彩色豆马勃子实体的化感作用及其化感物质的分离鉴定

彩色豆马勃能与松树、桉树形成外生菌根,研究其次生代谢产物对植物的影响具有重要意义。用水、乙醇和丙酮抽提彩色豆马勃的子实体,发现这些抽提物对稗草和水稻幼苗生长有极显着的抑制作用。丙酮抽提物对狼尾草和油菜幼苗生长有抑制作用。子实体的丙酮抽提物用硅胶柱色谱分离得到2个纯化合物,可鉴定为豆马勃内酯(Pisolactone)和麦角甾醇。该2个化合物在400μg·ml^-1浓度下均显着抑制稗草幼苗根生长。豆马勃内酯在100μg·ml^-1浓度下仍然极显着抑制稗草幼苗根生长.     

水杨酸延缓猕猴桃果实采后衰老与精氨酸分解代谢的关系

采用1.0 mmol·L^-1水杨酸(SA)处理‘徐香’猕猴桃果实,测定果实在常温(23±2)℃贮藏过程中失重率、硬度、多聚半乳糖醛酸酶(PG)活性和丙二醛(MDA)含量,以及精氨酸分解代谢相关酶活性和物质含量的变化,探究SA处理延缓猕猴桃果实采后衰老的作用机理。结果显示：(1)与对照(不处理)相比,贮藏第20天时,SA处理果实的失重率较对照降低13.77%,硬度较对照提高78.25%,表明SA处理有效抑制了猕猴桃果实硬度和鲜重的下降。(2)贮藏第20天时,SA处理果实的PG活性(13.61 μg·g^-1·h^-1)显著低于对照(16.77 μg·g^-1·h^-1);猕猴桃果实中的MDA含量在贮藏第15天时差异最大,SA处理较对照降低33.40%。(3)与对照相比,在贮藏过程中SA处理显著促进了果实中鸟氨酸的累积以及精氨酸脱羧酶和鸟氨酸脱羧酶活性的升高,同时抑制了多胺氧化酶和二胺氧化酶活性,并显著提高了猕猴桃果实中多胺(腐胺、精胺、亚精胺)的累积。(4)与对照相比,SA处理显著诱导了猕猴桃果实中一氧化氮合酶活性的增强,并促进了果实中一氧化氮(NO)的累积,且在贮藏第5天以后果实中的NO含量显著高于对照。研究发现,SA能够显著延缓常温下猕猴桃果实的采后衰老进程,这可能与SA触发了果实中精氨酸分解代谢的不同途径有关。     

脱落酸与镉处理对辣椒果实中辣椒素和维生素C含量的影响

本文以湘研15号辣椒为材料,研究了脱落酸（ABA）与镉（Cd^2＋）在辣椒米实不同发育时期对辣椒素和维生素C含量的影响,并分析了处理后辣椒素、维生素C含量变化与POD活性以及叶片光合特征之间的关系。结果表明：湘研15号辣椒植株经ABA与Cd^2＋处理后果实中辣椒素含量峰值分别比对照提高了80．4％与61．4％,POD活性均显著升高,二者处理后辣椒果实中的辣椒素、POD变化趋势基本一致,处理后叶片光合速率均有下降趋势。ABA处理后果实中维生素C含量在转色期比对照降低12．8％～21．7％,叶片中叶绿素相对值显著增加;Cd^2＋处理后果实中维生素C含量在转色期比对照减少18％～25％,红熟期减少13％-26％,叶片叶绿素相对值在红熟期之前比CK显著降低。     

芒果核仁的化学成分及其抑菌活性

从杧果(Mangifera indica L.)果实核仁中分离得到6种化合物。经光谱分析及与文献对照,分别鉴定为没食子酸(1)、没食子酸甲酯(2)、没食子酸乙酯(3)、间-二没食子酸甲酯(4)、对羟基苯甲酸(5)和丁二酸单甲酯(6),它们均为首次从芒果核中获得。用琼脂平板稀释法测定了化合物1~5对7种细菌和4种真菌生长的抑制活性。结果表明,化合物1对金黄色葡萄球菌(Staphylococcus aureus)、表皮葡萄球菌(S. epidermidis)、干燥棒状杆菌(Corynebacterium xerosis)和藤黄微球菌(Micrococcus luteus)的最小抑制浓度(MIC)为50~100 µg mL-1,化合物4对绿脓杆菌(Pseudomonas aeruginosa)有抑制活性。     

