New Thymol Derivatives and Cytotoxic Constituents from the Root of Eupatorium cannabinum ssp. asiaticum

Two new thymol (=5‐methyl‐2‐(1‐methylethyl)phenol) derivatives, 8,10‐didehydro‐9‐(3‐methylbutanoyl)thymol 3‐O‐tiglate ( 1 ) and 9‐O‐angeloyl‐8‐methoxythymol 3‐O‐isobutyrate ( 2 ), were isolated from the root of Eupatorium cannabinum ssp. asiaticum, together with six known compounds, 3 – 8 . The structures of 1 and 2 were determined through extensive 1D/2D‐NMR and MS analyses. Among the isolates, 9‐acetoxy‐8,10‐epoxythymol 3‐O‐tiglate ( 3 ) was the most cytotoxic, with IC₅₀ values of 0.02±0.01, 1.02±0.07, and 1.36±0.12 μg/ml, respectively, against DLD‐1, CCRF‐CEM, and HL‐60 cell lines. In addition, 10‐acetoxy‐9‐O‐angeloyl‐8‐hydroxythymol ( 4 ) and eupatobenzofuran ( 6 ) exhibited cytotoxicities, with IC₅₀ values of 1.14±0.16 and 2.63±0.22, and 7.63±0.94 and 2.31±0.14 μg/ml, respectively, against DLD‐1 and CCRF‐CEM cell lines.     

紫茎泽兰9-羰基-10,11-去氢泽兰酮分布积累动态

9-羰基-10,11-去氢泽兰酮为紫茎泽兰（Eupatorium adenophorum）的主要致肝脏毒性成分及杀虫的生物活性成分。从紫茎泽兰叶片中分离提纯得到9-羰基-10,11-去氢泽兰酮（Euptox A）标准品,建立了高效液相色谱法测定紫茎泽兰中Euptox A含量的分析方法。采用C18反相色谱柱,柱温30°C,以甲醇-水（60：40,v/v）为流动相、流速为0.8 mL.min–1、检测波长为255 nm进行测定。Euptox A在紫茎泽兰中的添加回收率为97.3%–103.7%,检测限为0.4μg.g–1。利用建立的方法测定Euptox A在紫茎泽兰体内分布与积累的动态变化规律。结果表明,Euptox A主要分布在紫茎泽兰的叶片中,且在营养生长期积累量高,生殖生长期积累量低。该方法快速、简捷,可用于紫茎泽兰原料及其产品中Euptox A成分的测定。     

紫茎泽兰对四环素的吸收特性

[目的] 探究四环素在水和紫茎泽兰间的传递以及在紫茎泽兰体内的累积特征。[方法] 利用高效液相色谱检测紫茎泽兰幼苗在水培过程中对四环素的吸收及其在根茎叶中的积累。[结果] 在10~20 mg·L^-1四环素的处理浓度范围内,紫茎泽兰根、茎、叶均能吸收并积累四环素,且吸收累积量均随处理浓度和处理时间的增加而升高。当紫茎泽兰在20 mg·L^-1四环素的水培液处理20 d时,茎中的四环素累积量最高,为（59.34±3.86）mg·kg^-1;根中的次之,为（52.52±5.89）mg·kg^-1;而叶中的最低,为（23.19±4.17）mg·kg^-1。此外,紫茎泽兰茎的四环素富集系数最大,根的次之,叶的最小。[结论] 紫茎泽兰能够较好地从水培液中吸收并累积四环素,具有吸收净化四环素污染水源的潜力。     

中国两种新归化植物——巴尔干大戟和假蒿

报道在云南发现的新归化植物,分别是大戟科巴尔干大戟(Euphorbia oblongata Griseb.)和菊科假蒿[Eupatorium capillifolium (Lam.) Small ex Porter&Britton],凭证标本均保存于云南大学植物标本馆(YUKU)。巴尔干大戟原产于欧洲南部和西亚,现发现归化于云南省昆明市呈贡区;巴尔干大戟的主要鉴别特征是幼茎和花序轴密被白色长柔毛,蒴果球形,有瘤状突起,无毛。假蒿原产于美国南部,是园艺上广泛栽培的物种,现发现其在云南省大理州剑川县逸野归化;假蒿的主要鉴别特征是植株被柔毛,叶片近长卵形,2至3回羽状全裂,小裂片线形或长圆形,头状花序排成复总状,每个头状花序有小花5,花冠白色微绿。文中描述巴尔干大戟和假蒿的形态特征,并提供两种的野外生态照片;此外,对其可能的传入途径进行分析,简要评估入侵风险与危害。     

