Three new bibenzyl derivatives from Dendrobium nobile

Three new bibenzyl derivatives have been isolated from the stems of Dendrobium nobile Lindl. (Orchidaceae). Their structures were established as 4,5-dihydroxy-3,3′,α-trimethoxybibenzyl (1), 4,4′-dihydroxy-3,3′,5,α-tetramethoxybibenzyl (2) and 4-hydroxy-3,3′,4′,5,α-pentamethoxybibenzyl (3) on the basis of spectroscopic analysis.     

Three new bibenzyl derivatives from Dendrobium nobile

Three new bibenzyl derivatives have been isolated from the stems of Dendrobium nobile Lindl. (Orchidaceae). Their structures were established as 4,5-dihydroxy-3,3',alpha-trimethoxybibenzyl (1), 4,4'-dihydroxy-3,3',5,alpha-tetramethoxybibenzyl (2) and 4-hydroxy-3,3',4',5,alpha-pentamethoxybibenzyl (3) on the basis of spectroscopic analysis.     

Two new dendrocandins with neurite outgrowth-promoting activity from Dendrobium officinale

Two new bibenzyl derivatives, dendrocandin T (1) and dendrocandin U (2), together with eight known bibenzyls, were isolated from the stems of Dendrobium officinale. Those compounds were sent for the first time for central nervous system-related bioassay and the results indicated that compounds 3, 4, and 5 have a certain degree of neurite outgrowth-promoting activity, and compounds 1, 2, 6, and 7 also have weak activity. The results indicated that D. officinale used as health food and traditional Chinese medicine “Tiepi Shihu” has a health function of neurotrophic effects.     

铁皮石斛化学成分及药理作用研究进展

铁皮石斛是名贵的中草药之一。其含有多糖、芪类、生物碱、氨基酸和微量元素等多种成分,具有增强免疫、抗氧化、抗肿瘤、抗疲劳、降血糖和养阴生津等多种生物活性。本文综述了铁皮石斛化成分和药理学研究进展。     

正交试验优选铁皮石斛类原球茎多糖的提取纯化工艺

目的:优选铁皮石斛类原球茎多糖提取纯化工艺。方法:采用正交试验,以多糖含量为评价指标,以液固比、浸提时间、提取次数为考察因素优选提取工艺;以样品溶液与Sevage试剂体积比、氯仿与正丁醇的体积比、反应时间为考察因素优选纯化工艺。结果:多糖最佳提取纯化工艺为80℃热水浸提多糖,液固比为20倍,提取时间2h,提取次数3次,80%乙醇沉淀,样品溶液与Sevage试剂体积比为4∶1,氯仿与正丁醇的体积比为5∶2,反应时间为5min。结论:所建方法简便、可靠、重现性好,可供本品质量控制。     

A new phenanthrene dimer from Dendrobium palpebrae

A new phenanthrene dimer, namely dendropalpebrone (1), was isolated from the whole plant of Dendrobium palpebre, along with nine known compounds (2–10). All of the isolates were evaluated for their hydroxyl radical scavenging effects using a deoxyribose assay. Dendroflorin (10) showed an appreciable activity, and therefore was selected for further studied in RAW264.7 cells. Compound 10 significantly decreased ROS in H₂O₂-stimulated RAW264.7 cells in a dose-dependent manner, and improved activity of SOD, GPx, and CAT enzymes.     

铁皮石斛胚状体对大鼠抗疲劳能力的影响

目的研究铁皮石斛胚状体对大鼠抗疲劳能力的影响。方法大鼠随机分为低、中、高剂量组（铁皮石斛胚状体0．2、0．4、0．8g／kg）,空白对照组、跑步对照组及铁皮枫斗组（铁皮枫斗1．2g／kg）,进行大鼠跑台实验。观察大鼠运动前、运动后0min及运动后30min血糖含量、全血乳酸含量变化并检测运动后肝糖元、肌糖元及血尿素氮的含量。结果与跑步对照组相比,铁皮石斛胚状体各剂量组可以在跑步30min后提高血糖含量并降低全血乳酸含量,中、高剂量组可以降低运动后肝糖元及肌糖元的消耗,各剂量组均能明显降低血尿素氮的含量。结论铁皮石斛胚状体具有提高大鼠抗疲劳能力的作用。     