低温和GA3对凤丹种子萌发及碳氮代谢物和内源激素含量的影响

研究了低温(4℃)和300 mg·L-1GA3对凤丹(Paeonia suffruticosa‘Fengdan’)种子萌发过程中子叶、上胚轴和叶原基形态及种胚中碳氮代谢物(包括淀粉、可溶性糖和可溶性蛋白质)和内源激素(包括ZR、IAA、ABA和GA)含量的影响。结果表明:GA3处理后第11天凤丹种子上胚轴萌发,且形态细长;经低温处理后第27天上胚轴萌发,且形态较粗壮。低温处理后种子萌发的幼苗叶片较大、株高居中、根系发育较好、须根多且长,生长状况总体上优于对照和GA3处理组。与处理后第3天相比,对照和低温处理后第27天以及GA3处理后第11天,种胚中淀粉、可溶性糖、ZR、IAA和GA含量升高,ABA含量降低;而对照和低温处理后第27天种胚中可溶性蛋白质含量降低,GA3处理后第11天可溶性蛋白质含量无显著变化。各处理组凤丹种子蛋白质电泳条带的相对分子质量多集中在12 000~80 000,在对照和低温处理后第27天蛋白质条带颜色均较处理后第11天略深,但条带数量不变。研究结果显示:低温及GA3处理均可导致凤丹种胚中碳氮代谢物和内源激素含量变化,促进种胚发育及上胚轴生长,但低温处理更有利于上胚轴萌发及幼苗生长。     

黄瓜果实中ARF和Aux/IAA基因对外源激素的应答

以非单性结实黄瓜自交系‘6429’为试验材料,对当天开花的果实进行CPPU、Spd、NAA、2,4-D和IAA等5种生长物质处理,以清水为对照,选取9个ARF基因(Csa019264、Csa019265、Csa009209、Csa009210、Csa021954、Csa012237、Csa012805、Csa015176、Csa010564)和5个Aux/IAA基因(Csa003118、Csa012115、Csa016715、Csa006680、Csa018571)设计特异引物,取开花当天与花后第2、4天的果实及其茎、叶作RT-PCR分析。结果显示,9个ARF基因的表达水平显示出了很大的差异,Csa012805在所有激素处理后的果实中都有较高水平的表达而清水处理中未检测到;5个Aux/IAA基因中的4个在6种处理后的果实及茎叶中都有表达,推测是组成型表达基因,Csa016715在激素处理后的果实中比清水处理的未发育果实中的表达水平高。推测Csa012805和Csa016715这2个基因对黄瓜果实膨大起促进作用。     

萘乙酸控制后季稻秧苗生长的研究

盆栽和大田试验证明萘乙酸(500 ppm左右)能有效地抑制后季稻秧苗生长。叶面喷施萘乙酸水溶液以后,秧苗的株高和地上部干重明显减小;这种对生长的抑制效应以在人工气候室玻璃房中较田间条件下为大。在田间比较良好的栽培条件下,喷施萘乙酸后约经二周,萘乙酸对秧苗生长的抑制作用不仅解除,反而转现为促进效应。当时进行插秧,因稻株能长出较多的健壮新根,所以比对照吸肥多,生长旺盛。秧苗期叶面喷施萘乙酸不影响稻株发育,处理植物的抽穗和成熟都正常,其稻谷产量不低于对照;或稍高于对照。根据所得结果,我们初步认为萘乙酸有可能作为一种生长调节物质在农业生产中用于控制后季稻秧苗的生长,使秧苗株高减低,便于移栽或进行机插。     

西芹种子浸提液处理后黄瓜枯萎病菌弱毒菌株的筛选

研究了西芹种子浸提液对黄瓜枯萎病菌菌落生长的抑制作用及浸提液处理后病菌致病力的变化.结果表明:在连续5代浸提液作用下,50 mg·mL-1的西芹种子乙醇、丙酮浸提液处理与其对照相比,显著抑制了黄瓜枯萎病菌菌落的生长;50 mg·mL-1的西芹种子蒸馏水浸提液处理在1～3代培养过程中,显著抑制了黄瓜枯萎病菌菌落的生长,而在4～5代培养过程中,与其对照相比,抑制菌落生长的差异不显著;用各代经西芹不同浸提液处理的黄瓜枯萎病菌接种到黄瓜上进行致病力测定,并于1周开始发病后调查病情,西芹种子丙酮、乙醇和蒸馏水浸提液处理的病情指数分别由第1代的26.7％、20.8％和22.5％降为第5代的17.5％、3.3％和18.3％;3种浸提液与其对照相比,其病情指数也表现降低,其中,乙醇浸提液处理与其对照差异达显著水平;接种至第5代时,乙醇浸提液处理的病情指数为3.3％,病菌毒力的致弱作用最强.综上所述,西芹种子浸提液不但抑制黄瓜枯萎病菌菌落的生长,而且还能弱化病菌的毒力.实验通过浸提液的连续处理获得了黄瓜枯萎病菌的弱毒菌株.     