Inhibitory effects of leachate from Eupatorium adenophorum on germination and growth of Amaranthus retroflexus and Chenopodium glaucum

Amaranthus retroflexus L. and Chenopodium glaucum L. are two widely distributed destructive weeds. Their strong adaptability and massive seed production make them the hardest weeds to deal with. This present study intended to investigate the effect of leachate from Eupatorium adenophorum on the growth of these weeds and explore the potential to develop an environmental friendly strategy to use the leachate to control the weeds. Seeds of A. retroflexus L. and C. glaucum L. were soaked in solutions containing 0%, 0.6%, 1.25%, 2.5%, and 5% leachate from E. adenophorum leaves. A. retroflexus and C. glaucum seedlings grown in pots were sprayed with leachate solutions in the same concentration range. The effects of these leachate solutions on membrane permeability and germination of seeds, and growth and physiological characteristics of the seedlings were investigated. The highest concentration of leachate (5%) caused significant damage to the cell membrane of seeds of both weed species, whereas lower concentrations (0.6%) promoted repair of the membrane system, as reflected by higher and lower than control in relative conductivity (RC), respectively. Different concentrations of leachate showed distinct allelopathic inhibitory effects on the two weed species; lower concentrations showed weak inhibitory or even positive effects, whereas higher concentrations showed stronger inhibitory effects. Higher concentrations of leachate (2.5% and 5%) delayed germination and significantly decreased the emergence rate of the seeds, survival rate, and dry matter accumulation of the seedlings. When treated by 5% leachate, the emergence date of A. retroflexus was delayed by 3.6 d, emergence rate of the seeds and survival rate was 69.1% and 70.6% of the control, respectively, seedling dry matter was 48.6% less than the control; In the case of C. glaucum, the emergence date was delayed by 2.7 d, emergence rate of the seeds and survival rate was 45.1% and 58.6% of the control, respectively, seedling dry matter was 44.7% less than the control. There were significant interactions among the different concentrations of leachate and the length of treatment period with respect to activities of antioxidant enzymes, malondialdehyde (MDA) contents, and chlorophyll contents. Seedlings treated with 0.6%, 1.25%, or 2.5% leachate solution for 24–72 h showed increased superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. When seedlings were treated with leachate solutions for 96 h, antioxidant enzyme activities and chlorophyll content decreased in A. retroflexus, but only CAT activity decreased in C. glaucum. When seedlings of the two weed species were treated with 5% leachate solution, CAT activity and chlorophyll content decreased and MDA content gradually increased with longer treatment times (from 24 to 96 h). The two weed species showed different allelopathic responses to E. adenophorum; A. retroflexus was more sensitive than C. glaucum. Based on the investigation, it could be speculated that the delayed germination and low germination rate of the weeds after treatment by leachate could be due to the fact that leachate damaged the membrane system of the seeds. By delaying germination, lowering the germination rate of the weeds and inhibiting seedling growth, leachate from E. adenophorum could provide an effective way of controlling the weeds.     

不同地理种源紫茎泽兰的生态适应性比较

采用交互移植法,对移栽在6种不同生境中的5个不同种源紫茎泽兰幼苗的存活率、株高、分枝数、生物量、单株花序数、产种量和种子萌发率进行了为期1年的对比研究.结果表明：各种源紫茎泽兰的幼苗生长和繁殖特性对样地环境条件变化均表现出很强的可塑性.试验样地因素对幼苗株高、分枝数、生物量、单株花序数和产种量的影响均达到极显著水平(P＜0.001).随着样地纬度和海拔的升高,各种源的幼苗株高、分枝数量、单株生物量、每株花序数量和单株产种量均呈下降趋势,且各样地间的差异均达到显著水平(P＜0.05).但种源因素对幼苗株高、分枝数、生物量、单株花序数和产种量的影响均不显著（P＞0.05）.除单株产种量外,种源与试验样地的交互作用对上述各指标的影响均不显著.在各样地内,当地种源幼苗的存活率、生长能力和繁殖能力均未表现出显著的优势.说明紫茎泽兰在我国西南地区入侵成功主要依靠其较高的表型可塑性,而局域适应的作用相对较小.     