A new phenanthrenequinone from Dendrobium draconis

A number of Dendrobium species (Orchidaceae) have been used as health foods. In Thailand, the tea prepared from the stems of Dendrobium draconis Rchb.f. (Orchidaceae) has been used as a blood tonic. Our phytochemical investigation of this plant led to the isolation of a new compound namely 5-methoxy-7-hydroxy-9,10-dihydro-1,4-phenanthrenequinone (1), along with four known stilbenoids including hircinol (2), gigantol (3), batatasin III (4), and 7-methoxy-9,10-dihydrophenanthrene-2,4,5-triol (5). The structures of these compounds were determined through extensive spectroscopic studies, including ¹H and ¹³C NMR, DEPT, COSY, NOESY, HMQC, HMBC, ESI-MS, and HR-ESI-MS experiments. In the DPPH-free radical assay, these stilbene derivatives showed appreciable antioxidant activity.     

Chemical constituents from Dendrobium hainanense

A new phenolic derivative (1) and a new dihydrophenanthrene (2) were isolated from the aerial part of Dendrobium hainanense rofe, along with 12 known compounds. The structures of the new compounds were elucidated by spectroscopic analysis，and the relative configuration of compound 1 was determined by J-based configuration analysis (JBCA) method. Bioassay result indicated that compound 1 exhibited weak antibacterial activity against Canidia albicans and Ralstonia solanaceanum.     

石斛多糖抗氧化活性研究

目的研究石斛多糖的体内、体外抗氧化活性。方法①体外抗氧化实验：用化学反应法检测石斛多糖对邻苯三酚自氧化反应产生的超氧阴离子和Fenton反应产生的羟自由基的清除作用;②体内抗氧化实验：昆明种小鼠随机分为空白对照组、小剂量组、中剂量组和大剂量组,每组10只。研究石斛多糖对小鼠血清及肝组织中SOD、GSH-Px、MDA的影响。结果石斛多糖具有清除羟基自由基和超氧阴离子自由基的作用,可显著提高小鼠血清和肝组织中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活力,降低丙二醛（MDA）含量。结论石斛多糖具有明显的抗氧化活性,为进一步开发石斛药材提供依据。     

A new picrotoxane-type sesquiterpene from Dendrobium findlayanum

A new picrotoxane-type sesquiterpene, findlayanin (1), was isolated from Dendrobium findlayanum with crystallinin (2). The structure of compound 1 was established to be (1R,2S,3R,4S,5R,6S,9R)-2,3,11,12-tetrahydroxypicrotoxan-12(15)-lactone by spectroscopic methods.     

Two new picrotoxane-type sesquiterpenoid lactones from Dendrobium williamsonii

Two new picrotoxane-type sesquiterpenoid lactones, dendrowillins A (1) and B (2), together with five known sesquiterpenoids, (?)-picrotin (3), α-dihydropicrotoxinin (4), dendronobilin B (5), amoenin (6), and (?)-10β,13,14-trihydroxyalloaromadendrane (7), were isolated from the whole plants of Dendrobium williamsonii. Their structures were elucidated by means of extensive spectroscopic analysis.     

Dihydroayapin, a new coumarin compound from Dendrobium densiflorum

A new coumarin named dihydroayapin (1) together with seven known compounds were isolated from the stems of Dendrobium densiflorum. On the basis of physicochemical and spectral evidences, the structure of 1 was established as 6,7-methylenedioxy-3,4-dihydrobenzopyran-2-one.     

鲜铁皮石斛提取物抗Lewis肺癌的机制研究

目的考察鲜铁皮石斛生物碱、多糖提取物对小鼠Lewis肺癌的抑制作用,并探讨其作用机制。方法制备Lewis肺癌实体瘤小鼠模型,将80只实体瘤模型小鼠均分为模型组、环磷酰胺（CTX）组、鲜铁皮石斛生物碱提取物高、中、低剂量（20,10,5g·kg^-1）组、鲜铁皮石斛多糖提取物高、中、低剂量（20,10,5g·kg^-1）组。除CTX组在开始给药后第3,6,9天腹腔注射CTX（40mg·kg^-1）外,其余各组连续给药20d。观察鲜铁皮石斛生物碱、多糖提取物对荷瘤小鼠瘤重、脾脏指数、血清中白细胞介素－2（interleukin－2,IL－2）和肿瘤坏死因子-α（TNF-α）水平的影响。结果鲜铁皮石斛生物碱、多糖各剂量组的瘤体重量均低于模型组,多糖高剂量组,生物碱高、中剂量组抑制瘤重效果显著（P＜0．05）;鲜铁皮石斛生物碱、多糖各剂量组的脾脏重量、脾脏指数均高于模型组,多糖高、中剂量组效果最好（P＜0．05）;不同剂量生物碱和多糖组均能提高TNF-α、IL-2水平,生物碱高剂量组,多糖高、中剂量组提高效果显著（P＜0．05）。结论鲜铁皮石斛生物碱、多糖提取物对Lewis肺癌荷瘤小鼠肿瘤有明显的抑制作用,其作用机制可能与提高脾脏指数,调节血清中TNF-α、IL-2水平有关。     

