海拔对黄土高原地区赤霞珠果实酚类物质含量及抗氧化活性的影响

【目的】研究黄土高原地区2个不同海拔条件下赤霞珠果实酚类化合物含量及抗氧化活性的差异,为不同立地条件下酿酒葡萄的种植提供理论依据。【方法】以高海拔(1 280 m)坡地和低海拔(909 m)谷地种植的赤霞珠果实为研究对象,对其理化指标、酚类物质含量、抗氧化活性(DPPH自由基清除法、铜离子还原能力和超氧自由基清除能力)及10种单体酚(没食子酸、安息香酸、丁香酸、咖啡酸、阿魏酸、香豆酸、水杨酸、儿茶素、槲皮素、芦丁)含量进行分析,比较海拔对赤霞珠果实酚类物质含量及抗氧化活性的影响。【结果】坡地和谷地赤霞珠果实糖酸比分别为18.7和20.3,与坡地赤霞珠相比,谷地赤霞珠的成熟度较好;坡地和谷地赤霞珠果实总黄烷醇含量分别为330和348 mg/kg,花色苷含量分别为1 182和929 mg/kg,与坡地赤霞珠相比,谷地赤霞珠总黄烷醇含量较高,但花色苷含量较低;坡地和谷地赤霞珠果实抗氧化能力分别为9 715和9 824μmol/kg(DPPH自由基清除法),26 033和37 109μmol/kg(铜离子还原能力),71.6%和74.0%(超氧自由基清除能力),以上3种抗氧化方法的测定结果均表明,谷地赤霞珠果实抗氧化能力强于坡地,其中以铜离子还原能力测定结果差异最大;对坡地和谷地赤霞珠果实中所含的10种单体酚进行检测,除香豆酸外,其他9种单体酚含量均表现为谷地高于坡地,其中以安息香酸、咖啡酸、阿魏酸、儿茶素和槲皮素的差异较为明显。【结论】海拔对赤霞珠果实的品质有一定影响,但影响程度在不同品质指标间存在差异;在黄土高原地区,低海拔谷地赤霞珠果实的成熟度、酚类化合物含量及抗氧化能力均优于高海拔坡地赤霞珠果实。     

农药助壮素电极的研制

研制成以四间甲苯硼酸钾为活性载体的农药助壮素选择性电极。该电极在ｐＨ４．５￣９．５的１０＾－２ｍｏｌ／Ｌ氯化锂水溶液中，测定助壮素的线性响应范围为１．２×１０＾－２￣７．５×１０＾－６ｍｏｌ／Ｌ，斜率为５４．０，检测下限为１．４×１０＾－６ｍｏｌ／Ｌ。电极性能良好，适用于助壮素的快速分析。     

混菌发酵黑青稞甜醅工艺优化及品质特性研究

为改善单一菌株发酵制备青稞甜醅的风味与口感,提高其质量品质,本试验采用米根霉和酵母菌为发酵菌株,以氨基酸态氮含量及感官评分为指标,确定混菌发酵黑青稞甜醅的最佳工艺条件,并比较单一菌株发酵黑青稞制品与混菌发酵黑青稞制品中酚类物质含量、抗氧化活性及风味物质组成的差异。结果表明,混菌发酵黑青稞制品最佳发酵条件为:发酵温度33℃,发酵时间48 h,菌种比例(酵母菌J7∶米根霉)1∶1.20,接种量6.81%,在此条件下混菌发酵黑青稞制品的氨基酸态氮含量为9.32 mg·100 g^-1,感官评分为95.48分。与单一菌株发酵黑青稞制品相比,混菌发酵黑青稞的黄酮含量(32.22 mg·100 g^-1)、 多酚含量(230.68 mg·100 g^-1)及DPPH自由基清除能力(95.03 μmol·L^-1)显著提高。气相色谱-质谱(GC-MS)分析结果表明,酵母菌单独发酵的黑青稞中共检出33种挥发性风味物质,米根霉单独发酵的黑青稞中共检出41种挥发性风味物质,混菌发酵的黑青稞中共检出46种挥发性风味物质,其中酯类和醇类是3种发酵方式黑青稞制品的主要风味组分。混菌发酵黑青稞的醇类、酯类和酸类种类及含量均显著高于其余两种发酵方式,其相对含量分别达到59.09%、29.44%和6.46%,风味更丰富。综上分析,混菌发酵使黑青稞制品在功能及风味方面具有一定的优势。本研究结果为混菌发酵黑青稞制品的开发和应用奠定了基础。     

视频扫描测定油菜饼粕自由基清除活力方法的研究

用视频扫描平板色谱和稳定自由基1，1－二苯基－2－间三硝苯基偕腙肼（DPPH）检测油菜饼粕自由基清除活力的方法，研究抗坏血酸，维生素E，酚酸和类黄酮等17种常见酚类化合物对自由基的清除活力，发现自由基清除面积与样品量的相关系数为0．947－0．996，检测下限为40－690ng，以维生素E指数为清除活力指标，视频扫描法与常规标准比色法的测定结果具有良好的相关性，测定油菜饼粕提取液自由基清除活力发现，68－75％的化合物具有自由基清除能力，Rf值为0．41的化合物清除活力最高，占总活力的38％。     

Statistical research on marine natural products based on data obtained between 1985 and 2008

Since the 1960s, more than 20,000 compounds were discovered from marine organisms. In this paper we performed a quantitative analysis for the novel marine natural products reported between 1985 and 2008. The data was extracted mainly from the reviews of Faulkner and Blunt [1-26]. The organisms producing these marine natural products are divided into three major biological classes: marine microorganisms (including phytoplankton), marine algae and marine invertebrate. The marine natural products are divided into seven classes based on their chemical structure: terpenoids, steroids (including steroidal saponins), alkaloids, ethers (including ketals), phenols (including quinones), strigolactones, and peptides. The distribution and the temporal trend of these classes (biological classes and chemical structure classes) were investigated. We hope this article provides a comprehensive perspective on the research of marine natural products.     

