Methicillin-resistant (MRSA) is a worldwide health threat and has already tormented humanity during its long history, creating an urgent need for the development of new classes of antibacterial agents. In this study, twenty-one novel sulfonylurea derivatives containing phenyl-5-vinyl and pyrimidinyl-4-aryl moieties were designed and synthesized, among which, nine compounds exhibited inhibitory potencies against Gram-positive bacterial strains: MRSA (Chaoyang clinical isolates), ATCC6538, vancomycin-resistant -309 (VRE-309), and ATCC 6633. Especially, and demonstrated inhibitory activities against the four bacterial strains with minimum inhibitory concentrations (MICs) of 0.
View Article and Find Full Text PDFBased on the previous finding that a substitution at 5-position of the benzene ring is favorable to enhance the degradation rates of sulfonylurea herbicides, a total of 16 novel 2,5-disubsituted sulfonylurea compounds were chemically synthesized and fully characterized by means of H NMR, C NMR, HRMS and X-ray diffraction. By using HPLC analysis, the degradation behavior of M03, a compound belonging to this family, was studied and confirmed that chlorsulfuron itself is not a degraded product of the 2,5-disubstituted sulfonylureas. Inhibition constants against plant acetohydroxyacid synthase (AHAS) were determined for selected compounds, among which SU3 showed seven times stronger activity against the mutant W574L enzyme than chlorsulfuron.
View Article and Find Full Text PDFBackground: Chlorsulfuron, metsulfuron-methyl and ethametsulfuron can damage sensitive crops in rotation pattern as a result of their long persistence in soil. To explore novel sulfonylurea (SU) herbicides with favorable soil degradation rates, four series of SUs were synthesized through a structure-based drug design (SBDD) strategy.
Results: The target compounds, especially Ia, Id and Ie, exhibited prospective herbicidal activity against dicotyledon oil seed rape (Brassica campestris), amaranth (Amaranthus retroflexus), monocotyledon barnyard grass (Echinochloa crusgalli) and crab grass (Digitaria sanguinalis) at a concentration of 15 a.
Sulfonylurea herbicides can lead to serious weed resistance due to their long degradation times and large-scale applications. This is especially true for chlorsulfuron, a widely used acetolactate synthase inhibitor used around the world. Its persistence in soil often affects the growth of crop seedlings in the following crop rotation, and leads to serious environmental pollution all over the world.
View Article and Find Full Text PDFChlrosulfuron, a classical sulfonylurea herbicide that exhibits good safety for wheat but causes a certain degree of damage to subsequent corn in a wheat-corn rotation mode, has been suspended field application in China since 2014. Our previous study found that diethylamino-substituted chlorsulfuron derivatives accelerated the degradation rate in soil. In order to obtain sulfonylurea herbicides with good crop safety for both wheat and corn, while maintaining high herbicidal activities, a series of pyrimidine- and triazine-based diethylamino-substituted chlorsulfuron derivatives (-) were systematically evaluated.
View Article and Find Full Text PDFSulfonylurea herbicides are widely used as acetolactate synthase (ALS) inhibitors due to their super-efficient activity. However, some sulfonylurea herbicides show toxicity under crop rotation due to their long degradation time, for example, chlorsulfuron. Our research goal is to obtain chlorsulfuron-derived herbicides with controllable degradation time, good crop safety and high herbicidal activities.
View Article and Find Full Text PDFOwing to the lengthy residual problems associated with chlorsulfuron, metsulfuron-methyl, and ethametsulfuron, which prevents them from being used in the "annual multi-crop planting system", the application of these sulfonylurea herbicides (SU) has regrettably been terminated in China since 2014. In this field, we were the first to discover that the 5 position of the benzene ring in chlorsulfuron is a key point for influencing its degradation rate and the amino moiety at this position showed faster degradation rates and maintained their original potent bioactivity. In this study, we further elaborated on -methylamido and dialkylamino substituents at the same position in chlorsulfuron to obtain 18 novel structures as M and N series.
