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41.
用栽培稻遗传图第6连锁群中与Pi-2(t)紧密连锁的RFLP标记RG64及其筛选出来的BAC克隆38D17作为探针,对药用野生稻和栽培稻进行荧光原位杂交(FISH),供试探针RG64及BAC克隆38D17均被定位于药用野生稻和栽培稻第6染色体.药用野生稻杂交信号的百分距离分别为44.87士5.33和46.50士4.57,而栽培稻则为35.85士3.06和36.05±2.44,信号检出率相应地为7.14%、42.53%、8.09%和40.78%.BAC克隆和RFLP探针杂交位置几乎一致,由此推知,与抗性基因Pi-2(t)连锁的BAC克隆在药用野生稻中的同源顺序就在第6染色体杂交信号出现的相应位置.在未封阻的情况下,药用野生稻多个染色体上具有信号,这表明它和栽培稻的Cot-IDNA重复序列在一定的程度上具有同源性.文中讨论了栽培稻BAC克隆对药用野生稻原位杂交物理作图的可行性和Cot-IDNA的制备所涉及的一些技术问题.  相似文献   
42.
本文以α-蒎烯与二氯卡宾的加成物3为原料,合成了马鞭草烯醇的类似物2,7,7-三甲基三环[4.1.1.0~(2,4)]-5-辛醇及其酯类和醚类衍生物。  相似文献   
43.
The present paper aims to formulate and characterize four phytotherapeutic ointments based on Hippophae fructus, Calendulae flos, Bardanae folium, and Millefolii herba, which are included in a novel ointment base. In order to investigate the healing properties of the ointments, in vivo experimental wound models of linear incision, circular excision, and thermal burn were performed on Wistar rats. Topical treatment was performed daily for 21 days. Determination of the wound contraction rate (WCR), the period of reepithelization, and histopathological examination were achieved. Additionally, for the tested ointments, oscillatory and rotational rheological tests were carried out, and for the extracts, HPLC analysis was performed. The results demonstrate that the tested novel ointments are safe for use and the most effective ointment proved to be the one based on Arctium lappa, followed by that of Calendulae flos.  相似文献   
44.
Rosmarinus officinalis extract (ROE) was studied chemically (mass loss, ML), electrochemically impedance spectrometry (EIS), and potentiodynamic polarization (PDP) as a corrosion inhibitor in 1 M nitric acid. According to ML, ROE is effective like a copper preservative in 1 M HNO3 acid solution at R.T by improving inhibitor concentration up to 77 % at 300 ppm and 25 °C. A study was conducted regarding the effect of temperature on copper adsorption, as well as the calculation of adsorption coefficients. Results indicated that physisorption increases with temperature, indicating a decrease in inhibition efficiency (%IE). Langmuir's adsorption model was consistent with the adsorption mechanism. Using the PDP method, the inhibitor accumulated on the copper surface in mixed forms. Moreover, EIS revealed that the value of double-layer capacitance dropped with an increased dose of ROE, while the charge transfer resistance improved. A different approach was taken to the examination of surfaces. Both theoretical studies and practical results were calculated and compared to demonstrate that the results were valid.  相似文献   
45.
The chemical composition of eight Tunisian Rosmarinus officinalis L. populations (A–H) from different bioclimatic areas has been examined by gas chromatography (GC) and GC-mass spectrometry. The essential oils are characterised by high amounts of oxygenated monoterpenes (58.2–71.7%) followed by monoterpene hydrocabons (15.1–26.7%). 1,8-Cineole, camphor, α-pinene and borneol are the main representative components. The antioxidant activity was investigated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing ability power assay and β-carotene bleaching test. Samples showed antiradical activity by inhibiting DPPH radical with IC50 values ranging from 375.3 to 592.8 μg mL? 1 for samples F and A, respectively. Sample A also showed the most promising activity in β-carotene bleaching test (IC50 of 31.9 μg mL? 1). The essential oils were also screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity. Sample G showed the highest activity against AChE (IC50 of 64.7 μg mL? 1) while sample D (IC50 of 29.5 μg mL? 1) exhibited the most potent activity against BChE.  相似文献   
46.
Two new triterpenoids and three 27-nor-triterpenoids were isolated from the stems (with bark) of Nauclea officinalis. Their structures were identified to be 2β,3β,19α,23-tetrahydroxy-urs-12-en-28-oic acid (1), 2β,3β,19α,23-tetrahydroxy-urs-12-en-28-O-[β-d-glucopyranosyl (1-2)-β-d-glucopyranosyl] ester (2), pyrocincholic acid 3β-O-α-l-rhamnopyranoside (3), pyrocincholic acid 3β-O-α-l-rhamnopyranosy1-28-O-β-d-glucopyranosyl ester (4), pyrocincholic acid 3β-O-α-l-rhamnopyranosy1-28-O-β-d-glucopyranosyl-(1-6)-β-d-glucopyranosyl ester (5) by spectroscopic methods including 1D, 2D NMR and HR-MS analyses. The cytotoxic activity of 15 against lung cancer A-549 cells was also investigated.  相似文献   
47.
