铈对悬浮培养南方红豆杉细胞可溶性蛋白和紫杉醇合成动态的影响

研究Ce4 对悬浮培养南方红豆杉细胞可溶性蛋白和紫杉醇合成的动态影响,Ce4＋对可溶性蛋白合成和细胞活力的影响存在“分区和分叉现象,低浓度Ce4 (0.010mmol.L^-1)可显著提高可溶性蛋白的合成强度和细胞活力,高浓度Ce4 (5.00mmol.L^-1)对细胞表现为强伤害作用,适宜浓度Ce4 (1.00mmol.L^-1)在短期内可大幅度提高紫杉醇的合成速度,达到最高积累。     

Identification and Optimization of a Novel Taxanes Extraction Process from Taxus cuspidata Needles by High-Intensity Pulsed Electric Field

Taxanes are a series of natural compounds with great application potential in antitumor therapy, whereas the lack of efficient taxanes extraction methods significantly hinders the development of taxanes. The high-intensity pulsed electric field (PEF) is a novel technology used to extract bioactive ingredients from food and other natural products. However, the prospect of using PEF for taxanes extraction remains to be elucidated. Herein, we extracted taxanes from Taxus cuspidata via PEF and explored the effects of seven extraction conditions on the yields of target compounds. The Placket–Burman design (PBD) assay revealed that electric field strength, pulse number, and particle size are key factors for taxanes extraction. The response surface methodology (RSM) and back-propagation neural network conjugated with genetic algorithm (GA-BP) were further used to model and predict the optimal extraction conditions, and GA-BP exerted higher reliability, leading to a maximum extraction yield of 672.13 μg/g under electric field strength of 16 kV/cm, pulse number of 8, particle size of 160 meshes, solid–liquid ratio of 1:60, a single extraction, centrifugal speed of 8000 r/min, and flow rate of 7 mL/min, which was 1.07–1.84 folds that of control, solid–liquid extraction (SL), and ultrasonic extraction (US) groups. Additionally, the scanning electron microscopy (SEM) results indicated that the sample particles extracted by PEF method exhibited a coarser surface morphology. Thus, we present for the first time that PEF is feasible for the extraction of taxanes from Taxus cuspidata and highlight the application value of the PBD, RSM, and GA-BP models in parameters optimization during extraction process.     

Simultaneous determination of main taxoids in Taxus needles extracts by solid-phase extraction-high-performance liquid chromatography with pentafluorophenyl column

A simple and accurate RP-HPLC method with pentafluorophenyl (PFP) column was developed for the simultaneous determination of six taxoids, i.e. paclitaxel, 10-deacetylbaccatin III (10-DAB III), 7-xylosyl-10-deacetyltaxol (7-xyl-10-DAT), 10-deacetyltaxol (10-DAT), cephalomannine and 7-epi-10-deacetyltaxol (7-epi-10-DAT), in the extracts from the needles of three Taxus species. The mobile phase consisted of acetonitrile (A) and water (B), and the extracts were separated using gradient elution program: 30% A at the first 7 min, and then ramped to 42% A at 8 min, held until 38 min. The developed method was validated with satisfactory precision (RSD < 2.61%), repeatability (RSD < 2.92%) and recovery (95.19-104.47%). The above taxoids in the extracts of Taxus cuspidata, T. chinensis and T. media were analyzed with the developed RP-HPLC method, and the results showed that the contents of different taxoids in three mentioned species were distinct. Maximal amounts of 10-DAB III, 7-xyl-10-DAT and 7-epi-10-DAT appeared in T. chinensis, while T. media possessed the highest content of 10-DAT, cephalomannine and paclitaxel. The developed method is accurate and efficient. It can be reliably used in the improved determination of taxoids for the quality control of Taxus species.     

