Search

Thiamin diphosphate (ThDP) analogs have been designed and synthesized based on the ThDP binding site of the pyruvate dehydrogenase multienzyme complex E1 of Escherichia coli. This study investigated the effect of 66 novel ThDP analogs on rice bacterial brown stripe pathogen Acidovorax avenae subsp. avenae strain RS-1. Results indicated that three of the 66 ThDP analogs (designated as 20, 21 and 53) significantly inhibited the in vitro growth of strain RS-1. However, no obvious cell lysis and destruction was found for this rice pathogenic bacterium, which were supported by morphological evidence of transmission electron microscope. In contrast, the three ThDP analogs significantly reduced biofilm formation and the activity of the pyruvate dehydrogenase of strain RS-1. Furthermore, the differential expression of ThDP target gene and 20 secretion system related genes were revealed by using quantitative real-time PCR. Among these, the expressions of ThDP target gene and VgrG-5 under the treatment of ThDP 20 were strongly induced compared to the control, which indicated that the antibacterial mechanism of ThDP analogs may be mainly due to the changed expression of ThDP target gene and secretion system related genes rather than causing damage to cell membrane. Taken together, the application of synthesized ThDP analogs might be a tractable strategy to overcome the pathogen of rice bacterial brown stripe.

The redox state of carbon sources directly affected the ratio of NADH/NAD+ which was coupled to the hydrogen production by Bacillus sp. FS2011. The addition of the inhibitor of pyruvate dehydrogenase multi-enzyme complex (PDHc)E1 could regulate hydrogen production by FS2011 or pretreated compost in batch cultivation. With the addition of appropriate amount of inhibitor, hydrogen production via the NADH pathway was increased, leading to the higher overall hydrogen production. The maximum hydrogen yields of 307.6 ± 13.21 mL/g by FS2011 with the inhibitor of 80 ppm and 362.1 ± 10.1 mL/g by pretreated compost with the inhibitor of 60 ppm were observed, which were increased by 8.7% and 17.8% compared with the controls, respectively. Meanwhile the production of soluble metabolic byproducts such as butyrate, acetate and so on were decreased, resulting in reducing the difficulty of wastewater treatment.

Fifteen novel pyrazolo[3,4-b]-pyrido[4,3-d]-pyrimidine-4-ones (7a–o) were designed and have been successfully synthesized via tandem aza-Wittig and annulation reactions of the corresponding iminophosphorances 5, phenylisocyanate, and substituted phenols in 60–77% isolated yields. Their structures were clearly verified by infrared (IR), 1H NMR, electron impact–mass spectrometry (EI-MS), and elemental analysis. The results of a preliminary bioassay indicated that some compounds possess inhibition activities against the root of Brassica napus (rape) and Echinochloa crusgalli (barnyard grass) at a dosage of 100 mg/L and 10 mg/L.

In an attempt to discover novel compounds with high activity and low toxicity, a series of new O,O-dimethyl-α-(substituted phenoxyacetoxy)-2-pyridyl methyl phosphinates, 5a–5h, have been designed and synthesized by the reaction of substituted phenoxyacetic chloride with 1-hydroxy-2-pyridyl methyl phosphinate, The structures of all new compounds were characterized by elementary analysis, IR, 1H NMR, and MS spectroscopies. The results of preliminary bioassay indicate that most of the target compounds have excellent inhibitory activities on barnyard grass and rape.

Phosphorus-containing agrochemicals have made a major contribution to the advancement of agriculture in China. Current status about production and usages of organophosphorus agrochemicals in China is reviewed in this article. Development of new organophosphorus agrochemicals including insecticide, herbicide, and anti-TMV agent in recent years is introduced. Recent progress in research and development of α -(Substituted phenoxyacetoxy)alkylphosphonates is then described: α -(Substituted phenoxyacetoxy)alkylphosphonate II as a kind of potential agrochemicals was found on the basis of the study of a series of α -oxophosphonic acid derivatives I in our Lab. Some compounds II were demonstrated as effective inhibitors of pyruvate dehydrogenase complex from plant (in vitro) and showed notable herbicidal activity against broad-leaved weeds. Compound HW02 as a potential herbicide was evaluated and developed.

Eighteen novel 5-alkylamino-6-aryl-3-phenyl-2-thioxo-2,3-dihydrothiazolo[4,5-d]pyrimidin-7(6H)-ones 5a–r were designed and easily synthesized via a tandem aza-Wittig reaction. Treatment of iminophosphorane 2 with aromatic isocyanate gave carbodiimide 3, which reacted with fluoro-substituted alkylamines to provide the title compounds in 65–87% isolated yields using sodium ethoxide as catalyst. All compounds 5 were confirmed by IR, 1H NMR, MS and elemental analysis, and compound 5p was further analyzed by single-crystal X-ray diffraction. The preliminary bioassay indicated that some compounds showed significant inhibition activities against the root growth of rape and barnyard grass at a dosage of 100 mg/L.

