神农香菊化学成分及药理作用研究进展

介绍了神农香菊主要化学成分的研究成果,比较了花、茎、全草和叶等不同组织中主要活性成分的异同,并综述了其抑菌能力、抗氧化能力以及药用价值的最新研究进展。     

丁香的特征特性与栽培技术

阐述了丁香的特征特性,通过介绍丁香繁殖方法及其栽培技术,以期为丁香的栽培提供技术支持。     

Structure–activity relationships of eugenol derivatives against Aedes aegypti (Diptera: Culicidae) larvae

BACKGROUND: Dengue fever is a severe public health problem for several countries. In order to find effective larvicides to aid control programs, the structure‐activity relationships of eugenol derivatives against Aedes aegypti (Diptera: Culicidae) larvae were evaluated. Additionally, the composition and larvicidal activity of Syzygium aromaticum essential oil was assessed. RESULTS: Four compounds representing 99.05% of S. aromaticum essential oil have been identified. The essential oil was active against Ae. aegypti larvae (LC₅₀ = 62.3 and 77.0 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity of eugenol, the major compound of the essential oil, was further evaluated (LC₅₀ = 93.3 and 71.9 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity and structure‐activity relationships of synthetic derivatives of eugenol were also assessed. The larvicidal activity of the derivatives varied between 62.3 and 1614.9 ppm. Oxidation of eugenol allylic bond to a primary alcohol and removal of the phenolic proton resulted in decreased potency. However, oxidation of the same double bond in 1‐benzoate‐2‐methoxy‐4‐(2‐propen‐1‐yl)‐phenol resulted in increased potency. CONCLUSION: Structural characteristics were identified that may contribute to the understanding of the larvicidal activity of phenylpropanoids. The present approach may help future work in the search for larvicidal compounds. Copyright © 2012 Society of Chemical Industry     

UV–B辐射对神农香菊叶片表皮毛及其分泌物的影响

以神农香菊(Dendranthema indicum var.aromaticum)为材料,用紫外光UV–B对其进行辐射处理,处理时间分别为0(CK)、1、3、5、7 d,研究其对叶片表皮毛形态、密度和叶片表面分泌物的影响。结果表明:UV–B处理后的头状腺毛中部出现不规则凹陷,甚至扭曲;"T"形非腺毛出现顶细胞破裂、脱落现象;头状腺毛和"T"形非腺毛的密度均随处理天数的增加,呈先增加后减少的趋势,两者均在处理1 d时达最大,此时叶尖、叶中、叶基的头状腺毛密度每视野分别为16.00、13.67、18.67根,叶片下表皮的"T"形非腺毛密度每视野达43.84根;叶片表面分泌物中α–蒎烯、α–荜澄茄油烯的相对含量变化不明显,而杜松萜烯、1–石竹烯的相对含量变化较大,均在处理3 d时相对含量达到最高,分别为19.45%和14.71%;樟脑类物质和醇酮类物质的相对含量呈现先升高后降低的变化趋势,在第1天或第3天达到最大值,第7天降到最低。     

Toxicity nanoinsecticide based on clove essential oil against Tribolium castaneum (Herbst)

This study aimed to characterize nanoparticles loaded with clove (Syzygium aromaticum) essential oil-based polyethylene glycol (PEG) and to know their insecticidal activity against red flour beetle (Tribolium castaneum). The nanoparticles have irregular shapes in good dispersion. The nanoformulation could not enhance clove oil contact toxicity to T. castaneum, but could protect the oil from degradation and evaporation while simultaneously allowing sustained release, as indicated by the continued high toxicity for 16 weeks of storage.     

淹水胁迫对3种丁香生理指标的影响

在盆栽条件下研究了淹水胁迫对紫丁香、暴马丁香和小叶丁香生理生化特性的影响。结果表明,淹水胁迫使3种丁香的SOD、POD活性均有一定的增加,MDA含量和相对电导率大幅增长,叶绿素含量降低。通过各项指标的对比,发现紫丁香的抗淹水能力最弱,相对抗淹水能力较强的为小叶丁香。     

黄土丘陵区典型人工幼林土壤水分特征

为明确黄土丘陵区典型人工幼林土壤水分时空变化特征,采用ECH₂O土壤水分监测系统,基于标准径流小区坡面土壤水分观测方法,收集土壤水分及气象数据,分析了撂荒地与不同类型人工幼林土壤水分状况及时间稳定性。结果表明：(1)与撂荒地相比,人工幼林土壤含水量整体较低,且具有明显的季节性变化特征,变化趋势基本一致,均随降水量的增加(减少)而升高(降低);(2)不同类型人工林土壤水分垂直分布差异较大,相较于撂荒地,刺槐和油松在50 cm深度土层土壤含水量较低,在80—120 cm深度土层土壤含水量较高,丁香幼林土壤水分整体偏低;(3)油松和撂荒地土壤水分代表深度分别为：120 cm和80 cm,决定系数(R²≥0.9)和纳什系数(NSE≥-0.1)对该结果的评价显示土壤水分代表深度的选择均是可接受的,刺槐和丁香不同深度土层土壤水分差异较大。研究认为,在黄土丘陵区,人工幼林显著影响土壤水分垂直分布规律,土壤含水量整体呈低态势,相较于撂荒地,刺槐和丁香土壤水分变异性较大,油松较为稳定。     

北京松山不同密度丁香天然林枯落物及土壤水文效应

以北京松山5个不同密度（784,1 024,1 210,1 616,1 872株/hm²）的丁香（Syzygium aromaticum）天然林为对象,对其枯落物层及土壤层水文效应进行研究。结果表明:枯落物总蓄积量、最大持水率、最大持水量随丁香天然林密度的升高而增大。枯落物的总储量在13.19～31.66 t/hm²之间;有效拦蓄能力在32.71～79.77 t/hm²之间;枯落物最大持水量在50.76～119.29 t/hm²之间,与浸泡时间呈明显的对数关系（R > 0.86）;枯落物最大持水率为385.72%～507.16%,枯落物吸水速率与浸泡时间呈明显的幂函数关系（R > 0.99）;同一密度土壤容重随土层深度的增加而增大,总孔隙度随密度的升高先增大后减小。初渗速率在37.50～54.55 mm/min之间,入渗速率与入渗时间存在较好的幂函数关系（R > 0.99）。中密度丁香天然林水源涵养功能较强。     

不同激素处理对丁香扦插生根的影响

采用IBA,ABT,NAA对丁香插穗进行处理,分析不同激素对丁香扦插生根特性的影响。结果表明,IBA处理硬枝插穗生根特性效果最佳,生根率最大值达到了84.63%;NAA处理嫩枝插穗生根效果最好,生根率最大值达93.32%。       

静态顶空气相-质谱联用法分析神农香菊花蕾和花中的挥发性成分

利用顶空加热收集神农香菊花蕾和花的挥发性成分,运用GC-MS分离和鉴定挥发性成分的结构及相对含量。结果显示两个花期阶段共鉴定出52种挥发性成分,花蕾含44种,花中含47种,神农香菊由花蕾发展到花时,其主要成分α-水芹烯的含量明显降低,而对伞花烃的含量显著增高。α-水芹烯可能经过生理变化转化为对伞花烃,这为进一步研究神农香菊的挥发性成分提供了参考.