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21.
We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further. 相似文献
22.
L. A. Sáenz-Carbonell I. E. Maldonado-Mendoza O. Moreno-Valenzula R. Clau-Uitz M. López-Meyer C. Oropeza V. M. Loyola-Vargas 《Applied biochemistry and biotechnology》1993,38(3):257-267
The release of alkaloids from root culturesDatura stramonium andCatharanthus roseus and thiophenes from root cultures ofTagetes patula was found to increase when the pH of the culture media (ranging from 4.8 to 7.0) was reduced to 3.5. The extent of the effect
was different in each type of culture. Increases ranged from 4- to 20-fold, which in some cases accounted for 75% of the total
secondary metabolite pool produced per flask. When the release of individual metabolites was measured, even larger increases,
were observed (nearly 400-fold for ajmalicine). Increased release of alkaloids fromC. roseus roots were also observed in cultures growing in a 14-L fermentor, when the medium pH was reduced. Reduction of the pH of
the media did not affect growth of the root cultures in subsequent subcultures. The importance of this treatment as a stategy
to improve the recovery of secondary metabolites from producing cultures is discussed. 相似文献
23.
矩阵平方根在数学的许多应用中起着重要的作用.本文研究M-矩阵平方根的计算问题,提出一种计算正则M-矩阵平方根的迭代方法.首先将这个问题转化为M-矩阵代数Riccati方程,进而提出一种有效的方法来求解这个特殊的MARE.理论分析表明,该方法在一定条件下是收敛的.数值实验表明该方法是可行的,且优于二项式迭代法. 相似文献
24.
作为Hom-Leibniz代数胚的代数类比, 本文引入Hom-Leibniz-Rinehart代数的概念. 证明了分裂的正则Hom-Leibniz-Rinehart代数$L$写成$L=U+\sum_{\gamma}I_\gamma$, 其中$U$为极大交换子代数$H$的子空间和$I_\gamma$为$L$的理想, 若$[\gamma]\neq[d]$, 满足$[I_\gamma, I_d]=0$. 随后分别发展了分裂Hom-Leibniz-Rinehart代数的根和权的连通技术.最后研究了紧致的正则Hom-Leibniz-Rinehart代数的结构. 相似文献
25.
张良忠 《北京理工大学学报》1998,18(3):331-335
探讨在电子光学成像系统中像评定的一种途径。方法,从静电这像差均方根理论出发,追迹计算大量空间轨迹的落点及系统均根半径,并由此衍算成弦财制传递函数。 相似文献
26.
李玲 《华南师范大学学报(自然科学版)》1998,(2):33-36
比较了MJ对两个不抗旱性玉米品种的影响.1-100mg/LMJ对抗旱性较弱品种SC701幼苗株高有抑制效应。 相似文献
27.
戴大临 《西南师范大学学报(自然科学版)》1998,23(4):454-461
顶端分生组织细胞有高的核质比,胸质中可见前质体和其它细胞,器。分化的组织原细胞中,皮层原细胞较中柱原和根冠表皮原细胞内前质体增多明显。 相似文献
28.
《Arabian Journal of Chemistry》2022,15(12):104330
The present study was carried out to design and synthesize a number of novel aromatic carboxamide derivatives of dehydroabietylamine. The preliminary antifungal assay indicated that most of title compounds displayed moderate to good antifungal activity toward the six fungal strains in vitro. Compounds 3i, 3q, 4b and 4d showed significant antifungal activity against Sclerotinia sclerotiorum, with EC50 values ranging from 0.067 ~ 0.393 mg/L. Compounds 3i, 4b and 4d also showed pronounced mycelial growth inhibition activities against B. cinerea and A. solani. Furthermore, in the in vivo assay, compound 4b exhibited brilliant protective activity against S. sclerotiorum-infected rape leaves. Meanwhile, the in vivo bioassay on tomato plants infected by B. cinerea showed that compound 3i and 4d displayed excellent protective activity at 200 mg/L, which were near to boscalid. Primary mechanistic study revealed that 4b could inhibit sclerotia formation as well as reduce the exopolysaccharide level. SEM and TEM analysis indicated that 4b possessed a strong ability to destroy the surface morphology of mycelia, cell structure and seriously interfere with the growth of the fungal pathogen. In addition, 4b exhibited good inhibitory activity (IC50 = 23.3 ± 1.6 μM) toward succinate dehydrogenase (SDH). Molecular modeling study confirmed the binding modes between compound 4b and SDH. The above antifungal results and fungicidal mechanism study revealed that this class of dehydroabietylamine derivatives could be potential SDH inhibitors and lead compounds for novel fungicides development. 相似文献
29.
30.
不同光质对一品红幼茎愈伤组织的诱导和器官分化影响的研究 总被引:11,自引:0,他引:11
一品红幼嫩茎段在离体培养过程中,不同光质对愈伤组织的诱导及根、芽分化有不同的效应.实验结果表明,红光、黄光、蓝光、绿光对愈伤组织的形成均有一定的促进作用,其促进作用大小为:红光>绿光>黄光、蓝光>白光;在芽的分化过程中,各色光均表现出不同程度的抑制作用,黄光的抑制作用最显著,绿光的抑制作用最弱. 相似文献