Five new compounds from Dendrobium crystallinum

Five new compounds, dencryol A (1), dencryol B (2), crystalltone (3), crystallinin (4), and 3-hydroxy-2-methoxy-5,6-dimethylbenzoic acid (5), together with six known compounds, dendronobilin B (6), syringic acid (7), apigenin (8), isoviolanthin (9), 6?-glucosyl-vitexin (10), and palmarumycin JC2 (11), have been isolated from the stems of Dendrobium crystallinum, of which compounds 9–11 were isolated from the genus Dendrobium for the first time, and all the other compounds were first obtained from this plant. Their structures were established on the basis of spectroscopic analysis and literature data.     

金钗石斛中的菲类和木脂素类成分及其抗氧化作用

研究金钗石斛茎中的抗氧化活性成分，并探讨它们的构效关系。综合运用现代色谱学和光谱学方法对金钗石斛60％乙醇提取物中的化学成分进行分离鉴定，采用DPPH自由基清除法评价化合物的抗氧化活性。从金钗石斛的活性部位中分离得到5个菲类化合物和4个木脂素类化合物，它们的结构鉴定为流苏菲（1），毛兰菲（2），4-甲氧基菲-2，7-二醇（3），2,5-二羟基-4，9-二甲氧基菲（4），3，7-二羟基-2，4-二甲氧基菲（5），丁香脂素（6），松脂素（7），5′-甲氧基松脂素（8），鹅掌揪树脂醇-A（9）。化合物2和6对DPPH自由基清除活性强于Vc；化合物3，4，5，7，8和9的活性弱于Vc，但强于BHT。所有化合物均为首次报道从金钗石斛中分离得到，化合物3，4和9为首次报道从石斛属植物中分离得到。在DPPH自由基清除法中，酚羟基的邻位存在具有供电作用的甲氧基时对菲类和木脂素类化合物的抗氧化活性具有积极的作用。     

长穗桑中的苯并呋喃类化合物

为了研究长穗桑中具有抗氧化活性的化学成分，采用硅胶、Sephadex LH-20、RP-C18等色谱方法从长穗桑茎皮的95%乙醇提取物中分离得到7个苯并呋喃类化合物：wittifuran D (1)、 wittifuran E (2)、 moracin C (3)、 moracin M (4)、 moracin P (5)、 2-(3,5-dihydroxyphenyl)-5,6-dihydroxybenzofuran (6)和mulberroside C (7)，并通过NMR、MS等波谱分析手段鉴定了化合物的结构。化合物1～7均为首次从该种植物中分离得到，其中化合物1和2为新化合物。对化合物3～7进行了抗氧化活性筛选，其中化合物3、4、6浓度在1×10^-5 mol·L^-1时对Fe²⁺-半胱氨酸诱导的肝微粒体脂质过氧化产生的丙二醛(malondialdehyde，MDA)的抑制率分别为73%、69%和89%。     

Synthesis and antimicrobial activity of new adamantane derivatives III

Some novel ester imides synthesised from trimellitic acid anhydride and 1-adamantanol or 2-adamantanol, were tested as antimicrobial compounds. Unfortunately, these agents showed a modest antibacterial activity (MIC > 6 microg/ml). However, a comparison of these N-substituted adamantylester imides with the series published previously, indicated that the incorporation of L-alanine and L-phenylalanine into the phthalimide moiety was the best choice regardless of the series and leads to antimicrobial activity against Staphylococcus aureus strains.     

New tetralone derivatives from the leaves of Cyclocarya paliurus

Two new tetralone derivatives, named cyclopalosides A (1) and B (2), were isolated from the leaves of Cyclocarya paliurus by column chromatography on silica gel, reversed-phase C₁₈ silica gel and preparative HPLC. Their chemical structures were established on the basis of extensive analyses of spectroscopic data. Their structural characteristic is tetralone glycoside with a caffeoyl unit. The antioxidant activities of compound 1 were evaluated by using hydroxyl, superoxide anion, and DPPH radical scavenging assay.