Exploration and optimization of conditions for quantitative analysis of lignans in Schisandra chinensis by an online supercritical fluid extraction with supercritical fluid chromatography system

An online supercritical fluid extraction with supercritical fluid chromatography system could provide sequential extraction and quantitative analysis of lignans in Schisandra chinensis. Supercritical fluid extraction conditions were optimized at 15 MPa, 50°C, and 4 min with supercritical CO₂ adding 1% methanol; the elution volume and flow rate were set at 6 mL and 2 mL/min to blow extract out of the tank completely. The split‐flow rate was confirmed at 2.5%, which determines injection volume and accuracy of quantitative detection. The factors having negative influences on supercritical fluid chromatography retention in the online system, including sample loading forms and backpressure settings, are discussed in the paper. At last, an extraction‐quantitative method for lignans in Schisandra chinensis was developed, which could be finished within 19.5 min. The total content percentage of four lignans (Schisandrin, Schisandrin A, Schisandrin B and Schisandrol B) in four batches was respectively measured to be 1.42, 1.54, 1.62, and 1.90%.     

The effect of methyl jasmonate and light irradiation treatments on the stilbenoid biosynthetic pathway in Vitis vinifera cell suspension cultures

Grape stilbenes are a well-known family of plant polyphenolics that have been confirmed to have many biological activities in relation to health benefits. In the present study, we investigated the effect of methyl jasmonate (MeJA) elicitor at four different concentrations (25, 50, 100 and 200 μM) in combination or not with high-level light irradiation (10,000 LUX) on a cell line obtained from the pulp of Vitis vinifera cv. Shahani. Our results showed that the stilbene synthesis pathway is inhibited by high-light conditions. A concentration of 50 μM MeJA was optimum for efficient production and high accumulation of total phenolics and total flavonoids as well as total stilbenoids. Furthermore, we showed that there is a significant negative correlation between the production of these metabolites and cell growth. These data provide valuable information for the future scale-up of cell cultures for the production of these very high value compounds in bioreactor system.     

Constituents from Leaves of Scolopia chinensis

Two new phenolic glycosides, scolochinenosides A and B ( 1 and 2 ), and a new flavonoid glycoside, scoloside A ( 3 ), were isolated from the leaves of Scolopia chinensis (Lour .) Clos , together with eight known compounds. The structures of the new compounds were established on the basis of chemical and spectroscopic evidences.     

Indole Alkaloids from the Leaves of Anthocephalus chinensis

Anthocephalusine A ( 1 ) and 3β‐isodihydrocadambine 4‐oxide ( 2 ) were isolated from the leaves of Anthocephalus chinensis (Rubiaceae), together with five known compounds. The structures were established by spectroscopic methods including 2D‐NMR analyses.     

Effect of vinegar steaming on the composition and structure of Schisandra chinensis polysaccharide and its anti-colitis activity

In this study, infrared spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) technology were applied to systematically explain the Schisandra chinensis’s polysaccharide transformation in configuration, molecular weight, monosaccharide composition, and anti-ulcerative colitis (UC) activity after vinegar processing. Scanning electron microscopic results showed that the appearance of S. chinensis polysaccharide changed significantly after steaming with vinegar. The MALDI-TOF-MS results showed that the mass spectra of raw S. chinensis polysaccharides (RSCP) were slightly lower than those of vinegar-processed S. chinensis polysaccharides (VSCP). The RSCP showed higher peaks at m/z 1350.790, 2016.796, and 2665.985, all with left-skewed distribution, and the molecular weights were concentrated in the range of 1300–3100, with no higher peak above m/z 5000. The VSCPs showed a whole band below m/z 3000, with m/z 1021.096 being the highest peak, and the intensity decreased with the increase of m/z. In addition, compared to RSCPs, VSCPs can significantly increase the content of intestinal short-chain fatty acids (SCFAs). This study showed that the apparent morphology and molecular weight of S. chinensis’s polysaccharides significantly changed after steaming with vinegar. These changes directly affect its anti-UC effect significantly, and its mechanism is closely related to improving the structure and diversity of gut microbiota and SCFA metabolism.     

Dianthiamides A–E,Proline-Containing Orbitides from Dianthus chinensis

Orbitides are plant-derived small cyclic peptides with a wide range of biological activities. Phytochemical investigation of the whole plants of Dianthus chinensis was performed with the aim to discover new bioactive orbitides. Five undescribed proline-containing orbitides, dianthiamides A–E (1–5), were isolated from a methanolic extract of Dianthus chinensis. Their structures were elucidated by extensive analysis of 1D and 2D NMR and HRESI–TOF–MS as well as ESI–MS/MS fragmentation data. The absolute configuration of the amino acid residues of compounds 1–5 was determined by Marfey’s method. All compounds were tested for their cytotoxic activity, and dianthiamide A (1) exhibited weak activity against A549 cell line with IC₅₀ value of 47.9 μM.     

