarate‐dependent dioxygenases (RdpA). Analyses of the rdpA gene did not reveal any mutations, indicating a nongenetic mechanism of adaptation. 2‐DE of enzyme preparations, however, showed a series of RdpA forms varying in their pI. During adaptation increased numbers of RdpA variants were observed. Subsequent immunoassays of the RdpA variants showed a specific reaction with 2,4‐dinitrophenylhydrazine (DNPH), characteristic of carbonylation modifications. Together these results indicate that posttranslational carbonylation modified the substrate specificity of RdpA. A model was implemented explaining the segregation of clones with improved degradative activity within the chemostat. The process described is capable of quickly responding to environmental conditions by reversibly adapting the degradative potential to various phenoxyalkanoate herbicides. 相似文献
14.
Sergent D Wang Q Sasaki NA Ouazzani J 《Bioorganic & medicinal chemistry letters》2008,18(15):4332-4335
The first synthesis of an optically pure (2R,3R,4S)-hydantoin 2, analogue of (2S,3R,4S)-4-hydroxyisoleucine, was achieved in two steps in un-optimized 35% overall yield from previously reported aldehyde synthon 1. (2R,3R,4S)-Hydantoin is stable at acidic pH. This solves the major drawback of (2S,3R,4S)-4-hydroxyisoleucine that easily cyclizes into inactive lactone. Furthermore, (2R,3R,4S)-hydantoin stimulates the insulin secretion by 150% at 25 μM compared with 4-hydroxyisoleucine and insulin secretagogue drug repaglinide. In view of its stability and biological activity, (2R,3R,4S)-hydantoin represents a good candidate for type-2 diabetes management and control. 相似文献
15.
Enantioselective Uptake and Degradation of the Chiral Herbicide Dichlorprop [(RS)-2-(2,4-Dichlorophenoxy)propanoic acid] by Sphingomonas herbicidovorans MH
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Christian Zipper Monika Bunk Alexander J. B. Zehnder Hans-Peter E. Kohler 《Journal of bacteriology》1998,180(13):3368-3374
Sphingomonas herbicidovorans MH was able to completely degrade both enantiomers of the chiral herbicide dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid], with preferential degradation of the (S) enantiomer over the (R) enantiomer. These results are in agreement with the recently reported enantioselective degradation of mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propanoic acid] by this bacterium (C. Zipper, K. Nickel, W. Angst, and H.-P. E. Kohler, Appl. Environ. Microbiol. 62:4318–4322, 1996). Uptake of (R)-dichlorprop, (S)-dichlorprop, and 2,4-D (2,4-dichlorophenoxyacetic acid) was inducible. Initial uptake rates of cells grown on the respective substrate showed substrate saturation kinetics with apparent affinity constants (Kt) of 108, 93, and 117 μM and maximal velocities (Vmax) of 19, 10, and 21 nmol min−1 mg of protein−1 for (R)-dichlorprop, (S)-dichlorprop, and 2,4-D, respectively. Transport of (R)-dichlorprop, (S)-dichlorprop, and 2,4-D was completely inhibited by various uncouplers and by nigericin but was only marginally inhibited by valinomycin and by the ATPase inhibitor N,N′-dicyclohexylcarbodiimine. Experiments on the substrate specificity of the putative transport systems revealed that (R)-dichlorprop uptake was inhibited by (R)-mecoprop but not by (S)-mecoprop, (S)-dichlorprop, or 2,4-D. On the other hand, the (S)-dichlorprop transport was inhibited by (S)-mecoprop but not by (R)-mecoprop, (R)-dichlorprop, or 2,4-D. These results provide evidence that the first step in the degradation of dichlorprop, mecoprop, and 2,4-D by S. herbicidovorans is active transport and that three inducible, proton gradient-driven uptake systems exist: one for (R)-dichlorprop and (R)-mecoprop, another for (S)-dichlorprop and (S)-mecoprop, and a third for 2,4-D. 相似文献
16.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2384-2389
Bacterial strain B-009, capable of using racemic 1,2-propanediol (PD), was identified as a rapid-growing member of the genus Mycobacterium. The strain is phylogenetically related to M. gilvum, but has slightly different physiological characteristics. An NAD+-dependent enantioselective alcohol dehydrogenase, which acts on R-PD, was purified from the strain. The enzyme was a homodimer of a peptide coded by a 1047-bp gene (mbd1). A highly conserved sequence for medium-chain dehydrogenase/reductases with a preference for secondary alcohols was found in the gene. Hydroxyacetone was produced from R-PD by an enzymatic reaction, indicating that position 2 of the substrate was oxidized. The enzyme activity was highest for (2R,3R)-2,3-butanediol (R,R-BD), enabling the enzyme to be identified as (2R,3R)-2,3-butanediol dehydrogenase (R,R-BD-DH). A homology search revealed M. gilvum, M. vanbaalenii, and M. semegmatis to have ORFs similar to mbd1, suggesting the widespread distribution of genes encoding R,R-BD-DH among mycobacterial strains. 相似文献
17.