酸角种子多糖对菠萝的保鲜效应(简报)

在热带地区的气候条件下,酸角种子多糖水溶液处理采后菠萝能降低果实的呼吸强度和水分蒸腾,减缓营养成分的消耗,有一定的保鲜作用。在旱季、雨季里,经处理贮藏30天的菠萝腐烂率与失重率分别为8.09～22.5％和16.9～17.6％,而对照则分别为34.9～42.3％和21.5～24.6％。     

荔枝果实采后钙处理对三种酶活性的影响

用不同浓度的Ｃａ对荔枝果实采后处理,测定果实中的果胶酯酶,多聚半乳糖醛酸酶和纤维素瓣活性变化。发现用４％的钙的处理,对上述各酶活性都有一定的抑制作用;在冷藏条件下,还能推这三种酶活性高峰的来临,甚至使之出现,从而延缓了果实的衰老。ｌ     

獐牙菜属植物的研究概况

本文对龙胆科獐牙菜属植物的化学和生理活性研究进行了概略的回顾。迄今为止,约有40种獐牙菜属植物有文献报道。从这些植物中已分离出100多种不同类型的化合物,包括(口山)哃、黄酮、甙类、萜类及少部分内酯、生物碱和有机酸类化合物。这些化合物有多种生理活性,如:镇静、抗结核菌、强壮、退热、轻泻、肝保护、抗惊厥、增压及治疗胃病和心血管疾病等。还可制成各种制剂用于生发、护肤、驱虫等。     

Novel isoniazid embedded triazole derivatives: Synthesis,antitubercular and antimicrobial activity evaluation

In the present study, a series of new isoniazid embedded triazole derivatives have been synthesized. These compounds were evaluated for their in vitro antitubercular and antimicrobial activities. Among the screened compounds, six have exhibited potent antitubercular activity against Mycobacterium tuberculosis H37Rv strain with MIC value 0.78 μg/mL, whereas, three compounds have displayed activity with MIC value ranging from 1.56 to 3.125 μg/mL. The cytotoxicity of the active compounds was studied against RAW 264.7 cell line by MTT assay and no toxicity was observed even at 25 μg/mL concentration. The five compounds have displayed good antimicrobial activities. Molecular docking have been performed against mycobacterial InhA enzyme to gain an insight into the plausible mechanism of action which could pave the way for our endeavor to identify potent antitubercular candidates. We believe that further optimization of these molecules may lead to potent antitubercular agents.     

Chemical Constituents of the Seed Cake of Camellia oleifera and Their Antioxidant and Antimelanogenic Activities

There is a growing interest in the exploitation of agricultural byproducts. This study explored the potential beneficial health effects from the main biowaste, tea seed pomace of Camellia oleifera Abel (Theaceae), produced when tea seed is processed. Eighteen compounds were isolated from the 70% EtOH extract of the seed cake of C. oleifera. Their structures were determined by ESI‐MS, ¹H‐ and ¹³C‐NMR together with literature data. All fractions and compounds were evaluated for the antioxidant and melanogenesis inhibitory activities. As the result, AcOEt fraction has the best in vitro antioxidant and antimelanogenesis activities, compounds 7 – 12 and 15 showed remarkable antioxidant activity, compounds 4 , 6 , 8 , and 15 – 17 exhibited superior inhibitory activities against melanogenesis. Furthermore, tyrosinase inhibitory activity assay suggested that compound 8 could suppress melanogenesis by inhibiting the expression of tyrosinase.     

Insect growth regulatory and larvicidal activity of chalcones against Aedes albopictus

Widespread use of chemical insecticides has resulted in development of insect resistance and natural products with biological activities could become an attractive alternative to control insect pests. In order to find more effective insecticides for controlling mosquito, various mosquitocidal compounds are studied. Recently, juvenile hormone antagonists (JHANs) have been found to be to safe and effective insecticides for control of mosquito. In order to identify novel insecticidal compounds with JHAN activity, several chalcones were surveyed on their JHAN activities and larvicidal activities against Aedes albopictus larvae. Among them, 2′‐hydroxychalcone and cardamonin showed high levels of JHAN and mosquito larvicidal activities. These results suggested that chalcones with JHAN activity could be useful for control of mosquito larvae.     

