砂生槐的一新变型——白花砂生槐

描述了豆科苦参属砂生槐的一个新变型:白花砂生槐[Sophora moorcroftiana(Benth.)Baker f.albiflora S.H.Yang].原变型的花冠为蓝紫色,而新变型的花冠为白色.     

古国槐叶片溶磷内生真菌的筛选及其促生潜力初探

该试验从周公庙古国槐叶片内分离、筛选具有溶磷能力的内生真菌,采用溶磷圈法和钼锑抗比色法测定其溶解无机磷的能力,同时测定其回接后对国槐无菌苗叶绿素、可溶性蛋白质、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的影响,探究内生真菌的溶磷能力及其促生效应。结果表明:(1)从古国槐叶片中分离出的55株内生真菌中,28株具有溶磷能力,其中溶磷能力较强的活性菌株有12株:ZG-7为拟盘多毛孢(Pestalotiopsis sp.),ZG-9、ZG-23、ZG-32、ZG-36和ZG-53为镰刀菌(Fusariumsp.),ZG-15和ZG-34为曲霉(Aspergillus sp.),ZG-39和ZG-51为链格孢(Alternariasp.),ZG-42为木霉(Trichoderma sp.),ZG-48为附球菌(Epicoccumsp.)。(2)曲霉属真菌ZG-15和ZG-34的溶磷圈直径(d)及其与菌落直径(D)的比值d/D均高于其他菌株,对Ca_3(PO_4)_2的溶解能力最强(1 238.28和941.22mg·L-1),并极显著高于其他菌株(P0.01)。(3)4株内生真菌ZG-7、ZG-9、ZG-15和ZG-48回接至国槐无菌苗10d后,可从苗根组织的皮层细胞中观察到内生菌丝,其中黑曲霉(Aspergillus niger)ZG-15可显著提高国槐无菌苗的叶绿素含量、可溶性蛋白质含量、SOD、POD活性(P0.05),从而维持幼苗的正常生长和提高其抗逆能力,为该试验得到的促生潜力优势内生真菌,可为古国槐的有效保护及林木溶磷生物菌肥的生产提供依据。     

Quinolizidine alkaloid status of Styphnolobium and Cladrastis (Leguminosae)

Reports of quinolizidine alkaloids in Styphnolobium Schott and Cladrastis Raf. (Leguminosae) conflict with their position in recent molecular phylogenies because they are not members of a major clade of quinolizidine alkaloid-accumulating taxa. The alkaloid status of these two genera was therefore re-investigated using gas chromatography–mass spectrometry. Quinolizidine alkaloids could not be detected in extracts of leaves, flowers or seeds of S. japonicum (L.) Schott, nor in leaves of S. affine (Torrey & A. Gray) Walp., C. delavayi (Franch.) Prain, C. kentukea (Dum.-Cours.) Rudd or C. platycarpa Mak. In contrast, Calia secundiflora (Ortega) Yakovlev, also currently placed outside the major clade of quinolizidine alkaloid-producing genera in molecular phylogenies, was confirmed to accumulate a range of quinolizidine alkaloids.     

苦参水提液的杀菌效果

采用悬液定量杀菌试验,对苦参水提液的杀菌效果进行实验室研究。研究发现,苦参水提液对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、白假丝酵母菌和黑曲霉均具有明显的杀菌作用。通过模拟现场试验,苦参水提液起到了显著地杀菌效果。     

越南槐根的抗HIV活性成分研究

为研究越南槐(Sophora tonkinensis)根的抗HIV蛋白酶活性成分及其分子对接机制,采用硅胶、MCI、Sephadex LH-20等多种色谱分离方法,对越南槐根的化学成分进行分离,采用HIV蛋白酶对化合物进行体外抗HIV活性筛选,运用分子对接手段初步探究活性化合物与HIV-1蛋白酶的结合机制。结果表明,从越南槐中共分离得到8个化合物,根据波谱数据分别鉴定为三叶豆紫檀苷(1)、苦参碱(2)、N-acetylnicotinamide (3)、2′-O-甲基腺苷(4)、毛蕊异黄酮苷(5)、玫瑰花苷(6)、环广豆根素(7)、芒柄花苷(8),此外还分离得到塑化剂衍生物邻苯二甲酸二(2-乙基)己酯(9)和邻苯二甲酸二异丁酯(10)。抗HIV蛋白酶活性测试显示化合物1和2的IC50分别为13.2和38.6μg/m L,分子对接表明其与HIV蛋白酶有一定的结合作用。化合物3～5为首次从该植物中分离得到,化合物1和2显示中等的抗HIV蛋白酶活性。     