Optically active α-substituted phenyloxyacetyloxy and aroyloxy phosphonates have been synthesized via catalytic asymmetric hydrogenation of the corresponding prochiral α,β-unsaturated phosphonates using Rh(I)/( R , R )-Me-DuPhos as the catalyst in methanol at 18 °C. The asymmetric hydrogenation reaction exhibits excellent enantioselectivity with enantiomeric excesses from 91 to 96%.

The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane I with aromatic isocyanates, reacted with secondary amines or ROH to give 5-dialkylamino or 5-alkoxy 7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in the presence of a catalytic amount of EtONa in a mixed solvent (CH 2 Cl 2 -ROH). Reactions of 2 with phenols in presence of catalytic potassium carbonate in MeCN gave 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in satisfactory yields.

A series of 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5 and its corresponding phosphonate monosalts 6 were synthesized as potential herbicide. The phosphonate monosalts can be prepared from 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5 , which were synthesized by the condensation of O , O -dimethyl-1-hydroxyalkylphosphonates with dichlorophenoxyacetic chloride. This method provides a simple and efficient procedure for the synthesis of phosphonate derivatives containing sensitive groups to acid, base or water such as carboxylate ester bond; and the herbicidal activity of title compounds was evaluated in a set of experiments in greenhouse. Most of the compounds exhibited notable herbicidal activity.

A series of α‐(2,4‐dichlorophenoxyacetoxy)aryl methyl phosphonate monosodium salts 6 were synthesized by the reaction of the intermediate 5 with sodium iodide under moderate condition. This method was applied to the synthesis of novel phosphonate derivatives containing sensitive groups such as carboxylic ester to acid, base, or water.

Some α-OxoPhosphonate monolithium salts were synthesized by a facile one-step procedure. In this way, α-(2,4-dichlorophenoxyacetoxy)alkyl phosphonic acid dimethyl esters 5 can be transformed into the corresponding phosophonate monolithium salts 6 without influence on the carboxylic ester group under mild conditions.

Synthesis and cytotoxicity of 11 4-methylene pyrido[4,3-d]pyrimidines 5a-k were described. Cytotoxicity assay results showed that some compounds had much stronger antitumor activity than Fluorouracil against KB cell lines. The most active compound 5i exhibited high potency against KB, CNE2, MGC-803 cell lines with IC(50) values of 0.48, 0.15, 0.59 μM, respectively. The preliminary structure-activity relationships indicated that the introduction of benzyl groups bearing electron-donating function groups is favorable for the activity.

The carbodiimides 4, obtained from aza-Wittig reactions of iminophosphorane 3 with aromatic isocyanates, reacted with amines in the presence of a catalytic amount of RO−Na+ to give the 1,2,9-trisubstituted 1,9-dihydro-6H-purin-6-ones 6 in good yields. Compound 6 exhibited cytotoxicity against various cancer cells. For example, compounds 6b showed the best inhibition activities against KB, HepG2 and OVCAR3 with IC50 9.5, 20.4 and 10.0 μM.

Thirteen novel pyrazolo[3″,4″:2,3]pyrido[4,5-d]pyrimidin-4-ones 7a–m were synthesised via tandem aza-Wittig and annulation reactions of the corresponding iminophosphoranes 5, phenylisocyanate, and substituted amine in 56–86% yields. Their structures were verified by IR, 1H NMR, EI-MS spectroscopy and elemental analysis. Preliminary bioassay indicated that some compounds possess inhibition activity against Brassica napus (rape) and Echinochloa crusgalli (barnyard grass).

In the title compound, C15H17N5O2, all ring atoms in the triazolopyrimidinone system are almost coplanar. The packing of the molecules in the crystal structure is mainly due to intermolecular C—H...O hydrogen-bonding interactions.

Novel pyrimidoquinolone derivatives (VI),(XI),(XII), and (XIII), substituted at positions 2 and 3, are synthesized by using three synthetic routes and evaluated for their antiproliferative activities against a panel of six human cancer cell lines.

A series of pyrimido[5,4- c ]quinoline-4-(3 H )-one derivatives variously substituted at positions 2 and 3 were synthesized and evaluated for their in vitro antiproliferative activities against a panel of six human cancer cell lines. Biological evaluation revealed that the vast majority of derivatives exhibited moderate tumor growth inhibitory activities. In particular, compound 7e showed effective anti-tumor activity with broad-spectrum toward numerous cell lines and the most active member in this study. This derivative displaying significant activity against KB (IC 50 : 4.9 μM), CNE2 (IC 50 : 13.8 μM), MGC-803 (IC 50 : 4.8 μM), GLC-82 (IC 50 : 7.88 μM), MDA-MB-453 (IC 50 : 18.2 μM) and MCF-7 (IC 50 : 10.1 μM) cell lines could be considered as the most promising and useful template for future development to obtain more potent anti-tumor agent(s).

Garcinia xanthochymus has been widely used in traditional Chinese medicine for expelling worms and removing food toxins. Bioassay-guided fractionation of an EtOAc-soluble extract of G. xanthochymus stem bark led to the isolation of six new xanthones. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques. Free-radical-scavenging activities of the isolated compounds were elucidated through DPPH method. Most of the isolated compounds showed considerable free radical scavenging activity on DPPH assay. Compound 1 exhibited effective antioxidant scavenging activity against DPPH radical with an IC50 value of 19.64 μM, and compound 6 showed the lowest activity among all the tested molecules, with an IC50 value of 66.88 μM. These findings support the notion that the plant genus Garcinia is a good source of bioactive compounds.

Fifteen novel pyrazolo[3,4-b]-pyrido[4,3-d]-pyrimidine-4-ones (7a–o) were designed and have been successfully synthesized via tandem aza-Wittig and annulation reactions of the corresponding iminophosphorances 5, phenylisocyanate, and substituted phenols in 60–77% isolated yields. Their structures were clearly verified by infrared (IR), 1H NMR, electron impact–mass spectrometry (EI-MS), and elemental analysis. The results of a preliminary bioassay indicated that some compounds possess inhibition activities against the root of Brassica napus (rape) and Echinochloa crusgalli (barnyard grass) at a dosage of 100 mg/L and 10 mg/L.

The carbodiimides 4, obtained from aza-Wittig reactions of iminophosphorane 3 with aromatic isocyanates, reacted with amines in the presence of a catalytic amount of RO−Na+ to give the 1,2,9-trisubstituted 1,9-dihydro-6H-purin-6-ones 6 in good yields. Compound 6 exhibited cytotoxicity against various cancer cells. For example, compounds 6b showed the best inhibition activities against KB, HepG2 and OVCAR3 with IC50 9.5, 20.4 and 10.0 μM.

Thirteen novel pyrazolo[3",4":2,3]pyrido[4,5-d]pyrimidin-4-ones 7a-m were synthesised via tandem aza-Wittig and annulation reactions of the corresponding iminophosphoranes 5, phenylisocyanate, and substituted amine in 56-86% yields. Their structures were verified by IR, 1 H NMR, El-MS spectroscopy and elemental analysis. Preliminary bioassay indicated that some compounds possess inhibition activity against Brassica napus (rape) and Echinochloa crusgalli (barnyard grass).

チアザホスホリジン類は, アミノアルコールより硫酸エステルを経て得た2-メルカプトチアゾリンの塩酸触媒加水分解により合成したアミノチオールと, チオリン酸ジクロリドより合成した. チアザホスホリジン (SP) は, 局所施用法でイエバエに対し, オキサアザホスホリジン (OP) より高い殺虫活性を示した. OP, SPともに, メトキシ体はエトキシ体よりも活性が高く, よりかさ高い疎水性置換基を4位に持つ誘導体がより高い殺虫活性を示したが, SPにおいては, かさ高い疎水性置換基の導入による殺虫活性の増加はOPの場合よりも著しくなかった. OP, SPともに, ゴキブリ神経アデニレートシクラーゼを活性化しなかったが, オクトパミンに対して拮抗作用を示した.

In the crystal structure of the title compound, C(14)H(14)F(3)O(7)P, the central chain, which connects the phosphate bicyclic system and the benzene ring, is made up of an approximately planar C-C(O)-O-C(H(2)) fragment and a C(H(2))-O-C(Ph) link; the mean planes make a dihedral angle of 75.9 (2)°. The F atoms are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.

The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane I with aromatic isocyanates, reacted with secondary amines or ROH to give 5-dialkylamino or 5-alkoxy 7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in the presence of a catalytic amount of EtONa in a mixed solvent (CH 2 Cl 2 -ROH). Reactions of 2 with phenols in presence of catalytic potassium carbonate in MeCN gave 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in satisfactory yields.

The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with primary amine RNH2 (R ≠ H, Me) to produce isolable guanidine intermediates 3, w...

A series of sodium methyl α-(substituted phenoxy acetoxy)-alkyl phosphinates were synthesized under mild condition by a simple efficient procedure.