中国红豆杉细胞紫杉醇合成期特异表达新基因TS1-FL的部分cDNA克隆

采用mRNA差异显示技术(DDRT—PCR)比较了悬浮培养的中国红豆杉细胞合成紫杉醇前后的基因表达差异,并从紫杉醇合成期细胞中分离出一个特异表达的cDNA克隆TS1．TS1长度为638bp,序列相似性分析结果表明它代表一新基因序列(Genbank登录号：AF426429),将此新基因命名为TS1-FL．开放读框分析结果表明Tsl拥有一个不完整的开放读框,蛋白质同源性检索没有发现与TS1翻译序列有较大同源性的蛋白质．对此基因的进一步研究可揭示它在紫杉醇生物合成中所扮演的角色．     

中国绿螂精巢的组织学研究

运用光镜技术研究了中国绿螂精巢的组织结构及精子的发生过程.结果显示,中国绿螂的精巢由外壁及其内的无数生殖小管构成.外壁含单层柱状上皮细胞以及较厚的肌肉层.生殖小管的外层为生殖上皮,并由生殖上皮不断向腔内增殖产生精原细胞、初级精母细胞、次级精母细胞、精细胞和精子.伴随着染色质的浓缩,精子发生过程中细胞逐渐变小.中国绿螂的精子呈细长锥体状,形似辣椒,长约8～10 μm.     

轮台白杏叶片铁锰浓度光谱估算模型

建立基于光谱分析的轮台白杏叶片铁(Fe)、锰(Mn)元素浓度估算模型,为快速建立轮台白杏树体微量营养元素诊断体系提供技术途经。采用Unispec-SC光谱仪测定土壤肥力存在显著差异条件下轮台白杏果实不同生育时期叶片的光谱反射率,通过分析叶片中Fe和Mn元素浓度与Rλ和f′(Rλ)的相关性,筛选出光谱指示波段,并采用线性回归模型建立光谱估算模型以估算叶片Fe和Mn营养元素浓度。结果表明:轮台白杏果实不同生育时期叶片Fe元素的光谱敏感波段各不相同,果实坐果期和硬核期敏感波段分别为873和874nm,375和437nm。果实成熟期敏感波段为836和837nm而果实收后期敏感波段为325和1 054nm;轮台白杏果实四个生育时期Mn元素的光谱敏感波段分别为913和1 129nm,425和970nm,390和466nm,423和424nm;轮台白杏叶片Fe和Mn元素浓度均与光谱反射率一阶微分f′(Rλ)相关性最强,与之建立的线性光谱估算模型拟合度最高,且达到了显著或极显著水平。表明果实不同生育时期,轮台白杏叶片Fe和Mn元素的光谱指示波段不同,可根据双波段f′(Rλ)采用线性模型估算白杏叶片Fe和Mn元素浓度。     

濒危植物夏蜡梅光合生理生态特性

摘要：采用遮荫的方式设置3个光照梯度：全光照（CK）、37%全光照（37%RI）和10%全光照（10%RI）,于2007年7月中旬,对上述光环境中的夏蜡梅(Sinocalycanthus chinensis)幼苗的光合作用参数、叶绿素荧光参数进行测定,结果表明：3种光环境下,夏蜡梅的净光合速率日变化均为“双峰”曲线,CK和37%RI光环境下,午休现象明显;最大净光合速率的大小是37%RI＞CK＞10%RI;日均净光合速率的大小是37%RI＞10%RI＞CK.叶绿素荧光参数的日变化表明,10%RI光环境下光抑制现象不明显;37%RI光环境下在午间发生了明显的光抑制,但是光合机构可以恢复.全光照环境下发生了长期的光抑制,光合机构受到不可恢复的伤害.在夏蜡梅自然群落中,于2006年7月、10月和2007年4月下旬的晴朗天气,测定了群落冠层和林下2种光环境下夏蜡梅的净光合速率日进程,并与其主要伴生植物进行比较.7月夏蜡梅冠层的净光合速率日进程呈“双峰”曲线,有明显的“午休”现象;林下夏蜡梅则表现为“单峰”曲线;在4月和10月夏蜡梅及其伴生植物净光合速率日进程均呈“单峰”曲线.夏蜡梅3个季节的日均净光合速率的平均值比其它伴生植物低,在群落内种间竞争中将处于不利地位.