Kurarinol, tyrosinase inhibitor isolated from the root of Sophora flavescens

It is well known that flavanones, sophoraflavanone G 1, kurarinone 2, and kurarinol 3, from the root of Sophora flavescens, have extremely strong tyrosinase inhibitory activity. This study delineates the principal pharmacological features of kurarinol 3 that lead to inhibition of the oxidation of l-tyrosine to melanin by mushroom tyrosinase (IC₅₀ of 100 nM). The inhibition kinetics analyses unveil that compounds 1 and 2 are noncompetitive inhibitors. However similar analysis shows kurarinol 3 to be a competitive inhibitor. Compounds 1 and 2 exhibited potent antibacterial activity with 10 μg/disk against Gram-positive bacteria, whereas kurarinol 3 did not ostend any antibacterial activity. Interestingly, kurarinol 3 inhibits production of melanin in S. bikiniensis without affecting the growth of microorganism. It is thus distinctly different from the other tyrosinase inhibitors 1 and 2. In addition, kurarinol 3 manifests relatively low cytotoxic activity (EC₅₀>30 μM) compared to 1 and 2. To account for these observations, we conducted molecular modeling studies. These suggested that the lavandulyl group within 3 is instrumental in the interaction with the enzyme. More specifically, the terminal hydroxy function within the lavandulyl group is most important for optimal binding.     

山豆根地上部分的酪氨酸酶抑制活性成分筛选研究

壮药山豆根,为豆科植物越南槐(Sophora tonkinensis)的干燥根和根茎,是非常重要的广西道地药材。为了更加合理地开发利用山豆根的地上部分,阐明其化学物质基础,该研究采用多种现代色谱分离方法对山豆根地上部分进行了系统分离,并通过现代波谱学方法对分离得到的单体化合物进行了结构鉴定,同时测试了单体化合物对酪氨酸酶的抑制活性。结果表明:(1)从山豆根地上部分分离得到10个化合物,分别为水杨酸(1)、对羟基苯甲酸(2)、木犀草素(3)、8-异戊烯基山萘酚(4)、槲皮素(5)、大豆素(6)、芒柄花素-7-O-β-D-葡萄糖苷(7)、刺芒柄花素(8)、鸢尾黄素(9)、金雀异黄素(10),所有化合物均首次从山豆根的地上部分中分离得到;(2)酪氨酸酶抑制活性的试验测试结果表明化合物4、7和9对酪氨酸酶均具有较强的抑制作用,其中化合物4的酪氨酸酶抑制活性最强,IC₅₀值为(1.58 ± 0.31)× 10^-5 mol·L^-1。该研究丰富了山豆根地上部分的化学物质基础及其生物活性,为山豆根非药用部位的深入开发利用奠定了基础。     

苦豆子表型性状多样性分析及综合评价

该研究以自然分布的内蒙、宁夏、甘肃、新疆、陕西等23个不同地理来源(种源)的野生苦豆子种子及其播种于内蒙古鄂托克前旗同质园内的当年生植株为材料,采用方差分析、主成分分析、聚类分析等方法对种子长、宽、千粒重以及植株的叶长、叶宽、叶面积、叶形指数、苗高、地径及生物量等10个表型性状的多样性进行了研究。结果表明:各个表型性状种源间均呈极显著差异,其中种子表型性状的变异系数为5.24%,植株表型性状的变异系数为18.34%,表明种子性状的稳定性高于植株性状。同时,10个性状的表型分化系数均高于70%,说明苦豆子表型多样性主要来源于种源间的表型变异;各种源苦豆子种子性状的表型分化系数均值高达97.55%,且种长、千粒重分别与采集地经度、纬度和海拔等环境因子呈极显著相关性,说明种子表型性状受环境因素的影响较大;相关性分析显示,苦豆子植株性状叶长(LL)、叶面积(LA)分别与种子性状千粒重(TW)、种长(SL)和种宽(SW)有显著相关性,暗示表型性状中的可遗传变异影响;利用主成分和聚类分析对23个种源苦豆子进行综合评价,筛选出生物量较大、苗高较高、千粒重较重、叶面积较大等综合表现较好的6个种源,共分为两类,分别是DK、JY、WY、WH、ETK和YN,这为苦豆子种质资源定向开发以及选育和栽培提供了一定的理论支撑和基础材料。     

pH对槐角愈伤组织黄酮类化合物产量的影响

培养基酸碱度是影响植物生长和次生代谢的重要因素之一。将生长稳定的国槐槐角愈伤组织在不同pH值的B5悬浮培养基中培养,比较其生长状况、生物量及苯丙氨酸转氨酶活性和黄酮类化合物的产量。结果表明:pH为6.6时,国槐细胞生长状况好,且不同pH下的苯丙氨酸转氨酶活性差异显著;培养基呈弱酸性(即6.6±0.05)时,细胞黄酮类化合物含量较高。综合生长天数和产量,最佳的收获时期为继代后的第25～30天。     

野生越南槐组织特异性内生真菌组及体外抗病原菌功能

有益微生物组能帮助宿主植物防御病害。越南槐的根、茎和种子在野外环境下健康发芽生长,而栽培越南槐各组织极易感病。为了探明利用野生越南槐有益内生真菌组防治宿主病害的可能,该文在分离健康野生越南槐根、茎和种子内生真菌的基础上,并结合形态学和ITS序列特征鉴定内生真菌,通过系统发育树、α-多样性指数和β-多样性指数分别分析各内生真菌组的系统进化、多样性和相似性,通过琼脂块法和平板对峙法测试内生真菌组的体外抗病原菌功能。结果表明:(1)从越南槐根、茎和种子内生真菌组分别分离鉴定131株23个分类单元、108株23个分类单元、64株11个分类单元;(2)特有属多且所有种均为特有种显示根、茎和种子内生真菌组在属种进化上具有组织特异性;(3)根-茎/根-种子/茎-种子间极低的β-多样性显示根、茎和种子各内生真菌组间的物种相似性极低;(4)高的α-多样性显示越南槐根、茎和种子均有丰富多样的内生真菌组;(5)各内生真菌组三分之一以上的分类单元在体外均能拮抗供试病原菌,根茎内生真菌组显示了强广谱的体外抗病原细/真菌功能,种子内生真菌组显示了强广谱的体外抗病原真菌功能。该研究结果表明健康野生越南槐根、茎和种子内部均存在有益内生真菌组,其具有生物多样性、组织特异性以及强广谱的体外抗病原菌功能,在宿主各组织的抗病性方面可能发挥重要作用。这些结果将为进一步利用有益真菌组防治栽培越南槐各组织病害提供了材料和实验基础。     

中国膨果豆属(豆科)一新组合

原簇毛黄耆亚属的部分种类从黄耆属中分出,在此基础上恢复了膨果豆属,由此也产生了许多新组合。其中,新组合蒺藜叶膨果豆包含了原蒺藜叶黄耆和甘青黄耆。为验证该分类处理的合理性,该文统计分析了蒺藜叶黄耆和甘青黄耆在果实形态上的差异,同时比较了二者的地理分布式样。结果表明:甘青黄耆和蒺藜叶黄耆之间存在着明显区别,甘青黄耆种级的分类学地位应予以保留,新组合为甘青膨果豆[Phyllolobium tangutica(Batalin)Y.Kang M.L.Zhang]。     

渗透剂对白刺花体细胞胚成熟及萌发的影响

该研究以蔗糖、麦芽糖、山梨醇及PEG(6000)为渗透剂,探讨了不同渗透剂对白刺花体细胞胚发育、胚成熟及萌发的影响。结果表明:白刺花下胚轴形成的胚性愈伤组织接种至MS+2,4-D 0.2 mg·L~(-1)+NAA 1.0 mg·L~(-1)+6-BA 2.0 mg·L~(-1)+TDZ 1.0 mg·L~(-1)+蔗糖40 g·L~(-1)+谷氨酰胺100 mg·L~(-1)+植物凝胶3g·L~(-1)的培养基上,体细胞胚发生率高达66. 21%,总胚数为79个; 7%蔗糖可使体细胞胚成熟率高达64.36%,同时也可提高多子叶畸形胚形成; 2%麦芽糖+2%山梨醇+4%蔗糖组合使体细胞胚成熟率最高达88.89%,畸形胚比例最低; 30 g·L~(-1)PEG培养时,体细胞成熟率最高,为82.35%;鱼雷期的体细胞胚最合适转接,可使体胚萌发率达90.58%,复合糖上培养得到的成熟体细胞胚生根率最高,为87.47%。这为实现白刺花体细胞胚育苗奠定了理论基础,并提供了可行的方案。     

西藏不同生长地砂生槐群体种子生物碱含量及其相关性分析

为了明确不同群体间和群体内砂生槐天然种子富含生物碱含量与组成的差异,该研究选取来自西藏“一江四河”流域、海拔2 900～4 100 m范围内10个群体的砂生槐种子作为研究材料,采用高效液相色谱法,测定10个群体300个单株种子重要生物碱(氧化苦参碱、苦参碱、槐果碱、槐定碱)含量,应用SPSS软件分析了地理分布特征与生物碱含量之间的相关性及群体遗传变异关系,以筛选生物碱含量较高的群体,为砂生槐药物开发利用提供依据。结果表明：(1)10个群体的砂生槐种子中均含有氧化苦参碱、苦参碱和槐果碱,含量依次为：氧化苦参碱(46.18～64.08 mg/g)>苦参碱(1.14～9.82 mg/g)>槐果碱(0.08～1.16 mg/g),其中氧化苦参碱占生物碱总量的90%以上,且群体4中含量最高(64.08±7.37 mg/g);其他微量生物碱在群体3中含量最高;群体间氧化苦参碱、苦参碱和槐果碱均差异极显著(P＜0.01)。(2)氧化苦参碱群体内和群体间变异相对较小,苦参碱和槐果碱群体内和群体间变异系数均较大,而且氧化苦参碱和槐果碱的群体间变异均大于群体内变异,苦参碱的群体间变异小于群体内变异。(3)氧化苦参碱与海拔呈显著正相关关系(r = 0.117^*),苦参碱与海拔、经度和纬度均呈极显著负相关关系(r ＜ -0.326^**),其他关系不显著。氧化苦参碱与苦参碱和槐果碱均呈显著负相关关系(r ＜-0.162^**),而苦参碱与槐果碱呈显著正相关关系(r =0.789^**)。(4)聚类分析将10个群体聚为4类,各类间的距离差异比较大,且大多与地理因素有关。     

香槐属分类学研究随记

基于对标本和文献的比较研究,确认豆科香槐属(Cladrastis Raf.)中小叶香槐(C.parvifolia C.Y.Ma)、藤香槐(C.scandens C.Y.Ma)、秦氏香槐(C.chingii DuleyVincent)与本属分布最广的翅荚香槐[C.platycarpa(Maxim.)Makino]为同种植物。其中,小叶香槐被处理为翅荚香槐的一变种,即C.platycarpa var.parvifolia(C.Y.Ma)Z.Q.Song,D.X.XuS.J.Li,藤香槐与秦氏香槐被处理为翅荚香槐原变种的两个新异名。同时讨论了翅荚香槐的分类地位及其散布。     

疏花长柄山蚂蝗复合体(豆科)的修订

通过文献、标本研究,结合野外考察及数据统计分析,确认疏花长柄山蚂蝗复合体包括4种1亚种,讨论了各分类群的重要性状,并给出了新的检索表。将湘西长柄山蚂蝗(Hylodesmum laxum subsp.falfolium)处理为原亚种的新异名;订正了《中国植物志》和《Flora of China》等著作中该类群的几个错误的地理分布,记载了我国几个省区的分布新记录,并给出了凭证标本。     

NaCl胁迫对苦豆子幼苗光合机构及生物量积累的影响

该研究通过测定盐生药用植物苦豆子幼苗气体交换、叶绿素荧光参数及生长指标,研究了中度(200mmol/L NaCl)和重度(400mmol/L NaCl)盐胁迫对其生长特性的影响,探讨盐生植物对盐化环境的生理响应机制。结果显示:(1)中度盐胁迫1d后,苦豆子幼苗光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)及胞间二氧化碳浓度(C_i)显著低于对照,随着胁迫时间延长,P_n下降显著,而气体交换参数降低不明显,C_i值甚至有上升趋势;重度盐胁迫处理1d后,苦豆子气体交换值出现了显著降低,随着胁迫时间延长,降低程度增大;中度盐胁迫导致苦豆子光合速率出现下降的原因是由气孔因素和非气孔因素共同作用的结果,而重度盐胁迫下,Pn的下降主要是非气孔因素引起的。(2)处理1d后,相对于对照组,中度和重度盐胁迫下的苦豆子幼苗最大光化学效率(F_v/F_m)、光化学猝灭系数(qP)、实际光化学效率(Φ_(PSⅡ))出现了不同程度的降低,而重度盐胁迫下降低更加显著;处理5d后,中度盐胁迫荧光参数变化不明显,但重度盐胁迫处理下降低显著。(3)随着胁迫程度的加重,幼苗含水量及生长指标(株高、根长、干重)降低幅度加大,以致严重抑制了植株生长。研究表明,盐生植物苦豆子对盐胁迫的耐受性也有一定限度,其在200mmol/L NaCl胁迫下植株光合作用受到轻微抑制,但能维持正常生长,而在400mmol/L NaCl胁迫下光合生理受到严重抑制,且随着胁迫时间的延长,受到伤害程度加重,甚至死亡。     

Parameters influencing asymmetric synthesis of (R)-mandelonitrile by a novel (R)-hydroxynitrile lyase from Eriobotrya japonica

(R)-Mandelonitrile was successfully synthesized by an enzymatic transcyanation reaction of benzaldehyde and acetone cyanohydrin catalyzed by a hydroxynitrile lyase from Eriobotrya japonica (EjHNL) in an aqueous-organic biphasic system. The effects of pH, temperature, organic solvent, substrate concentration and enzyme concentration on the initial activity and enantioselectivity of the enzyme were studied. Both pH and temperature had a large effect on the initial velocity and enantiomeric excess (e.e.) of the product, (R)-mandelonitrile. High enantiomeric purity of the product was observed at low pH and temperature because the non-enzymatic reaction producing racemates of mandelonitrile was almost suppressed. The optimum pH and temperature to obtain high e.e. were pH 4.0 and 10 °C, respectively. Surprisingly, the organic solvents had a significant influence on the initial velocity of the reaction but less influence on the enantiomeric purity of product. The EjHNL was very stable in ethyl acetate, diethyl ether, methyl-t-butyl ether, diisopropyl ether, dibutyl ether and hexane for 12 h. The best solvent for the highest initial velocity and e.e. was diethyl ether with an optimum aqueous phase content of 50% (v/v). The initial reaction rate increase as the aqueous phase content rose, but when the content was more than 50%, a reduction of e.e. was observed. Increasing the concentration of the substrates accelerated the initial velocity, but caused a slight decrease in the e.e. of the product. Under the optimized conditions, the conversion and e.e. of (R)-mandelonitrile for 3 h were 40 and 99%, respectively. The aqueous phase containing the enzyme also showed considerably efficient reusability for 4 batch reactions.     

Flavonoids and isoflavonoids of chemotaxonomic significance from Glycyrrhiza pallidiflora (Leguminosae)

Chemical studies were carried out on the root of Glycyrrhiza pallidiflora (Leguminosae), a licorice of no medicinal or commercial value. Two isoflavone glycosides, wistin and ononin, were isolated as major constituents from the methanol extract. A series of chromatographic separations of the acetone extract yielded isoflavone aglycones (afromosin, 2′,7-dihydroxy-4′-methoxyisoflavone and formononetin), flavanones (liquiritigenin and 4′,7-dihydroxy-6,8-diprenylflavanone), an isoflavan [(-)-vestitol], a pterocarpan [(-)-medicarpin], chalcones (echinatin and isoliquiritigenin), dibenzoylmethanes (licodione and 2′-O-methyl-licodione), a flavone (4′,7-dihydroxyflavone), a 3-arylcoumarin (2′-7-dihydroxy-4′-methoxy-3-arylcoumarin), and a new isoflav-3-ene (2′-7-dihydroxy-4′-methoxyisoflav-3-ene). The co-occurrence of the retrochalcone echinatin and the biogenetically related licodione and 2′-O-methyl-licodione is of particular interest, and suggests that this species is closely related to G. echinata and G. inflata. The biogenesis of the retrochalcone is also discussed in relation to its significance in the chemotaxonomy of sects Echinatae and Bucharicae of the genus Glycyrrhiza.     

Haemolytic activity within the species Fibrocapsa japonica (Raphidophyceae)

Strong haemolytic activity was observed for extracts of 15 Fibrocapsa japonica strains collected from different global regions. The EC₅₀ values ranged between 0.4 × 10⁴ and 1.9 × 10⁴ F. japonica cells ml⁻¹. The relationship between the haemolytic activity observed in the cell extracts and the amount and nature of polyunsaturated fatty acids (PUFAs) was investigated. Between 7% and 89% of the haemolytic activity could be attributed to the amount and toxicity of the PUFAs C18:4n3 (OTA), C20:5n3 (EPA), and C20:4n6 (AA). However, the higher the haemolytic activity of a strain the more it appeared to be caused by haemolytic compounds other than the PUFA's. The EC₅₀ of the extracts with the highest haemolytic activity strongly depended on light intensity and was in line with observations made on Chattonella marina.In the cell extracts of the strains studied brevetoxins were always below detection limits. For strains where 20–35% of the haemolytic activity was not caused by PUFAs, the concentration of these compounds was close to LC₅₀ values reported for fish. Overall the haemolytic activity of the F. japonica strains was in the range of known harmful microalgae. Therefore, PUFAs in combination with potent light dependent haemolytic compounds could be a major cause of ichthyotoxicity observed during F. japonica blooms.