排序方式: 共有30条查询结果,搜索用时 18 毫秒
1.
2.
Products of the reaction between dialdehyde starch and Y-NH2 compounds (e.g. semicarbazide or hydrazine) are effective ligands for metal ions. The usefulness of these derivatives was tested in the experiment, both in terms of the immobilization of heavy metal ions in soil and the potential application in phytoextraction processes. The experimental model comprised maize and the ions of such metals as: Zn(II), Pb(II), Cu(II), Cd(II), and Ni(II). The amount of maize yield, as well as heavy metal content and uptake by the aboveground parts and roots of maize, were studied during a three-year pot experiment. The results of the study indicate the significant impact of heavy metals on reduced yield and increased heavy metal content in maize. Soil-applied dialdehyde starch derivatives resulted in lower yields, particularly disemicarbazone (DASS), but in heavy metal-contaminated soils they largely limited the negative impact of these metals both on yielding and heavy metal content in plants, particularly dihydrazone (DASH). It was demonstrated that the application of dihydrazone (DASH) to a soil polluted with heavy metals boosted the uptake of Zn, Pb, Cu, and Cd from the soil, hence there is a possibility to use this compound in the phytoextraction of these metals from the soil. Decreased Ni uptake was also determined, hence the possibility of using this compound in the immobilization of this metal. The study showed that dialdehyde starch disemicarbazone was ineffective in the discussed processes. 相似文献
3.
Ronnie J.M. Lubbers Adiphol Dilokpimol Jaap Visser Miia R. Mäkelä Kristiina S. Hildén Ronald P. de Vries 《Biotechnology advances》2019,37(7):107396
Aromatic compounds derived from lignin are of great interest for renewable biotechnical applications. They can serve in many industries e.g. as biochemical building blocks for bioplastics or biofuels, or as antioxidants, flavor agents or food preservatives. In nature, lignin is degraded by microorganisms, which results in the release of homocyclic aromatic compounds. Homocyclic aromatic compounds can also be linked to polysaccharides, tannins and even found freely in plant biomass. As these compounds are often toxic to microbes already at low concentrations, they need to be degraded or converted to less toxic forms. Prior to ring cleavage, the plant- and lignin-derived aromatic compounds are converted to seven central ring-fission intermediates, i.e. catechol, protocatechuic acid, hydroxyquinol, hydroquinone, gentisic acid, gallic acid and pyrogallol through complex aromatic metabolic pathways and used as energy source in the tricarboxylic acid cycle. Over the decades, bacterial aromatic metabolism has been described in great detail. However, the studies on fungal aromatic pathways are scattered over different pathways and species, complicating a comprehensive view of fungal aromatic metabolism. In this review, we depicted the similarities and differences of the reported aromatic metabolic pathways in fungi and bacteria. Although both microorganisms share the main conversion routes, many alternative pathways are observed in fungi. Understanding the microbial aromatic metabolic pathways could lead to metabolic engineering for strain improvement and promote valorization of lignin and related aromatic compounds. 相似文献
4.
A radiochemical method for the measurement of ethanol exidation by tissue preparations is described. Ethanol oxidation is determined from the production of [14C]acetaldehyde, quantified as the semicarbazone derivative, from [1-14C]ethanol. The assay is quantitative, reproducible and highly correlated with the NADH-enzymic-spectrophotometric procedure. 相似文献
5.
Hang Xu Xin Su Xiao-qian Liu Kai-peng Zhang Zhuang Hou Chun Guo 《Bioorganic & medicinal chemistry letters》2019,29(23):126726
A series of novel 2,3-dihydro-4H-1-benzoselenin-4-one (thio)semicarbazone derivatives were designed and synthesized by using molecular hybridization approach. All the target compounds were characterized by HRMS and NMR and evaluated in vitro antifungal activity against five pathogenic strains. In comparison with precursor selenochroman-4-ones, the hybrid molecules in this study showed significant improvement in antifungal activities. Notably, compound B8 showed significant antifungal activity against other strains excluding Aspergillus fumigatus (0.25 μg/mL on Candida albicans, 2 μg/mL on Cryptococcus neoformans, 8 μg/mL on Candida zeylanoides and 2 μg/mL on fluconazole-sensitive strains of Candida albicans). Moreover, compounds B8, B9 and C2 also displayed most potent activities against four fluconazole-resistance strains. Especially the MIC values of the hybrid molecule B8 against fluconazole-resistant strains were in the range of 0.5–2 μg/mL. Therefore, the molecular hybridization approach in this study provided new ideas for the development of antifungal drug. 相似文献
6.
