北五味子的超临界萃取及产物的HPLC-APCI-MS/MS分析

优化超临界流体萃取北五味子中木脂素类成分的提取工艺,对萃取物中所含有效成分的归属进行分析鉴定.以五味子总木脂素为评价指标,采用正交实验法和不同影响因素系统考察法对CO2 -SFE萃取北五味子中木脂素类成分提取工艺进行优化,利用液相色谱-大气压化学电离质谱联用法(HPLC-APCI-MS/MS)分析鉴定产物结构.确定了最...     

迎春花叶提取物在磷酸介质中对钢的缓蚀作用

采用失重法研究了迎春花(Jasminum nudiflorum Lindl.)叶提取物(JNLLE)在H3PO4介质中对冷轧钢缓蚀作用,考察了缓蚀剂浓度(20～200mg/L)、温度(20～50℃)、腐蚀浸泡时间(6～48 h)、酸浓度(1.0～10.0 mol/L)对缓蚀性能的影响.结果表明:JNLLE在1.0 mo...     

维生素C对中国对虾的营养和免疫作用及其最适剂型

论述了维生素Ｃ对中国对虾的营养作用，对对虾蜕壳的影响，以及对虾对维生素Ｃ的缺乏症；ＬＡＰＰ对中国对虾缺氧耐受力及免疫抵抗力的影响；各类维生素Ｃ产品在不同条件下的稳定性；不同剂型维生素Ｃ对中国对虾生长的影响。     

Angiotensin I-converting enzyme inhibitory activity of Acetes chinensis peptic hydrolysate and its antihypertensive effect in spontaneously hypertensive rats

Peptic hydrolysate with angiotensin I-converting enzyme (ACE) inhibitory activity was prepared from Acetes chinensis . The 3 kDa ultrafiltration filtrates (UF-IV) of the desalted hydrolysate exerted a potent ACE inhibitory activity with IC50 being 0.67 mg mL⁻¹. The fractions with molecular weight located between 611 and 240 Da achieved a total percentage of 63.6% in the UF-IV, with a mean peptide length of about 5.6–2.1. Gastrointestinal digestions were simulated on the hydrolysate and UF-IV and addressed their effect on the ACE inhibitory activity. The ACE inhibitory activity of the UF-IV could survive or be maintained in active form by simulated gastrointestinal digestion. Furthermore, the UF-IV exerted potent antihypertensive effect after oral administrations were given to spontaneously hypertensive rats (SHR) at a dose of 900 mg kg⁻¹ body weight. In conclusion, the UF-IV could serve as useful antihypertensive peptides in the prevention and treatment of hypertension and other associated disorders.     

Molecular cloning and characterisation of cytoplasmic glutamine synthetase gene BcGS1 from non‐heading Chinese cabbage

BACKGROUND: Glutamine synthetase (GS; EC 6.3.1.2) is a key enzyme of nitrogen (N) assimilation, catalysing the synthesis of glutamine from ammonium and glutamate. Plants have two types of GS isoenzyme that are localised in different compartments: one in the cytosol (GS1) and the other in the chloroplast (GS2). GS1 is the major form of GS in plant roots and directly converts ammonium taken up by plant roots to glutamine. RESULTS: The GS1 gene cDNA of non‐heading Chinese cabbage (Brassica campestrisssp. chinensis Makino) cultivar ‘Suzhouqing’ was isolated by RT‐PCR (real‐time polymerase chain reaction) and (5′/3′)‐RACE (rapid amplification of cDNA ends) techniques. It was classified as GS1 by sequence alignment and motif search and named B. campestris ssp. chinensis Makino GS1 (BcGS1). Subcellular localisation analysis showed that BcGS1 was distributed in the cytoplasm of cells. BcGS1 was expressed in all parts, but mainly in the roots, which was verified by northern blotting analysis. Additionally, its expression was influenced by the N source concentration. CONCLUSION: These results suggest that BcGS1 is a novel member of the GS family in plants. BcGS1 was significantly related to N assimilation in non‐heading Chinese cabbage, demonstrating that this gene plays an important role in plant growth and development. Copyright © 2010 Society of Chemical Industry     

曲水园古松柏生长环境的土壤质量与评价

为制定促进古松柏良好生长及复壮措施提供科学依据,对曲水园古白皮松、古桧柏进行了土壤质量调查与分析,结果表明：古白皮松、古桧柏生长环境的土壤pH值较高、而土壤的EC值、有机质和速效氮的含量偏低,由此会对古白皮松、古桧柏的生长造成不利影响;经测试,古白皮松和古桧柏土壤中的有效磷含量达丰富水平,土壤中的微生物含量,古白皮松比古桧柏要高。对存在的问题提出了相应的改良措施。     

超声法提取紫荆花红色素的工艺研究

应用超声法提取了紫荆花红色素.用正交实验优化了超声提取的工艺条件.结果表明,各因素对提取率的影响大小依次为:料液比>超声功率≈提取剂体积分数>提取时间;对2.000 g紫荆干花提取2次,最佳提取条件为:提取剂为85%乙醇,料液比1∶20(g∶mL),提取时间15 min,超声功率70 W.超声技术省时、高效、节能,适用紫荆花天然色素的提取.     

The antioxidant properties of alcoholic extracts from Sambucus nigra L. (antioxidant properties of extracts)

The antioxidant properties of alcoholic extracts from the leaves, berries and flowers of Sambucus nigra L. are estimated by means of DPPH and β-carotene/linoleic acid methods, and considered in relation to the extraction temperature (in the range 20-200 °C) and to the level of flavonoids most representative for this plant. The extracts of S. nigra act as antioxidants neutralizing the activities of free radicals and inhibiting the co-oxidation reactions of linoleic acid and β-carotene. There is no direct correlation between the level of flavonoids in the extracts and their antioxidant activity. The data presented show that the extraction temperature strongly influences the antioxidant properties of the extracts, especially in the case of leaves.     

荔枝果实加工新技术研究进展

荔枝是我国南方的一种特产名果,是我国在国际市场上最有竞争力的水果之一。本文综述了荔枝果实加工现状和新技术,展望了荔枝果实加工产品的发展前景,旨在为荔枝果实加工新产品的开发和荔枝加工业的发展提供参考。