蒿属和千里光属植物中桉烷型倍半萜的光谱特征

本文就菊科中的两个大属蒿属和千里光属植物中一类典型倍半萜成分——桉烷型倍半萜的光谱特征进行综述.     

长穗桑中的Diels-Alder型加合物

从长穗桑的茎皮中首次分离到9个Diels—Alder型加合物,通过NMR、MS等波谱分析手段分别鉴定为mulberrofuran K（1）,mulberrofuran G（2）,guangsangon L（3）,kuwanon J（4）,kuwanonx（5）,guangsangonG（6）,guangsangon B（7）,guangsangon D（8）,kuwanon P（9）。化合物1—9进行了抗氧化活性筛选。结果表明,在10^-5M浓度下,化合物1,2,5—7,9对Fe^2＋-半胱氨酸诱导的肝微粒体脂质过氧化产生的丙二醛（malondialdehyde,MDA）有抑制作用（抑制率大于50％）。     

黄鞘蕊花中的艾里莫芬烷型倍半萜(英文)

从黄鞘蕊花 (ColeusxanthanthusC .Y .WuetY .C .Huang)的乙酸乙酯部分首次分离得到 3个艾里莫芬烷型倍半萜类化合物 ( 1～ 3) ,其结构由NMR波谱技术及单晶X衍射分析确定。其中 ,化合物 1为新化合物 ,命名为 8,9_断裂_艾里莫芬_1 ( 1 0 ) ,7( 1 1 )_二烯_8,1 2_内酯_9_酸。首次对化合物 2 ( 2 ,9_二氧代优瑞坡森 )和 3( 9_氧代宽眼菊素 )的1H NMR和13C NMR谱进行了全归属。     

中国红豆杉细胞培养物中两种紫杉烷的分离鉴定

从中国红豆杉细胞培养物中分离得到两个紫杉化合物,它们的结构为1β－ 羟基巴卡亭Ⅰ（1β-hydroxy baccatinⅠ）和云南红豆杉甲素（yunnanxane）。     

毛花猕猴桃中的两个新三萜化合物

从毛花猕猴桃(Actinidia eriantha Benth.)的根中,分离到β-谷甾醇,胡萝卜甙,熊果酸,2α,3α,24-三羟基-12-烯-28-乌苏酸,同时还得到两个新的三萜化合物,命名为毛花猕猴桃酸A(eriatic acid A)和毛花猕猴桃酸B(eriantic acid B)。根据光谱数据及化学反应证明,其结构分别为24-乙酰氧基-2α,3α-二羟基-12-烯-28-乌苏酸和2β,3β,23-三羟基-12-烯-28-乌苏酸。     

费氏丙酸杆菌两个亚种的分离与鉴定

用亨格特（Hungate）厌氧技术从不同奶制品分离出3株丙酸杆菌Propionibacterium,编号为PTC－1,PTC－2和PTC－3。细胞呈多形态,杆状,革兰氏阳性,不形成芽孢,不运动,菌落在PYG深层洋菜中呈双凸透镜状,白至土黄色,从葡萄糖、乳糖等8种碳水化合物发酵产酸,葡萄糖发酵产物包括大量丙酸和乙酸,少量异丁酸,琥珀酸和CO₂。厌氧至耐氧。PTC－1的DNA的GC百分含量测定值为67.8mol％（Tm）。三株菌的特性很接近,只在硝酸盐还原和牛奶凝固特性有差     

万年蒿中两个新贝壳杉烷型二萜的分离与结构测定

自菊科蒿属植物万年蒿(Artemisia sacrorum Ledeb.)地上部分首次分得3个单体化合物(两个贝壳杉烷型二萜和一个酸性化合物),经理化常数测定及光谱分析(UV,IR,~1H-NMR,~(13)C-NMR,MS)鉴定其结构分别为3α,16α-二羟基贝壳杉烷-200-O-β-D-葡萄糖甙(Ⅰ)(3α,16α-dihydroxykaurane-20-O-β-D-glucoside(Ⅰ)),3α,6α-二羟基贝壳杉烷-19-O-β-D-葡萄糖甙(Ⅱ)(3α,16α-dihydroxykaurane-19-O-β-D-glucoside(Ⅱ))和1,4-二咖啡酰奎宁酸(Ⅲ)(1,4-dicaffeylquinic acid(Ⅲ))。(Ⅰ)和(Ⅱ)为两个未见报道的新化合物。     