The effect of process parameters on the biotransformation of benzaldehyde to L-phenylacetylcarbinol (L-PAC) using a yeast isolate identified as Torulaspora delbrueckii was studied. The maximum yield of L-PAC obtained was (331 mg) per 100 ml biotransformation medium (glucose 3%, peptone 0.6% and at pH 4.5) from 600 mg of benzaldehyde with 8 h of reaction at 30 ± 2 °C. Growing the organism in presence of 3% glucose reduced the biotransformation time to 120 min. Addition of 0.6% acetaldehyde (30–35%) lead to an increase in L-PAC yield to 450 mg%. Semi-continuous feeding of benzaldehyde (200 mg) and acetaldehyde (200 l) four times at 30 min intervals could produce 683 mg of L-PAC/100 ml biotransformation medium. Chiral HPLC analysis of purified L-PAC and PAC-diol showed 99% enantiomeric purity. The cell mass was found to be reusable for biotransformation up to nine times when benzaldehyde and acetaldehyde levels were maintained at (350 mg and 350 l)–(400 mg and 400 l). At concentrations from 450 mg and 450 l to 600 mg and 600 l, however the cell mass could give efficient biotransformation only during one use. 相似文献
7.
8.
Rocha LT Costa KA Oliveira AC Nascimento EB Bertollo CM Araújo F Teixeira LR Andrade SP Beraldo H Coelho MM 《Life sciences》2006,79(5):499-505
Semicarbazones induce an anticonvulsant effect in different experimental models. As some anticonvulsant drugs also have anti-inflammatory activity, the effects of benzaldehyde semicarbazone (BS) on models of nociception, edema and angiogenesis were investigated. BS (10, 25 or 50 mg/kg, i.p.) markedly inhibited the second phase of nociceptive response induced by formaldehyde (0.34%, 20 microl) in mice, but only the highest dose inhibited the first phase of this response. The thermal hyperalgesia and mechanical allodynia induced by carrageenan (1%, 50 microl, i.pl.) in rats were also inhibited by BS (50 mg/kg, i.p.). However, treatment of mice with BS did not induce an antinociceptive effect in the hot-plate model. The paw edema induced by carrageenan (1%, 50 microl, i.pl.) in rats was inhibited by BS (25 or 50 mg/kg, i.p.). Treatment of mice with BS (0.25, 0.5 or 2.5 mg/kg/day, i.p., 7 days) also inhibited angiogenesis induced by subcutaneous implantation of a sponge disc. It is unlikely that the antinociceptive effect induced by BS results from motor incoordination or a muscle relaxing effect, as the mice treated with this drug displayed no behavioral impairment in the rotarod apparatus. In conclusion, we demonstrated that BS presents antinociceptive, antiedematogenic and antiangiogenic activities. An extensive investigation of the pharmacological actions of BS and its derivatives is justified and may lead to the development of new clinically useful drugs. 相似文献
9.
Wenlin Xie Huilin Zhang Jingjing He Jingai Zhang Qiuyan Yu Chunxiang Luo Shangru Li 《Bioorganic & medicinal chemistry letters》2017,27(3):530-532
Two series of novel kojic acid analogues (4a–j) and (5a–d) were designed and synthesized, and their mushroom tyrosinase inhibitory activities was evaluated. The result indicated that all the synthesized derivatives exhibited excellent tyrosinase inhibitory properties having IC50 values in the range of 1.35 ± 2.15–17.50 ± 2.75 μM, whereas standard inhibitor kojic acid have IC50 values 20.00 ± 1.08 μM. Specifically, 5-phenyl-3-[5-hydroxy-4-pyrone-2-yl-methylmercap-to]-4-(2,4-dihydroxyl-benzylamino)-1,2,4-triazole (4f) exhibited the most potent tyrosinase inhibitory activity with IC50 value of 1.35 ± 2.15 μM. The kinetic studies of the compound (4f) demonstrated that the inhibitory effects of the compound on the tyrosinase were belonging to competitive inhibitors. Meanwhile, the structure-activity relationship was discussed. 相似文献
10.
Toshihiko Osawa Harue Ishibashi Mitsuo Namiki Tsuneo Kada 《Biochemical and biophysical research communications》1980,95(2):835-841
Mutagenicity of 1,4-dinitro-2-methyl pyrrole, a new mutagen isolated from the reaction mixture of sorbic acid and sodium nitrite, was found to be destroyed by treatment with ascorbic acid or cysteine. Chemical studies revealed that the loss of mutagenicity was due to reduction from the C-nitro to C-amino group. 相似文献