中药萝藦中C21甾苷的含量测定

[目的]测定萝藦中C21甾苷的含量。[方法]以孕甾烯醇酮为标准物,采用磺基醋酸汞试剂法于510 nm波长处测定C21甾苷的吸光度值,并计算其含量。[结果]萝藦中C21甾苷含量为0.003 3 mg/ml,与相关文献中萝藦科植物中甾苷的含量接近。[结论]该方法准确率、重现性、线性关系等都满足科研和生产要求,可以用于萝藦中C21甾苷的含量测定。     

拟南芥山奈酚糖苷对UV-B辐射的响应

以拟南芥(Arabidopsis thaliana)为材料,通过施加低强度(40μw·cm-2)和相对长时间(7 d)的UV-B辐射,研究拟南芥幼苗和成苗中三种山奈酚糖苷即山奈酚-3-O-鼠李葡萄糖基-7-O-鼠李糖苷(K1)、山奈酚-3-O-葡萄糖基-7-O-鼠李糖苷(K2)、山奈酚-3-O-鼠李糖基-7-O-鼠李糖苷(K3)含量及合成途径关键酶编码基因表达水平对UV-B辐射的响应.结果表明,拟南芥幼苗三种山奈酚糖苷含量均为成苗的10倍左右.经过7 d的UV-B辐射处理,拟南芥幼苗中山奈酚糖苷积累水平、合成途径关键酶编码基因chs和fls1的相对表达量均显著高于对照植株,山奈酚糖苷表现为响应UV-B辐射而积累.在拟南芥成苗和幼苗中三种山奈酚糖苷组合模式应对UV-B辐射的变化并不一致,这与其在防御机制中的不同角色有关     

山莓叶三萜对大鼠免疫功能的影响

为探明山莓叶三萜的免疫调节作用,腹腔注射环磷酰胺诱导大鼠免疫低下.将成模后大鼠分别连续灌服生理盐水和0.25、0.50、1.00 mg/mL山莓叶三萜精提物(以下简称模型对照组(CK2)、低浓度组、中浓度组和高浓度组),每天灌服1次,1 mL/次,连续15d.试验结果:各模型组大鼠的廓清指数和吞噬指数均随山莓叶三萜精提物浓度的升高呈上升趋势,但廓清指数各组间的差异不显著.中浓度组大鼠血清中的白细胞介素-2 (IL-2)含量显著低于CK2,高浓度组的极显著低于CK2.低浓度组大鼠血清中的IL-6含量低于CK2,但二者差异不显著;中浓度组和高浓度组均极显著低于低浓度组和CK2,高浓度组极显著低于除中浓度组外的其他模型组.结果表明,山莓叶三萜具有一定的免疫调节作用(山莓叶三萜提取物能提高大鼠巨噬细胞的吞噬能力;对大鼠IL-2、IL-6分泌具有抑制作用).     

Three new acetylated benzyl-beta-resorcylate glycosides from Cassia obtusifolia

Three new acetylated benzyl-beta-resorcylate glycosides (1-3) were isolated from seeds of Cassia obtusifolia. Their structures were determined on the basis of the spectroscopic methods and physicochemical properties as 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[2,6-O-diacetyl]-d-glucopyranoside (1), 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[3,6-O-diacetyl]-d-glucopyranoside (2) and 2-benzyl-4, 6-dihydroxy benzoic acid-6-O-[4,6-O-diacetyl]-d-glucopyranoside (3), respectively.     

Acylated flavonol glycosides from Epimedium elatum, a plant endemic to the Western Himalayas

Herba Epimedii is a well-known Botanical preparation used over long time in traditional Chinese medicine. The extracts and chemical constituents from Epimedium species are aphrodisiac as well as to treat many ailments. Chemical investigation of lonely species growing in Kashmir Himalaya Epimedium elatum was undertaken to evaluate its chemical profile. Two unusual substituted acylated flavonol glycosides named Elatoside A (1) and Elatoside B (2) have been isolated from the ethanolic extract of E. elatum along with 23 previously known ones (3-25). All isolates were evaluated for antimicrobial and PPAR-γ ligand binding activity, and some of them appeared to be modestly active.     