一个新的紫杉烷二萜化合物的NMR研究

从云南红豆杉树皮中分离得到一个新的紫杉烷二萜化合物，用核磁共振１Ｈ谱、１３Ｃ谱、ＤＥＰＴ、１Ｈ－１ＨＣＯＳＹ、ＨＭＱＣ、ＨＭＢＣ谱，辅以其它谱的数据确定其为具５／７／６元环的７，９－ｄｉｄｅａｃｅｔｙｌｔａｘａｙｕｎｔｉｎ，指定了１Ｈ和１３Ｃ谱所有谱线的归属。     

A New Abietane Diterpenoid from the Barks of Taxus yunnanensis

Along with the major constituents taxoids, some non-taxane diterpenoids have also been isolated1. During the course of our phytochemical investigation on the bark of Taxus yunnanensis. Cheng et L. K. Fu, a new abietane diterpenoid, taxayunnin (1), and the known taxamairin C (2)2, were isolated. The structure elucidation of taxayunnin 1 was established by spectral analysis.Taxayunnin 1, pale yellow needles, mp 215oC, showed a molecular ion peak at m/z 346 [M+] in its EI mass spectrum, which…     

Efficient purification of paclitaxel from yews using high-performance displacement chromatography technique

Paclitaxel was purified using high-performance displacement chromatography (HPDC) technique, but not by the mechanism of HPDC. On small scale, paclitaxel was extracted with methanol from dry needles of Taxus canadensis and was enriched by extracting with chloroform after removing water-soluble hydrophilic components and hexane-soluble hydrophobic components. Then, 93-99% purity of paclitaxel was obtained using the HPDC technique. On large scale, taxanes were enriched by solvent partitioning between acetic acid/MeOH/H(2)O and hexane and extracted with CH(2)Cl(2). Taxanes except paclitaxel were further removed by extracting with methanol-water-trifluoroacetic acid (1.0:98.9:0.1, v/v/v). Applying HPDC technique to water-insoluble substances is problematic as this method requires a highly aqueous solvent system. In order to overcome this incompatibility, a system was set up where paclitaxel, although in low concentration, was extracted by methanol-water-trifluoroacetic acid (10.0:89.9:0.1, v/v/v). Recycling the extracting solvent to ensure minimal volume, the extracted paclitaxel was adsorbed on a C(18) trap column. A C(18) column of 4.6mm internal diameter was then connected to the trap column. The HPDC technique was thus carried out using an isocratic acetonitrile-water-trifluoroacetic acid (30.0:69.9:0.1, v/v/v) mobile phase consisting of a displacer cetylpyridinium trifluoroacetate (3mg/mL). Paclitaxel was co-eluted with the displacer and spontaneously crystallized. The crystal (114mg) showed 99.4% purity and only 10% of paclitaxel in the starting crude extract was lost during the enrichment/purification processes. This large scale purification method was successfully applied to purify paclitaxel from Chinese yew in small scale, suggesting general applicability of the method. This is the first report of purifying a water-insoluble natural product using HPDC technique.     

火焰原子吸收光谱法测定红豆杉中6种金属元素

用浓硝酸微波消解样品,火焰原子吸收光谱法直接测定了红豆杉中Fe、Cu、Mg、Ca、Mn、Zn 6种金属元素的含量.所测定的红豆杉中含有丰富的人体必需金属元素,采用此方法回收率在95.0%-104.0%之间.本方法简单、准确,结果令人满意.     

Some Taxane Derivatives from the Heartwood of Taxus Mairei

Five Taxane derivatives were isolated from Taxus mairei. Their structures were determined by spectroscopic methods and their physical constants were identical with the literature values. These are Taxa-4(20), 11-diene-2α, 5α, 7β-tetrol-5α, 7β, 10β-triacetate-2α-α-methylbutyrate(I); Taxa-4(20), 11-diene-2α, 5α, 9α, 10β, 13β-pentol-2α, 9α, 10β, 13α-tetraacetate-5α-cinnamate(II);Taxa-4(20), 11-diene-5α, 7β, 9α, 10β, 13α-pentol-pentaacetate(III); 7β-acetate-O-taxinine A(IV), 1β-hydroxy-baccatin-I(V).     

Taxezopidine G and 10-deacetyltaxezopidine G from Taxus baccata growing in Iran

A new taxoid, 10-deacetyltaxezopidine G, and a previously reported compound (Taxezopidine G) have been isolated from the needles and young stems of Taxus baccata L. growing in Iran, and the structures were determined on the basis of spectroscopic data. These two compounds were not previously encountered in Taxus baccata L. species. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 321–322, July–August, 2006.     

A New Abeotaxane Diterpenoid from the Seeds of Taxus mairei

Phytochemical investigation on the methanolic extracts of the Taxus mairei seeds resulted in the isolation of a new abeotaxane diterpenoid. The structure was characterized as 2α, 5α, 13α-trihydroxy-7β, 10β-diacetoxy-2(3→20)abeotaxa-4(20), 11- dien-9