FOOD CHEMISTRY
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2018
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IF 4.946
Lanxin Luo,Yan Cui,Jinhui Cheng,Bairui Fang,Zongmin Wei,Baoshan Sun
To develop an efficient method for degradation of grape seed and skin proanthocyanidins polymers into oligomers, an optimized sulphurous acid degradation conditions for grape seed with the temperature of 60 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, and for grape skin with the temperature of 40 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, were established. Afterwards, HSCCC and prep-HPLC were used to fractionate and isolate individual proanthocyanidin oligomers from the degradation products. Total of ten dimeric or trimeric procyanidins were obtained, and most of them presented high yield (from 0.7 mg to 13.6 mg per run in grape seed and from 0.5 mg to 4.1 mg per run in grape skin) and high purity (over 90%). The proposed method provides a new way for large preparation of oligomeric proanthocyanidins from naturally abundant and wasted polymeric ones.
研究领域:
植物化学
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食品科学
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天然产物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NATURAL PRODUCT RESEARCH
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2020
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IF 2.158
Xiaomei Li,Xiaoman Li,Jing Zhu,Haoxin Wang,Chunhua Lu
One new carbamothioic S-acid derivative (1) and five known kigamicin derivatives (2–6) were isolated from the fermentation extract of Amycolatopsis alba DSM 44262Δabm9 elicited by N-acetyl-D-glucosamine. HPLC-DAD-UV analyses indicated that the DSM 44262Δabm9 strain did not produce these metabolites originally and the production of 1–6 was induced by adding 25 mM N-acetyl-D-glucosamine in the culture medium. The structures of 1–6 were identified on the basis of NMR spectroscopic data and high-resolution ESIMS. These results highlight that addition of N-acetyl-D-glucosamine in the microbial culture medium could activate cryptic gene expression, induce and increase the production of new or known secondary metabolites.
研究领域:
微生物学
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天然产物化学
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药物开发
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2023
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IF 4.8
Yang Mei,Si Yang,Chenxi Li,Xinyu Li,Yuewen Yu,Rong Liu,Wenliang Chen,Xiaoli Wang,Kexin Xu
Mercury ion (Hg 2+ ) detection plays a crucial role in safeguarding the environment and protecting human health. In this study, we developed a microfluidic biosensing platform that utilizes a phosphorothioate-RNA (PS-RNA) probe and gold-coated magnetic nanoparticles to quantify Hg 2+ visually. The PS-RNA probe was linked to gold-coated magnetic nanoparticles via Au–S interaction and biotin–avidin interaction and then combined with polystyrene microspheres to form a self-assembled structure called a magnetic bead-AuNP-probe-polystyrene (MAPP) bead. We designed and fabricated a microfluidic chip that contained only a magnetic separator and a particle trap. The presence of Hg 2+ cut the PS-RNA probe, leading to the separation of magnetic beads and polystyrene microspheres. The MAPP was removed by the magnetic separator, while the cut polystyrene microspheres flowed along the channel and accumulated in the particle trap, forming a long visible strip. The length of the polystyrene microsphere strip was proportional to the Hg 2+ concentration. The microfluidic biosensing platform exhibited high sensitivity and specificity for Hg 2+ detection, with a detection limit of 21.9 nM. By integrating the microfluidic magnetic manipulation system with a sensitive nucleic acid probe, we developed an automated and visual biosensor that is a valuable reference for the on-site visual detection of heavy metal ions.
研究领域:
环境科学
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分析化学
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生物技术
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
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2024
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IF 3.9
Jingwen Yao,Jiaying Tong,Dan Zhao,Dong Chen,Yuhong Ma,Wantai Yang
The reversible addition-fragment chain transfer (RAFT) alternating copolymerization of 2-hydroxyethyl vinyl ether (HEVE) and dimethyl maleate (DMM) is achieved with S -(cyanomethyl) O -ethyl carbonodithioate (CMX) as medaitor and 2,2′-azobis(2-methylpropionitrile) (AIBN) as radical initiator. The effects of monomer concentrations, comonomer feeding ratios, molar ratio of monomer to CMX and solvent on the copolymerization and copolymer structure are systematically investigated. The living feature of the HEVE and DMM copolymerization is demonstrated by the linear increasement of the molecular weights with the monomer conversions, and relatively narrow molecular weight distributions of the copolymers. With dimethyl carbonate as solvent, poly(HEVE- alt -DMM) with M n = 5200 and M w / M n = 1.34 are synthesized at [HEVE]/[DMM]/[CMX]/[AIBN] = 100/100/3/1. The alternating structure of the copolymer is demonstrated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and proton nuclear magnetic resonance spectroscopy ( 1 H NMR). The both α, ω-end groups are mainly originated from the moiety of CMX. To further demonstrate the living feature of the alternating copolymerization, chain extension and block copolymerization are also carried out. With poly(HEVE- alt -DMM) as macro-CTA ( M n = 5200, M w / M n = 1.34), the chain-extension reaction has been successfully realized ( M n = 9600, M w / M n = 1.70), and the block copolymer with vinyl neonanoate as monomer also successfully synthesized ( M n = 9800, M w / M n = 1.42). Graphical
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）