Shiho Sato Ferry Ferdiansyah Sofian Wataru Suehiro Desi Harneti Rani Maharani Unang Supratman Fajar Fauzi Abdullah Supriatno Salam Takuya Koseki Yoshihito Shiono 《化学与生物多样性》2021,18(3):e2000928
Nine new β-resorcylic acid derivatives, (15S)-de-O-methyllasiodiplodin ( 1 ), (13S,15S)-13-hydroxy-de-O-methyllasiodiplodin ( 2 ), (14S,15S)-14-hydroxy-de-O-methyllasiodiplodin ( 3 ), (13R,14S,15S)-13,14-dihydroxy-de-O-methyllasiodiplodin ( 4 ), ethyl (S)-2,4-dihydroxy-6-(8-hydroxynonyl)benzoate ( 5 ), ethyl 2,4-dihydroxy-6-(8-hydroxyheptyl)benzoate ( 6 ), ethyl 2,4-dihydroxy-6-(4-methoxycarbonylbutyl)benzoate ( 7 ), 3-(2-ethoxycarbonyl-3,5-dihydroxyphenyl)propionic acid ( 8 ), and isobutyl (S)-2,4-dihydroxy-6-(8-hydroxynonyl)benzoate ( 9 ), together with a known ethyl 2,4-dihydroxy-6-(8-oxononyl)benzoate ( 10 ) were obtained from Lasiodiplodia theobromae GC-22. The structures of these compounds were elucidated by extensive spectroscopic analyses. Compounds 1 , 3 , and 6 showed growth inhibitory effects against Digitaria ciliaris. Conversely, treatment with compounds 5 , 6 , 7 , 9 , and 10 stimulated elongation activity toward the root of Lactuca sativa. These data expand the repertoire of new β-resorcylic acid derivatives that may function as lead compounds in the synthesis of new agrochemical agents. 相似文献
18.
Both enantiomers of 2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylic acid 2 and 2,4-dimethyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylic acid 3 were prepared via resolution of the corresponding racemic carboxylic acids with (R)- and (S)-1-phenylethylamine, respectively. Absolute configuration of (−)-(R)-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylic acid was determined by X-ray crystallography. Curtius rearrangement of acyl azides prepared from enantiomers of these heterocyclic carboxylic acids carried out in benzyl alcohol afforded enantiomers of the corresponding benzyl carbamates, which upon hydrogenolysis gave racemic 2-amino-2-methyl-3,4-dihydro-2H-1,4-benzoxazin-3-one 4 and 2-amino-2,4-dimethyl-3,4-dihydro-2H-1,4h-benzoxazin-3-one 5. Chirality 10:791–799, 1998. © 1998 Wiley-Liss, Inc. 相似文献
19.
Sachio Kudo Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(9):2315-2319
Optically active tiraras-cycloheximide isomers such as cycloheximide [(2S,4S,6R,αR)-form (1)], naramycin B[(25,4S,6RαR)-form(4)], and new stereoisomers (2S,4S,6S,αS)-form (8) and (2S,4S,6R,αS)-from (9) were synthesized by an aldol condensation of trans-2,4-dimethyl-l-cyclohexanone (5b), with 4-(2-oxoethyl)-2,6-piperidinedione(6). The antimicrobial activity of trans- cycloheximide isomers (1, 4, 8, and 9) was examined against S. cerevisiae and P. oryzae. The stereoisomers 1 and 4 exhibited marked antimicrobial activity against both microorganisms as compared with their C- α-epimers 8 and 9. 相似文献
20.
Virginia L. Gemini Alfredo Gallego Valeria Tripodi Daniel Corach Estela I. Planes Sonia E. Korol 《International biodeterioration & biodegradation》2007,60(4):226-230
A bacterial strain was isolated from a river sediment in Buenos Aires, Argentina, owing to its ability to utilize 2,4-dinitrophenol (2,4-DNP) as the sole carbon, nitrogen and energy source. The strain was identified as Rhodococcus opacus on the basis of its 16S rRNA gene sequence. R. opacus degrades aerobically 0.27 and 0.54 mM within 22 and 28 h, respectively, and releases the nitro groups from 2,4-DNP as nitrites. Aerobic biodegradation processes were performed using a 2-l volume microfermentor at with agitation (200 rpm), and were evaluated by spectrophotometry, high performance liquid chromatography (HPLC) and microbial growth. The absence of 2,4-DNP transformation products was also confirmed by gas chromatography mass spectrometry (GC–MS). As the nitrite released during 2,4-DNP degradation is in addition an environmental toxic agent it was removed by denitrification in an anoxic process. Detoxification was assessed by using luminescent bacteria, algae and seeds toxicity tests. Toxicity was not detected after combining both the aerobic and anoxic processes. 相似文献