甜菊品种不同部位甙含量及主要甜味成分差异试验

试验结果表明,两个高RA型甜菊品种植株不同部位含甙量的变化规律是一致的。甜菊植株上部叶的RA含量占TSG含量比重最高,ST含量占TSG含量比重最低;自上而下RA含量占TSG含量比重依次递减,ST含量占TSG含量比重依次递增。分枝叶片中RA含量占TSG含量比重比主茎叶片高,ST含量占TSG含量比重比主茎叶片低,各部位TSG含量差异不显著。     

响应面分析法优化肉苁蓉苯乙醇苷提取反应 及其抗氧化反应研究

为优选管花肉苁蓉苯乙醇苷提取最佳工艺并对经分离纯化的苯乙醇苷进行抗氧化活性评价研究,以管花肉苁蓉中的苯乙醇苷得率为检测指标,采用响应面分析法,分别优化乙醇浸提法、超声提取法、微波提取法3种方法的提取效果,选出最优条件,并进行比较;采用DPPH法体外测定苯乙醇苷的抗氧化能力。结果表明,微波辅助提取法在最短时间内具有最高的苯乙醇苷得率,超声波辅助提取法次之,而乙醇浸提法时间最长,得率最低;随着苯乙醇苷浓度的增加其DPPH自由基清除能力也不断增强,当浓度在60~70μg·mg-1时达到最大。该试验对提高管花肉苁蓉的利用率具有实际指导意义,为管花肉苁蓉中苯乙醇苷化合物的药理和生物活性研究提供参考。     

中国南海脆二歧灯芯柳珊瑚Dichotella fragilis(Ridleg)化学成分的研究

以硅胶柱层析、Sephdex LH-20凝胶柱层析及半制备HPLC等层析分离技术,对脆二歧灯芯柳珊瑚Dicho-tella fragilis (Ridleg)的提取物进行分离纯化,并利用NMR、MS等波谱方法分析所得化合物的结构,共分离鉴定出5个化合物,包括3个19-羟基甾体皂苷类化合物junceelloside B (1)、4’-O-Acetyl-3-O-[β-D-arabino-pyranosyl-oxy]-cholest-5-ene-3β,19-diol (2)及junceelloside C (3),以及2个briarane型二萜类化合物junceol E(4)及gemmacolide A(5).以上化合物均为首次从脆二歧灯芯柳珊瑚中分离得到.化学分类学研究表明19-羟基甾体皂苷可作为Dichotella和Junceella属柳珊瑚的标志性次级代谢产物,此二属的柳珊瑚具有很近的亲缘关系.     

Structural Elucidation of Novel Saponins in the Sea Cucumber Holothuria lessoni

Sea cucumbers are prolific producers of a wide range of bioactive compounds. This study aimed to purify and characterize one class of compound, the saponins, from the viscera of the Australian sea cucumber Holothuria lessoni. The saponins were obtained by ethanolic extraction of the viscera and enriched by a liquid-liquid partition process and adsorption column chromatography. A high performance centrifugal partition chromatography (HPCPC) was applied to the saponin-enriched mixture to obtain saponins with high purity. The resultant purified saponins were profiled using MALDI-MS/MS and ESI-MS/MS which revealed the structure of isomeric saponins to contain multiple aglycones and/or sugar residues. We have elucidated the structure of five novel saponins, Holothurins D/E and Holothurinosides X/Y/Z, along with seven reported triterpene glycosides, including sulfated and non-sulfated saponins containing a range of aglycones and sugar moieties, from the viscera of H. lessoni. The abundance of novel compounds from this species holds promise for biotechnological applications.     

Cycloartane saponins from Astragalus peregrinus as modulators of lymphocyte proliferation

From Astragalus peregrinus, four cycloartane-type saponins have been isolated and their structures elucidated by spectral means as 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-β- -glucopyranoside (1), 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-α- -rhamnopyranosyl-(1→4)-β- -glucopyranoside (2), 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-α- -rhamnopyranosyl-(1→2)-β- -glucopyranoside (3) and 20(R),25-epoxy-9β,19-cyclolanostane-3β,6α,16β,24(S)-tetrol (24-O-acetyl)- 3-O-α- -rhamnopyranosyl-(1→2)-(6′-O-acetyl)-β- -glucopyranoside (4). Compounds 2 and 3 showed to stimulate the proliferation of mouse splenocytes and were not significantly cytotoxic.