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Biosci Biotechnol Biochem ; : 1-11, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382820


Quinoa crude polysaccharides (QPS) were extracted from Chenopodium quinoa Willd. The soluble non-starch polysaccharide fraction (QPS1) was subsequently purified by DEAE-52 cellulose and Sephadex G-50 gel chromatography, using QPS as raw materials. Its chemical structure was identified using FT-IR, NMR, AFM, SEM and Congo red staining. High performance gel permeation chromatography (HPGPC) was used to determine molecular weight, and composition by HPLC. QPS1, with a molecular weight of 34.0 kDa, was mainly composed of mannose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose at a molar ratio of 2.63:2.40:1.64:6.28:1.95:2.48:5.01. In addition, we evaluated the ameliorative effects of QPS1 on the improvement of anti-cyclophosphamide (CTX)-induced immunosuppression in ICR mice. The result exhibited significantly immune-enhancing activity: QPS1 successfully improved the content of IFN-γ, IL-6, IFN-ɑ, IgM and lysozyme (LYSO) in serum for three weeks, enhanced the phagocytic function of mononuclear macrophages and ameliorated delayed allergy in mice.

Biotechnol Appl Biochem ; 66(2): 192-201, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30578642


Limonin, a compound of highly oxidized triterpenoids, has potential functions in preventing or slowing the occurrences of many diseases. In this study, five different bacterial strains were isolated and identified from Citrus maxima (Burm.) Merr. cv. Shatian Yu. Morphological characteristics and 16S rRNA gene sequencing identified them as Bacillus spp, in which two limonin-producing endophytes named P and P9 were discovered by high-performance liquid chromatography and mass spectrometry using an inorganic salt medium and two natural media; also the production was greater in natural medium 1 (4.377 and 0.299 mg/L, respectively) than in natural medium 2 (0.159 and 0.025 mg/L, respectively). The growth and fermentation characteristics of strain P were studied, and during the liquid cultivation of Bacillus sp. P, limonin began to accumulate at the eighth hour in the inorganic salt medium, peaked at the 16th hour, and then decreased sharply. Single-factor experiments revealed that the optimum fermentation conditions for limonin production included 14-H-old cells, 15% inoculum, and 3 g/L glucose.

Bacillus/crescimento & desenvolvimento , Bacillus/isolamento & purificação , Citrus/microbiologia , Limoninas/biossíntese
Rapid Commun Mass Spectrom ; 25(14): 2027-34, 2011 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-21698685


Chloroethynitrosoureas (CENUs) are important alkylating agents widely used in the treatment of cancers. Decomposition of CENUs generates active electrophilic ions that damage DNA, including the formation of dG-dC crosslinks which represents the most important cytotoxic mechanism of CENUs. In this work, a high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method was employed to analyze the dG-dC crosslinks induced by 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (meCCNU, Semustine). The direct quantitation of dG-dC crosslinks in oligonucleotide duplexes was achieved by the selected reaction monitoring (SRM) mode using synthesized (15) N(3) -labeled dG-dC as an internal standard. Methods of enzymatic digestion and HPLC separation were developed for obtaining separation and reproducibility of the dG-dC peak in chromatograms. The limit-of-detection (LOD) was determined to be 0.08 nM and the limit-of-quantification (LOQ) was determined to be 0.16 nM. The linearity of the calibration curve was 0.9997 over the range of 0.08 to 32 nM. The precision and accuracy of the method ranged from 1.1 to 6.6% and 96 to 109%, respectively. The recovery of the dG-dC crosslink in the enzymatic hydrolysates from the oligonucleotide duplex was determined to be from 91 to 106%. The results of the validation study indicate that the method is suitable for quantifying dG-dC crosslinks in DNA. Consequently, this method was used to determine meCCNU-induced dG-dC crosslinks in four duplexes with different GC contents. The results showed that the crosslinking fraction (CF) increased as the GC content in the duplex increased, and a relatively low CF was observed in the early period of the reaction.

Reagentes para Ligações Cruzadas/química , Nucleotídeos de Desoxicitosina/análise , Desoxiguanosina/análise , Semustina/química , Espectrometria de Massas em Tandem/métodos , Antineoplásicos Alquilantes/química , Cromatografia Líquida de Alta Pressão/métodos , Nucleotídeos de Desoxicitosina/química , Nucleotídeos de Desoxicitosina/metabolismo , Desoxiguanosina/química , Desoxiguanosina/metabolismo , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade