Chemical constituents from the roots of Fallopia convolvulus (L.) A. Löve

Twenty compounds, including three sterols (1–3), three phenols (4, 14 and 15), four anthraquinones (5, 7, 8 and 16), one chromone (6), two stilbenes (9 and 10), three amides (11–13), three flavonoids (17–19) and one organic acid (20), were obtained by modern phytochemical isolation methods. Their structures were identified by spectroscopic methods and in comparison with the published data in the references. Among them, compound 2, 3, 11 and 13 were firstly discovered from genus Fallopia, and compounds 1, 5–8, 10, 14, 15, 17, 19 and 20 were obtained from F. convolvulus for the first time. The chemotaxonomic significance of these compounds was also discussed, which revealed the relationships between F. convolvulus and some other species of Polygonaceae family.     

Genetic variation in cultivated Rheum tanguticum populations

To examine whether cultivation reduced genetic variation in the important Chinese medicinal plant Rheum tanguticum, the levels and distribution of genetic variation were investigated using ISSR markers. Fifty-eight R. tanguticum individuals from five cultivated populations were studied. Thirteen primers were used and a total of 320 DNA bands were scored. High levels of genetic diversity were detected in cultivated R. tanguticum (PPB = 82.19, H = 0.2498, H_B = 0.3231, I = 0.3812) and could be explained by the outcrossing system, as well as long-lived and human-mediated seed exchanges. Analysis of molecular variance (AMOVA) showed that more genetic variation was found within populations (76.1%) than among them (23.9%). This was supported by the coefficient of gene differentiation (G_st = 0.2742) and Bayesian analysis (θ_B = 0.1963). The Mantel test revealed no significant correlation between genetic and geographic distances among populations (r = 0.1176, p = 0.3686). UPGMA showed that the five cultivated populations were separated into three clusters, which was in good accordance with the results provided by the Bayesian software STRUCTURE (K = 3). A short domestication history and no artificial selection may be an effective way of maintaining and conserving the gene pools of wild R. tanguticum.     

中国蓼属叉分蓼组植物花粉形态的研究

采用光学显微镜和扫描电镜对中国蓼属叉分蓼组20种3变种的花粉形态进行了观察和研究。结果表明其花粉形态大多数为近球形至近长球形,少数为扁球形或长球形;花粉大小为20.4～44.0µm×17.0～34.0µm：从萌发孔看,有3沟、3 孔沟、多沟、散沟;外壁纹饰为微刺—穴状、刺状、粗网状、皱块状。据此,该组花粉可划分为5种类型,即叉分蓼型(Aconogonon-type)、钟花蓼型(Campanulatum-type)、大连线冰岛蓼型(Forrestii-type)、西伯利亚蓼(Sibiricum-type)及多穗蓼型(Polystachyum-type),编制了这些花粉类型检索表。叉分蓼型花粉的主要特征是具3沟,外壁纹饰为微刺-穴状,此种类型的植物有14种2变种。钟花蓼型花粉的主要特征是具6散沟,外壁纹饰为微刺-穴状,此种类型的植物有钟花蓼和绒毛钟花蓼。西伯利亚蓼型花粉的主要特征是具3孔沟,外壁纹饰为皱块状,此种类型的植物有西伯利亚蓼。多穗蓼型花粉的主要特征是具6(~8)多沟,外壁纹饰为粗网状,此种类型的植物有松林蓼及多穗蓼。大连线冰岛蓼型花粉的主要特征是具散沟,外壁纹饰为显著的长刺状,此种类型的植物有大铜钱叶蓼及铜钱叶蓼,结果表明叉分蓼组的花粉形态具有重要的分类学意义,研究结果支持将叉分蓼组上升为属的等级,也支持Knorringia的属的地位,大铜钱叶蓼和铜钱叶蓼应移入Koenigia属中,而松林蓼和多穗蓼仍保留在蓼属中。     

2种蓼科植物体外抑菌试验研究

为研究蓼科植物水蓼、火炭母体外抑菌效果,制备水煎煮液,测定其对枯草芽胞杆菌、大肠埃希菌、金黄色葡萄球菌、黑曲霉、青霉、酿酒酵母的抑菌圈直径、最小抑菌浓度及灭菌前后水煎煮液抑菌效果的变化。结果表明：当水蓼液浓度大于0.6 g/mL,火炭母液浓度大于0.2 g/mL时,2者对细菌的抑菌效果均依次为：金黄色葡萄球菌〉大肠埃希菌〉枯草芽胞杆菌。2种水煎煮液对3种真菌无抑制作用。火炭母液对3种细菌的最小抑菌浓度分别为1/8、1/16和1/64 g/mL,都比水蓼液的结果1/4、1/8和1/16 g/mL低。药液经121℃高压蒸汽灭菌处理后,水蓼液对3种细菌的抑制作用有所增强,火炭母液则对金黄色葡萄球菌的抑制作用有所增强。2种水煎煮液对3种细菌均有不同程度的抑制作用,可考虑以其为原料进行植物源抗菌剂的开发,拓宽其应用领域。     

Callus Induction from Insect Galls by Dryocosmus kuriphilus on Chestnut Tree

Dehydrodicaffeic acid dilactone (DDACD) was found in a cultured mushroom by screening for catechol-O-methyltransferase inhibitors. The enzyme which converts two molecules of caffeic acid to DDCAD has been extracted from the mushroom and purified and the enzyme reaction has been studied. It was markedly inhibited by reducing agents, such as NADPH, NADH, glutathione and ascorbic acid but stimulated by Fe³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cu⁺ and Zn²⁺ ions. Sodium diethyldithiocarbamate and sodium cyanide known to be copper chelating agents inactivated the enzyme, but activity was restored by addition of Cu²⁺ or Cu⁺. Although the enzymic reaction did not occur under anaerobic conditions, ¹⁸O-oxygen was not incorporated into DDCAD. o-Diphenol oxidase catalyzed DDCAD formation from caffeic acid and the DDCAD-forming enzyme catalyzed the formation of DOPAchrome from DOPA. Thus, the DDCAD-forming enzyme is a type of o-diphenol oxidase. Peroxidase and hydrogen peroxide produced DDCAD from caffeic acid.

On the other hand, DDCAD was non-enzymatically synthesized from caffeic acid in the presence of CuCl₂ in 64% yield. In both enzymic and non-enzymic syntheses, both (+)- DDCAD and (?)-DDCAD were produced.     

Isolation and characterization of microsatellite loci in Coccoloba cereifera (Polygonaceae), an endangered species endemic to the Serra do Cipó, Brazil

Microsatellite primers were isolated from the microendemic and threatened species Coccoloba cereifera, a shrub known only from a small region in the Serra do Cipó, Brazil. Thirteen primer pairs amplifying perfect and imperfect microsatellite regions were tested in 40 individuals from the one known occurrence of the species. Number of alleles ranged from two to six and levels of observed heterozygosities ranged from 0.21 to 0.95. These markers will be useful for the analysis of questions concerning population genetic structure and will assist in providing information for future conservation management programmes.