Isolation of a new natural product and cytotoxic and antimicrobial activities of extracts from fungi of Indonesian marine habitats

In the search for bioactive compounds, 11 fungal strains were isolated from Indonesian marine habitats. Ethyl acetate extracts of their culture broth were tested for cytotoxic activity against a urinary bladder carcinoma cell line and for antifungal and antibacterial activities against fish and human pathogenic bacteria as well as against plant and human pathogenic fungi. The crude extract of a sterile algicolous fungus (KT31), isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex P.C. Silva exhibited potent cytotoxic activity with an IC₅₀ value of 1.5 μg/mL. Another fungal strain (KT29) displayed fungicidal properties against the plant pathogenic fungus Cladosporium cucumerinum Ell. et Arth. at 50 μg/spot. 2-Carboxy-8-methoxy-naphthalene-1-ol (1) could be isolated as a new natural product.     

Phosphite-mediated enhancement of defence responses in Agrostis stolonifera and Poa annua infected by Microdochium nivale

The ascomycete fungus Microdochium nivale is one of the most damaging pathogens of cool season turfgrass. Prevention of and recovery from infection is costly to many sports facilities each year. In recent years, use of many chemical plant protectants has been restricted and turfgrass managers have increasingly sought alternative measures for disease control. The use of phosphite has been shown to be effective in reducing M. nivale disease symptoms in Agrostis stolonifera and Poa annua. The aim of this research was to assess initial defence responses in M. nivale-infected turfgrass, specifically total phenolic content and hydrogen peroxide generation, to determine the effect phosphite treatment has on these responses and on suppression of symptoms. Phenolic compounds and H₂O₂ are shown to be components of host responses. Phosphite treatment led to enhanced accumulations of total phenolic content, and when applied sequentially or singly to greenhouse plants, it led to significant reductions in M. nivale disease symptoms compared to phosphate-treated plants or controls. H₂O₂ extractions indicated that while phosphite treatment increased H₂O₂ generation compared to controls, the effect was no different to the responses in phosphate-treated plants.     

不同产地沙棘果的成分分析

通过沙棘甘油三酯和甘油磷脂中的糖、果酸(气相色谱-质谱法,TMS衍生物)、矿物质(FAAS,ETAAS)、挥发性物质(顶部空间气相色谱-质谱法)、Vc(高压液相色谱)和脂肪酸(气相色谱-质谱法,甲基酯)的分析方法,优化不同产地的沙棘果。对1997年10-11月采集的中国沙棘果(CH)和8月底采集的芬兰沙棘果(FI)和俄罗斯沙棘果(RU)的成分进行比较,得到了为今后开展更广泛的沙棘项目所需要的足够的资料。中国沙棘果汁中的Vc含量极高,平均8g/l(4.2-13.2g/l),是芬兰沙棘果汁中含量的5倍。主要矿物元素的含量比其它可食用的浆果中丰富得多,钾是沙棘果(6-14g/kg,干重)和沙棘籽(5-9g/kg,干重)中的主要矿物质之一,在一些样品中铅和镉含量的增加表明存在轻微的污染。压榨的沙棘果汁中糖的含量从1-20g/100ml有很大的变化,含量最高的是晚秋收获的中国沙棘果,最低的是8月收获的芬兰沙棘果。糖主要是葡萄糖(占总糖分的50％以上)、果糖及葡萄糖衍生物。苹果酸和奎宁酸是主要的果酸(77％-97％),含量为每100ml果汁中4.2-9.1g。果汁上部油脂的特点是形成了C2-C5n-、iso-、和ante-iso乙醇,C4-C5n-,iso,及ante-ISO酸,也呈现出挥发性油脂的籽油乙醇前体。不同的产地和采收时间对挥发物有着明显的影响,整个果中的含油量为2％-11％(鲜重),籽中的含     

Rhizodeposition and net release of soluble organic compounds by pine and beech seedlings inoculated with rhizobacteria and ectomycorrhizal fungi

Summary A lysimetric experiment was performed in a greenhouse to evalute root deposition and net release of soluble organic compounds after 1 and 2 years from pine and beech seedlings inoculated with an ectomycorrhizal fungus (Laccaria laccata) and/or rhizobacteria (Agrobacterium radiobacter for beech and Agrobacterium sp. for pine). Total C compounds released in the rhizosphere of both plants increased after inoculation with the bacteria or ectomycorrhizal fungus. The rhizobacteria increased root and plant growth and rhizodeposition, but the mycorrhizal fungi appeared to increase only root deposition. Soluble C compounds, collected after 2 years, represented only 0.1–0.3% of the total C compounds released into the rhizosphere, and were modified by inoculation with the microorganisms. After inoculation with the bacteria, levels of sugars and amino acids decreased in pine and beech rhizospheres, whereas organic acids increased, especially in the pine rhizosphere. In the rhizosphere of mycorrhizal beeches, sugar and amino acids increased, and organic acids differed from those released from non-mycorrhizal beeches. In the mycorrhizal pine rhizosphere, however, all compounds decreased. Following dual inoculations, mycorrhizal colonization increased, no effect on plant growth was observed, and virtually no organic acids were detected.