罗汉果中甘露醇的分离和鉴定

从罗汉果的新鲜果实中提取分离出一种非三萜葡萄糖甙的甜味成分,经化学和光谱测定鉴定为D-甘露醇。     

两株副溶血弧菌烈性噬菌体的分离鉴定

研究旨在筛选烈性噬菌体, 为副溶血弧菌(Vibrio parahaemolyticus, Vp)病害防控增加新的选择。以副溶血弧菌Vp13为宿主菌, 通过二层琼脂平板法筛选, 分离到了2株烈性噬菌体SX-2和SX-F。对其形态结构进行了透射电镜观察, 利用DNase I、 RNase A、Mung Bean Nuclease和Hind Ш酶进行噬菌体核酸类型鉴定, 并对噬菌体的裂解谱、最佳感染复数、一步生长曲线进行了测定。透射电镜观察结果显示: SX-2核衣壳头部长约110 nm, 宽约50 nm, 尾部长约150 nm, 宽约10 nm, 为典型的复合体制; SX-F核衣壳呈正六边形, 长约为56.86 nm,宽约50.74 nm, 未观察到尾部, 推测为正二十面体对称; 核酸测定结果显示两者均为线性双链DNA。依据国际病毒分类委员会第九次报告, SX-2符合肌尾噬菌体科特征, SX-F符合盖噬菌体科特征。噬菌体SX-2和SX-F对85株弧菌裂解结果显示: 噬菌体SX-2能够裂解23株副溶血弧菌和1株溶藻弧菌(Vibrio alginolyticus), 噬菌体SX-F能够裂解19株副溶血弧菌和1株溶藻弧菌。SX-2和SX-F的最佳感染复数均为0.0001。一步生长曲线结果显示: SX-F的潜伏期约10min, 裂解期约70min, 裂解量为116.2; 噬菌体SX-2的潜伏期小于10min, 裂解期大约70min, 裂解量为209.3。两株噬菌体生物学特性表明SX-2与SX-F均为烈性噬菌体, 这为进一步探讨噬菌体防治技术奠定了基础。     

黄毛楤木皂甙的分离鉴定

从黄毛楤木(Aralia decaisneana Hance)根皮分得3种皂甙(Ad-Ⅰ、Ad-Ⅱ、Ad-Ⅲ)和1种由 Ad-Ⅲ水解得到的次级甙(Ad-Ⅳ),经光谱(IR、FAB-MS、~1H-NMR、~(13)C-NMR)和化学分析(酸、碱水解法),分别鉴定为楤木皂甙 A、3-O-[α-L-阿拉伯呋哺糖-(1→4)-β-D-葡萄吡喃糖醛酸]-齐墩果酸甙、3-O-[β-D-半乳吡喃糖-(1→4)-β-D-半乳吡喃糖-(1→3)-β-D-葡萄吡喃糖醛酸]-齐墩果酸-28-O-β-D-葡萄吡喃糖甙、3-O-[-β-D-半乳吡喃糖-(1→4)-β-D-半乳吡喃糖-(1→3)-β-D-葡萄吡喃糖醛酸]-齐墩果酸甙。前两种皂甙系首次从该植物分得,后两种为新化合物。     

POPULATION GENETIC STRUCTURE AND GENE FLOW ACROSS ARID VERSUS MESIC ENVIRONMENTS: A COMPARATIVE STUDY OF TWO PARAPATRIC SENECIO SPECIES FROM THE NEAR EAST

To shed light on the potential effects of xeric/arid versus mesic environments on plant population genetic structure and patterns of gene flow, we have compared allozyme and cpDNA haplotype variation in populations of two closely related, highly outcrossed, and largely wind-dispersed winter annuals of Senecio (Asteraceae). The species form a distinctive zone of parapatric distribution in the Near East by differing in their ecogeographical regimes. Senecio vernalis mainly thrives in the mesic Mediterranean life zone of Israel, whereas S. glaucus inhabits either xeric maritime or arid (semi-) desert sites. Significant differences in allozymic population subdivision among S. vernalis (θ_n = 0.04; Nm_n = 5.85) and S. glaucus (θ_n = 0.12; Nm_n = 1.85) largely resulted from topogeographical substructuring present within the latter species. Because of the similarity of within-region estimates of population structure for S. glaucus with those measured among populations of S. vernalis, it appears unlikely that ecological “aridity” factors per se are important in influencing levels of population differentiation in these species. Based on hierarchical F-statistics and tests of isolation by distance, we further conclude that geographical topologies influence the level and mode of nuclear gene flow (via pollen and/or seed) among and within subsets of S. glaucus populations, although without providing a complete barrier to interregional dispersal (dNm_reg = 2.16) and without promoting allopatric differentiation via drift. The allozymic data further suggested that S. vernalis and S. glaucus form a zone of secondary contact in the Near East, accompanied by an almost complete interspecific barrier to nuclear gene flow (dnNm_sp = 0.253). However, to account for the considerable sharing of cpDNA haplotypes, both at the intra- and interspecific level, it is necessary to invoke either (1) selection acting against alien nuclear but not cytoplasmic DNA; or (2) the sporadic immigration of cpDNA via seed with large homogenizing effects on cytoplasmic population structure over time.