南药巴戟天中十二种无机元素的初步研究   总被引:2,自引:0,他引:2  
采用火焰原子吸收光谱法测定了不同产地和生长期的巴戟天中Mn.Fe.Cu.Zn、Ca、Mg、K、Na、Cr、Co、Ni、Pb等十二种无机元素的含量及其灰化率,为研究巴戟天的药效及栽培技术提供了实验数据.  相似文献   
48.
Dental caries results from the bacterial pathogen Streptococcus mutans (S. mutans) and is the maximum critical reason for caries formation. Consequently, the present study aims to evaluate the antibacterial activity of a newly synthesized nanoantibiotic–Biodentine formulation. The silver nanoparticles (ROE-AgNPs) were biosynthesized from the usage of Rosmarinus officinalis L. extract (ROE) and conjugated with cefuroxime to form Cefuroxime-ROE-AgNPs. Using Biodentine™ (BIOD), five groups of dental materials were prepared, in which Group A included conventional BIOD, Group B included BIOD with ROE-AgNPs, Groups C and D included BIOD with Cefuroxime-ROE-AgNPs at concentrations of 0.5% and 1.5% cefuroxime, respectively, and Group E included BIOD with 1.5% cefuroxime. The synthesized ROE-AgNPs or Cefuroxime-ROE-AgNPs were characterized for conjugating efficiency, morphology, particle size, and in vitro release. Minimum inhibitory concentration (MIC) of the cefuroxime, ROE-AgNPs, and Cefuroxime-ROE-AgNPs were additionally evaluated against cefuroxime resistant S. mutans, which furthered antibacterial efficacy of the five groups of dental materials. The UV-Visible spectrum showed the ROE-AgNPs or Cefuroxime-ROE-AgNPs peaks and their formation displayed through transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, and Fourier transforms infrared (FTIR) analysis. The end result of Cefuroxime-ROE-AgNPs showed conjugating efficiency up to 79%. Cefuroxime-ROE-AgNPs displayed the highest antibacterial efficacy against S. mutans as compared to cefuroxime or ROE-AgNPs alone. Moreover, the MIC of ROE-AgNPs and Cefuroxime-ROE-AgNPs was detected against S. mutans to be 25 and 8.5 μg/mL, respectively. Consequently, Cefuroxime-ROE-AgNPs displayed that a decrease in the MIC reached to more than three-fold less than MIC of ROE-AgNPs on the tested strain. Moreover, Cefuroxime-ROE-AgNPs/BIOD was employed as a novel dental material that showed maximum antimicrobial activity. Groups C and D of novel materials showed inhibitory zones of 19 and 26 mm, respectively, against S. mutans and showed high antimicrobial rates of 85.78% and 91.17%, respectively. These data reinforce the utility of conjugating cefuroxime with ROE-AgNPs to retrieve its efficiency against resistant S. mutant. Moreover, the nanoantibiotic delivered an advantageous antibacterial effect to BIOD, and this may open the door for future conjugation therapy of dental materials against bacteria that cause dental caries.  相似文献   
49.
The recent coronavirus disease 2019 (COVID-19) pandemic is a global threat for healthcare management and the economic system, and effective treatments against the pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus responsible for this disease have not yet progressed beyond the developmental phases. As drug refinement and vaccine progression require enormously broad investments of time, alternative strategies are urgently needed. In this study, we examined phytochemicals extracted from Avicennia officinalis and evaluated their potential effects against the main protease of SARS-CoV-2. The antioxidant activities of A. officinalis leaf and fruit extracts at 150 µg/mL were 95.97% and 92.48%, respectively. Furthermore, both extracts displayed low cytotoxicity levels against Artemia salina. The gas chromatography–mass spectroscopy analysis confirmed the identifies of 75 phytochemicals from both extracts, and four potent compounds, triacontane, hexacosane, methyl linoleate, and methyl palminoleate, had binding free energy values of −6.75, −6.7, −6.3, and −6.3 Kcal/mol, respectively, in complexes with the SARS-CoV-2 main protease. The active residues Cys145, Met165, Glu166, Gln189, and Arg188 in the main protease formed non-bonded interactions with the screened compounds. The root-mean-square difference (RMSD), root-mean-square fluctuations (RMSF), radius of gyration (Rg), solvent-accessible surface area (SASA), and hydrogen bond data from a molecular dynamics simulation study confirmed the docked complexes′ binding rigidity in the atomistic simulated environment. However, this study′s findings require in vitro and in vivo validation to ensure the possible inhibitory effects and pharmacological efficacy of the identified compounds.  相似文献   
50.
A novel analytical method involving high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) was developed for simultaneous determination of 11 phenolic acids and 12 triterpenes in Sanguisorba officinalis L. Chromatographic separation was conducted with gradient elution mode by using a DiamonsilTM C18 column (250 mm × 4.6 mm, 5 μm) with the mobile phase of 0.1% acetic acid water (A) and methanol (B). The drift tube temperature of ELSD was set at 70 °C and the nitrogen cumulative flow rate was 1.6 L/min. The method was fully validated to be linear over a wide concentration range (R2 ≥ 0.9991). The precisions (RSD) were less than 3.0% and the recoveries were between 97.7% and 101.4% for all compounds. The results indicated that this method is accurate and effective for the determination of 23 functional components in Sanguisorba officinalis L. and could also be successfully applied to study the influence of processing method on those functional components in Sanguisorba officinalis L.  相似文献   
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