View Article and Find Full Text PDFBackground And Objective: Insulin resistance is well known to exhibit essential effects on the progression of diabetes mellitus (DM). Guava leaf was also reported to exhibit anti-diabetic effects including decreasing blood glucose. Therefore, this present study aims to explore the role guava leaf extract (GLE) plays in insulin resistance and its mechanism of action via the PI3K/Akt signaling pathway.
View Article and Find Full Text PDFChlorsulfuron has been applied in wheat fields as a recognized herbicide worldwide, yet it was officially banned in China since 2014 for its soil persistence problem. On the basis of our previous research that 5-dimethylamino distinctively accelerated degradation rate in soils, a modified amino moiety () and monosubstituted amino group () were introduced onto the fifth position of the benzene ring in sulfonylurea structures, as well as heterocyclic amino substituents () to seek a suitable soil degradation rate during such an in situ crop rotation system. Referring to the biological data and AHAS inhibition and AHAS docking results, they turned out to be AHAS inhibitors with high potent herbicidal activities.
View Article and Find Full Text PDFBackground: N-Pyridylpyrazole derivatives have received continuous attention in agrochemical research during the last decade owing to their remarkable insecticidal or fungicidal potentials. To look for novel heterocyclic agrochemicals for increasing production of agriculture, a series of novel α-aminophosphonate derivatives containing N-pyridylpyrazole moiety were synthesized.
Results: The structures of the title compounds were confirmed via melting point, IR, H NMR, C NMR, P NMR, HRMS and elemental analysis.
Anthranilic diamide insecticide could control lepidopteran pests by selectively binding and activating insect ryanodine receptors (RyRs), and the unique mode of action is different from other conventional insecticides. In order to discover new anthranilic diamide insecticide as ryanodine receptors activators, a series of 11 novel anthranilic diamides derivatives (Ia-k) were synthesized and confirmed by melting point, H NMR, C NMR and elemental analyses. The preliminary bioactivity revealed that most title compounds showed moderate to remarkable activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella).
View Article and Find Full Text PDFJavanicunines A-B and 9-deoxy-PF1233s A-B belong to a family of natural diketomorpholines with a unique isopropenyl group at C-10b or C-5a and a hydroxyl group at C-11a or C-10b. We herein reported the first total synthesis of javanicunines A-B and 9-deoxy-PF1233s A-B. Pivotal features of the synthesis included a nucleophilic substitution reaction, followed by a Davis' oxaziridine oxidation to assemble javanicunines A-B, and a chemoselective and stereoselective oxidation with Murray's reagent to install the requisite C-10b hydroxyl group in 9-deoxy-PF1233s A-B.
View Article and Find Full Text PDFBackground: Anthranilic diamide insecticides control lepidopteran pests through selectively binding and activating insect ryanodine receptors. In order to search for potential insecticides targeting the ryanodine receptors, a series of anthranilic diamide analogs including trifluoromethyl, nitro, or chloro groups were designed and synthesized by the principle of bioisosterism and structural optimization.
Results: Insecticidal data indicated that some compounds displayed good activity against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella).
A series of novel anthranilic diamides derivatives (7a-s) containing halogen, trifluoromethyl group and cyano group were designed, synthesized, and characterized by melting point, H NMR, C NMR and elemental analyses. The bioactivity revealed that most of them showed moderate to excellent activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella). Above all, the larvicidal activity of 7o against oriental armyworm was 100% and 40% at 0.
View Article and Find Full Text PDFConcise total syntheses of the natural phytoalexins 2-hydroxy-8-(4-hydroxyphenyl)phenalen-1-one (1), 2-hydroxy-8-(3,4-dihydroxyphenyl)phenalen-1-one (2), and hydroxyanigorufone (4), together with regioisomer 3 are accomplished in 11 or 12 steps. The synthetic strategy features a Friedel-Crafts acylation to construct the 1H-phenalen-1-one tricyclic core followed by a Suzuki cross-coupling to obtain the target compounds.
