稀土微肥对铁皮石斛试管苗壮苗的影响

目的研究稀土微肥对铁皮石斛试管苗壮苗的影响。方法通过正交试验,以石斛小苗为外植体,培养在附加了3种不同稀土元素组合的1/2MS 20%的香蕉提取物的培养基上进行培养。结果3种稀土元素中的镧(La)对试管苗增质量、叶绿素b、总叶绿素和石斛多糖的量都有显著的影响;3种稀土元素都对试管苗的叶片数、根数、分蘖数以及叶绿素a的量影响不显著。结论为铁皮石斛试管苗的壮苗以及品质的提高提供了科学的依据。     

金钗石斛的研究进展

金钗石斛是常用中药,为兰科(Orchidaceae)石斛属(Dendrobium Sw.)植物金钗石斛(D.nobile Lindl.)的新鲜或干燥茎,其化学成分类型主要有生物碱类、酚类、多糖类等,其中生物碱类为主要成分;药理作用主要有抗肿瘤、抗衰老、增强机体免疫力、抗白内障和抗菌等作用.对其化学成分、药理作用及临床应用情况进行分类总结,为金钗石斛的进一步研究开发提供依据.     

铁皮石斛试管培养物多糖含量测定

目的:比较铁皮石斛试管培养物与原药材的多糖含量.方法:用比色法测定石斛多糖的含量.结果:铁皮石斛原药材含多糖量最高,其次是原球茎和试管苗.结论:铁皮石斛原球茎多糖含量比试管苗多糖含量高.     

球花石斛茎中香豆素类成分的定位与相对定量

目的探讨不同生长年限、不同部位球花石斛 (Dendrobium thyrsiflorum Rchb. f.)茎中香豆素类(coumarins)成分的分布与相对含量变化，为合理评价及利用药用石斛提供科学依据。方法利用激光共聚焦显微技术(laser scanning confocal microscopy, LSCM)观察二月份采收的球花石斛1-3龄茎的基部、中部和顶部的香豆素类成分。所记录数据经正态性、方差齐性检验后进行方差分析(ANOVA)，并使用Tukey′s检验作多重比较。结果 香豆素类成分主要分布在球花石斛茎的维管束部位并以维管束外侧纤维的壁较多。统计分析显示香豆素类成分的含量在不同年龄茎的各个部位之间差异极显著或显著，显著值分别为：基部P=0.004(<0.01)；中部P=0.009(<0.01)；顶部P=0.036(<0.05)。结论若以利用香豆素类成分为目的，建议二月采收时，宜选择2龄茎。     

Eight new bibenzyl derivatives from Dendrobium candidum

Eight bibenzyl derivatives, namely dendrocandins J–Q (1–8), were isolated from the stems of Dendrobium candidum. Their structures were elucidated by 1D and 2D NMR experiments and mass spectrometry. Compounds 1–8 were examined for antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay, and the IC₅₀ values were 36.8, 70.2, 45.0, 60.5, 87.6, 50.4, 22.3, and 30.3 μM, respectively.     

Antimicrobial activity in medicinal plants of the Scrophulariaceae and Acanthaceae

One hundred and one crude extracts obtained from various plant parts of 59 species representing mostly the plant families Scrophulariaceae and Acanthaceae have been investigated for their antimicrobial activity. Plants were selected using ethnobotanical and chemotaxonomic information. Growth inhibition using agar disk diffusion assays was determined against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Growth inhibitory activity against one or more of the microbial species was detected in over 40% of the samples.     

铁皮石斛茶缓解小鼠体力疲劳作用的研究

目的研究铁皮石斛茶对小鼠的抗疲劳保健功能。方法给小鼠灌胃给药设低、中、高3个剂量组,同时设立对照组,观察小鼠负重游泳时间、肝糖原含量、血乳酸、尿素等指标的变化。结果铁皮石斛茶能明显延长小鼠负重游泳时间,显著增加小鼠肝糖原含量,减少小鼠运动前后血乳酸曲线下面积。结论铁皮石斛茶具有缓解体力疲劳功能。     

铁皮石斛多糖对高糖诱导的血管内皮细胞Bax、Bcl-2表达的影响

目的优化铁皮石斛多糖提取工艺,研究其对高糖诱导的静脉血管内皮细胞(HUVEC)的保护作用机制。方法在单因素实验基础上,利用响应面法优化多糖的提取工艺;体外培养HUVEC细胞,将对数生长期的细胞分为空白对照组、正常血糖组、高糖刺激组和不同铁皮石斛多糖浓度+高糖刺激组,分别作用24和48 h后,采用MTT法检测的HUVEC凋亡的影响,用RT-PCR法检测内皮细胞Bax、Bcl-2的表达情况。结果铁皮石斛多糖提取的最优条件为:提取次数为2.8次,液(m L)料比(g)15.75∶1,提取时间2 h,在此条件下,理论计算提取率达到25.1%,实测提取率为24.9%,与模型高度拟合。与正常组相比,高糖组抑制细胞的生长,增强Bax的表达,抑制Bcl-2的表达,在高糖诱导下,铁皮石斛多糖促进细胞生长,抑制Bax的表达,增强Bcl-2的表达。结论通过响应面法优化的工艺,得率高,提取效果好。铁皮石斛多糖可通过抑制高糖诱导的血管内皮细胞Bax的表达,增强Bcl-2的表达,从而抑制血管内皮细胞凋亡,在一定程度上可防治糖尿病血管病变。     

铁皮石斛对2型糖尿病大鼠胰岛组织JNK、AKT蛋白磷酸化表达的影响

目的:研究铁皮石斛有效部位对2型糖尿病大鼠胰岛组织JNK蛋白、AKT蛋白磷酸化表达的影响。方法:采用正常大鼠、高脂高糖-链脲佐菌素致糖尿病(STZ-T2DM)模型,研究铁皮石斛降糖机制,Western blot法检测JNK、ph JNK、AKT、ph AKT在大鼠胰岛组织中的表达。结果:与正常对照组相比较,模型组大鼠胰岛组织JNK蛋白磷酸化程度显著增加(P<0.01),Aktser473磷酸化减弱(P<0.01)。与模型组相比较,铁皮石斛TP、TF、TE显著降低大鼠胰岛组织JNK(Thr183/Tyr185)磷酸化,增加Aktser473磷酸化水平。结论:铁皮石斛有效部位具有抑制T2DM大鼠胰岛组织JNK Thr183/Tyr185磷酸化水平,增加AKT ser473磷酸化水平的作用。     

Chemical composition of essential oil and oleoresins of Zingiber officinale and toxicity of extracts/essential oil against diamondback moth (Plutella xylostella)

Abstract

Essential oil (EO) of ginger and oleoresins isolated from extraction solvents by GC–MS. Zingiberene was the major constituent in all the samples, and ethanol could extract the maximum quantity (21.2%) from the dried de-oiled cake (EDD) followed by EO (20.3%) as compared to oleoresins. Hydro-distilled EO contains higher oxygenated monoterpenes (22.4%) than oleoresins. EDD showed more toxicity to larvae of Plutella xylostella (LC₅₀?=?4957.9?mg L^?1) after 96?h and was followed by EDW (LC₅₀?=?5067.6?mg L^?1) and EF (LC₅₀?=?6631.2?mg L^?1). EO also showed promising efficacy (LC₅₀?=?5875.9?mg L^?1) and repellency (97.1%) against P. xylostella.