贵州水银洞金矿紫茎泽兰重金属元素测定与分析

利用原子吸收法对贵州水银洞金矿紫茎泽兰及其基质中Cr、Pb、Zn、Cd、Hg和As含量进行了测定和分析。结果表明,贵州水银洞金矿废水处理区土壤Hg(12.575 mg·kg^-1)和As(501.374 mg·kg^-1)已严重超标,Hg和As的平均含量分别是国家土壤环境质量三级标准(GB15618-1995)的8.383倍和12.534倍,污染极为严重;紫茎泽兰对该矿区不同的重金属富集能力不同,尤其对该矿区Cr有较强的富集作用,具有一定的Cr污染修复潜力。紫茎泽兰对所测定的6种重金属元素的吸收转移能力有较大的差异,整个植株对Pb、Zn 和Cr具有很强的吸收转移能力。其茎、叶对不同的重金属元素的吸收转移能力也呈现出很大的差异,紫茎泽兰茎对Cr、Pb和Cd具有很强的吸收转移能力,而叶对Zn、Pb和Hg具有很强的吸收转移能力。除As外,紫茎泽兰对Cr、Pb、Zn、Cd和Hg都具有不同程度的耐受能力,对该矿区的生态恢复具有重要的作用。     

植物替代控制3种入侵杂草技术的研究与应用进展

植物替代控制是利用一种或多种植物的生长优势控制入侵杂草的方法,它是控制外来杂草危害的有效途径之一;因其既可控制入侵杂草危害又能取得一定的经济效益及生态效益而被人们广泛接受。本文简要介绍了我国3种入侵杂草植物替代控制技术研究与应用现状,系统总结了植物替代控制技术阻截和修复豚草、紫茎泽兰及黄顶菊扩散危害的技术模式和效果,提出了植物替代控制技术未来研究的方向和重点。     

Ecological application of biotic resistance to control the invasion of an invasive plant,Ageratina altissima

Biotic resistance is the ability of species in a community to limit the invasion of other species. However, biotic resistance is not widely used to control invasive plants. Experimental, functional, and modeling approaches were combined to investigate the processes of invasion by Ageratina altissima (white snakeroot), a model invasive species in South Korea. We hypothesized that (1) functional group identity would be a good predictor of biotic resistance to A. altissima, whereas a species identity effect would be redundant within a functional group, and (2) mixtures of species would be more resistant to invasion than monocultures. We classified 37 species of native plants into three functional groups based on seven functional traits. The classification of functional groups was based primarily on differences in life longevity and woodiness. A competition experiment was conducted based on an additive competition design with A. altissima and monocultures or mixtures of resident plants. As an indicator of biotic resistance, we calculated a relative competition index (RCI_avg) based on the average performance of A. altissima in a competition treatment compared with that of the control where only seeds of A. altissima were sown. To further explain the effect of diversity, we tested several diversity–interaction models. In monoculture treatments, RCI_avg of resident plants was significantly different among functional groups but not within each functional group. Fast‐growing annuals (FG1) had the highest RCI_avg, suggesting priority effects (niche pre‐emption). RCI_avg of resident plants was significantly greater in a mixture than in a monoculture. According to the diversity–interaction models, species interaction patterns in mixtures were best described by interactions between functional groups, which implied niche partitioning. Functional group identity and diversity of resident plant communities were good indicators of biotic resistance to invasion by introduced A. altissima, with the underlying mechanisms likely niche pre‐emption and niche partitioning. This method has most potential in assisted restoration contexts, where there is a desire to reintroduce natives or boost their population size due to some previous level of degradation.