View Article and Find Full Text PDFA series of new 3-substitutedphenyl-4-substitutedbenzylideneamino-1,2,4-triazole Mannich bases and bis-Mannich bases were synthesized through Mannich reaction with high yields. Their structures were confirmed by means of IR, H NMR, C NMR and elemental analysis. The preliminary bioassay indicated that compounds 7g, 7h and 7l exhibited potent in vitro inhibitory activities against ketol-acid reductoisomerase (KARI) with K value of (0.
View Article and Find Full Text PDFBackground: In recent years, pyridylpyrazole derivatives, such as pyridylpyrazole-containing anthranilic diamide have attracted much attention by virtue of their useful insecticidal properties and unique action mode. Moreover, some pyridylpyrazole-containing compounds have also been found to possess significant fungicidal activities. With the aim of discovering new bioactive agrochemicals for crop protection, a series of poly-heterocyclic compounds containing pyridylpyrazole and aziridine, or β-lactam, or thiazolinone moieties were synthesized.
View Article and Find Full Text PDFThe degradation issue of sulfonylurea (SU) has become one of the biggest challenges that hamper the development and application of this class of herbicides, especially in the alkaline soils of northern China. On the basis of the previous discovery that some substituents on the fifth position of the benzene ring in Chlorsulfuron could hasten its degradation rate, apparently in acidic soil, this work on Metsulfuron-methyl showed more convincing results. Two novel compounds (I-1 and I-2) were designed and synthesized, and they still retained potent herbicidal activity in tests against both dicotyledons and monocotyledons.
View Article and Find Full Text PDFA series of novel 5-substituted-1,3,4-oxadiazole Mannich bases and bis-Mannich bases have been conveniently synthesized in good yields. Their structures were characterized by IR, (1)H NMR, (13)C NMR and elemental analysis. The preliminary bioassay results indicated that some of the compounds showed promising in vitro fungicidal activities towards several test plant fungi; some of them exhibited significant herbicidal activities against Brassica campestris and excellent in vitro inhibitory activities against rice ketol-acid reductoisomerase (KARI).
View Article and Find Full Text PDFTo discover potent insecticides targeting ryanodine receptors (RyRs), a series of novel anthranilic diamides analogues (12a-12u) containing N-substituted phenylpyrazole were designed and synthesized. These compounds were characterized by (1)H NMR, (13)C NMR, and HRMS, and the structure of compound 12u was confirmed by X-ray diffraction. Their insecticidal activities indicated that these compounds displayed moderate to excellent activities.
View Article and Find Full Text PDFA series of novel carboxamide compounds 19a-19j, 20a-20j and 22a-22d containing piperazine and arylsulfonyl moieties have been synthesized. The bioassay results showed that some compounds exhibited favorable herbicidal activities against dicotyledonous plants and many of them possessed excellent antifungal activities. Among 24 novel compounds, some showed superiority over the commercial fungicides Chlorothalonil, Dimethomorph, Thiophanate-methyl, Iprodione, and Zhongshengmycin at 500 mg/L concentration.
View Article and Find Full Text PDFIntroduction: Our aim was to determine differences between the outcomes of treatment using microimplant anchorage compared with headgear anchorage in adult patients with bimaxillary protrusion treated with self-ligating brackets.
Methods: Thirty-one adult orthodontic patients (13 men, 18 women; age, 25.87 ± 3.
Background: The aim of the study was to investigate the association between single nucleotide polymorphism (SNP) of vitamin D receptor (VDR) gene and clinical progress of benign prostatic hyperplasia (BPH) in Chinese men.
Methods: The DNA was extracted from blood of 200 BPH patients with operation (progression group) and 200 patients without operation (control group), respectively. The genotypes of VDR gene FokI SNP represented by "F/f" were identified by PCR-restriction fragment length polymorphism.
Angle Orthod
November 2015
Objective: To assess oral health-related quality of life (OHRQoL) in young adult patients with malocclusion and to measure the association between orthodontic treatment need and OHRQoL.
Materials And Methods: The study sample comprised 190 young adults aged 18 to 25 years who were attending orthodontic clinics at the Faculty of Dentistry. The Index of Orthodontic Treatment Need-Dental Health Component was used to measure orthodontic treatment need.