新型含硅氨基甲酸酯衍生物的合成、杀虫活性及抗乙酰胆碱酯酶活性研究

合成了14个(1-甲硫基亚乙基)氨基甲基氨基甲酸酯(灭多威)1的新型含硅衍生物3。 测定了其杀虫活性和抗乙酰胆碱酯酶活性。结桌表明该类化合物具有很好的杀虫活性,在50μg/mL浓度下,对粘虫Mythimna separata Walker几乎全部具有100%杀灭效果。以美洲大蠊Periplaneta americana为试材,大部分化合物的抗乙酰胆碱酯酶活性与母体灭多威1相当     

Alkaloids from Corals

Alkaloids, which are generally basic N‐containing compounds, have been found in a variety of natural sources. Recently, the interest in alkaloids from corals increased significantly due to their remarkable bioactivities. This review deals with the chemical structures and biological activities of alkaloids in corals. The literature has been covered up to June 2011, and a total of 102 alkaloids from the 51 publications are discussed and reviewed. Some of these compounds showed various biological properties, such as cytotoxic, antibacterial, insecticidal, antifouling, and other activities.     

Chemical Constituents of Plants from the Genus Eupatorium (1904–2014)

Eupatorium (family: Compositae), which comprises nearly 1200 species, is distributed throughout tropical America, Europe, Africa, and Asia. Up to now, the reported constituents from the genus Eupatorium involve flavonoids, terpenoids, pyrrolizidine alkaloids, phenylpropanoids, quinonoids, essential oils, and some others, altogether more than 300 compounds. Studies have shown that Eupatorium and its active principles possess a wide range of pharmacological activities, such as cytotoxic, antifungal, insecticidal, antibacterial, anti‐inflammatory, and antinociceptive activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activities from Eupatorium in vivo and in vitro. Increasing amount of data supports application and exploitation for new drug development.     

Novel 2′-hydroxylfurylchalcones: synthesis and biological activity

Twelve novel 2′-hydroxylfurylchalcones have been synthesized by Claisen-Schmidt condensation with galactosylisomaltol, a reagent prepared from lactose. The procedures are environmentally benign and economical. All the compounds are identified by IR, ¹H NMR and ¹³C NMR spectroscopy and by mass spectrometry. Preliminary bioassays indicate that all the title compounds show moderately high herbicidal activities against the height and/or the fresh weight of the seedlings of cucumber, rape, amaranth, wheat, sorghum and Chinese sprangletop at 7.5 g of active ingredient per hm². However, the compounds exhibit weak fungicidal activities against cucumber powdery mildew, and no activities against rice blast, cucumber grey mould and cucumber downy mildew. The structure-activity relationships are discussed. The present work demonstrates that 2′-hydroxylfurylchalcones could be used as potential lead compounds for further study of novel herbicides.     

中国海绵天然产物的研究

据统计,从海洋生物的天然产物中获得药物或药物先导化合物的几率要比陆源生物高,海绵是海洋中除珊瑚以外的第二大生物资源。在海绵体内已发现许多高活性的化合物。中国海绵的研究主要集中在南海。南海海绵种类多、数量大,样品采集比较容易。本文统计调查了国内外海绵研究的现状,重点综述中国已研究的海绵种类、所获得的天然化合物以及相关产物的药理研究结果,对上述研究的特点与存在的不足进行了分析、讨论。     

Carboline derivatives based on natural pityriacitrin as potential antifungal agents

Carboline alkaloids are a class of important heterocyclic natural products, which usually present extensive bioactivities. During the course of our research for active compounds from natural products, the pityriacitrin and pityriacitrin B belonged carboline alkaloids have been isolated from a Chinese Burkholderia sp. NBF227, which indicated potential antifungal activities. So, in order to develop these carboline alkaloids as potential fungicidal agents, a series of pityriacitrin derivatives were investigated for their antifungal activities against Phytophthora capsici, Sclerotinia sclerotiorum, Botrytis cinerea and Rhizoctonia solani, and the results demonstrated that compounds 4, 10 and 19 displayed broad-spectrum antifungal activities. In addition, in vivo bioassay also indicated that compounds 4 and 10 could protect the pepper leaves and grape fruits against infection by P. capsici and B. cinerea, respectively. The possible mechanism of antifungal action for these compounds was also explored.