Die Lagerung von radioaktiven Stoffen

P³² and C¹⁴ have been used together to identify and tgrace the photosynthates of Zea mays during the seedling stage. By this double labelling technique and single labelling with C¹⁴O₂ and H₃P³²O₄, carbohydrates, amino acids, and phosphoproteins were identified on paper chromatograms. Tables and figures summarise the results obtained under different mineral deficiency. These results indicate the effects of the absence of P, Mg, K, N, Ca, and trace elements on both respiration and photosynthesis.     

Purification of the total steroidal saponins from fenugreek seeds (Trigonella foenum-graecum L.) using aqueous two-phase system and determination of diosgenin content using micellar electrokinetic chromatography method

The total steroidal saponins, particularly its major steroidal sapogenin (diosgenin), are the main active principles of fenugreek seed extract. In this study, an ethanol-salt aqueous two-phase system (ATPS) was explored for the purification of the total steroidal saponins, and the process conditions were optimized by response surface methodology (RSM). Under the optimized conditions, the RSM predicted recovery of the total steroidal saponins in the top phase of ATPS was 97.9%, which agreed with the average experimental recovery (98.3 ± 4.2% (n = 6)). Moreover, a rapid micellar electrokinetic chromatography (MEKC) method was developed for the determination of diosgenin from extracts. The diosgenin content in the ATPS top phase extract was 3-fold higher than that in crude extract, suggesting this ATPS having a great potential for purification pharmacological active ingredients from fenugreek seeds.     

The use of fast field cycling to evaluate the time domain relaxation of starches from tropical fruit seeds

ABSTRACT

A proton NMR relaxation study of the molecular dynamics in flour samples of ‘Eugenia uniflora’ (‘Pitanga’), ’Citrus reticulate’ (‘Tangerine’), ‘Prunus persica’ (‘Peach’), ‘Vitis vinifera’ (‘Grape’), and ‘Cucumis melo’ (‘Honeydew melon’) seeds is presented. The spin–lattice relaxation time was obtained over a broad frequency range from 100?kHz to 100?MHz using both conventional and fast field-cycling NMR techniques. This relaxometry study made possible a comparison between the molecular dynamics behaviour of starch from different fruit seeds and from potatoes. I was possible to conclude that the spin–lattice dispersion presents slightly differences for all samples, in particular at low frequencies. All relaxation dispersions could be well interpreted in terms of power-law relaxation models and domains with different power-law relaxation exponents. For the Peach seeds flour the relaxation dispersion at low frequencies was very similar to that observed for potato’s starch incorporated with 5% organoclay Viscogel B8 nanoparticles.     

自然老化谷类种子的二维红外光谱研究

种粮老化影响种子活力及粮食品质。利用傅里叶变换红外光谱(FT-IR),二阶导数红外光谱(SD-IR)和二维相关红外光谱(2D-IR)方法对不同储藏年份的大麦,小麦,稻谷,玉米和高粱种子进行区分研究。结果显示,原始光谱中几个峰强比有差异;在二阶导数红外光谱中,不同储藏年份种子在1 800～800 cm-1范围内的吸收峰强度和形状显示出差异。二维相关红外光谱结果显示：大麦在1 350～1 800 cm-1,小麦,稻谷,玉米和高粱在860～1 690 cm-1范围内有明显差异,随储藏年份增加,自动峰和交叉峰的数目减少,强度减弱。结果表明,应用傅里叶变换红外光谱结合二维相关红外光谱能有效快速地区分不同储藏年份的谷类种子。     

Ferromagnetic seeding for the magnetic targeting of drugs and radiation in capillary beds

A new implant assisted-magnetic drug targeting approach is introduced and theoretically analyzed to demonstrate its feasibility. This approach uses ferromagnetic particles as seeds for collecting magnetic drug carrier particles at the desired site in the body, such as in a capillary bed near a tumor. Based on the capture cross section (λ_c) approach, a parametric study was carried out using a 2-D mathematical model to reveal the effects of the magnetic field strength (μ₀H₀=0.01–1.0 T), magnetic drug carrier particle radius (R_p=20–500 nm), magnetic drug carrier particle ferromagnetic material content (x_fm,p=20–80 wt%), average blood velocity (u_B=0.05–1.0 cm/s), seed radius (R_s=100–2000 nm), number of seeds (N_s=1–8), seed separation (h=0–8R_s), and magnetic drug carrier particle and seed ferromagnetic material saturation magnetizations (iron, SS 409, magnetite, and SS 304) on the performance of the system. Increasing the magnetic field strength, magnetic drug carrier particle size, seed size, magnetic drug carrier particle ferromagnetic material content, or magnetic drug carrier particle or seed saturation magnetization, all positively and significantly affected λ_c, while increasing the average blood velocity adversely affected it. Increasing the number of seeds or decreasing the seed separation, with both causing less significant increases in λ_c, verified that cooperative magnetic effects exist between the seeds that enhance the performance. Overall, these theoretical results were encouraging as they showed the viability of this minimally invasive, implant assisted-magnetic drug targeting approach for targeting drugs or radiation in capillary beds.     

Extract with high 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibitory capability from pericarp and seed of mangosteen (Garcinia mangostana L.) using microwave-assisted extraction (MAE) two-phase solvent technique

The human body needs compounds that are antioxidants to prevent oxidative stress. Some parts of the mangosteen fruit (Garcinia mangostana L.) have been known as sources of bioactive compounds that have antioxidant properties. The pericarp and seeds of mangosteen were extracted using the MAE method to produce the extract with the greatest antioxidant activity. There are two types of solvent mixtures used in the extraction process: single-phase and two-phase solvents. The solvents used were ethanol (EtOH), ethyl acetate (EtOAc), isopropyl alcohol (IPA), and water. First, utilizing dried mangosteen pericarp powder as the raw material, a study was undertaken to determine the ideal operating conditions for the MAE process. A one-factor-at-a-time approach was used to find the best operating conditions. A mixture of solvents with varied ratios (mL/mL), extraction temperature (°C), extraction time (min), and solid to solvent ratio (g/mL) were applied as independent variables. Then, dried mangosteen seed powder extraction was carried out based on the best-operating conditions previously achieved. The DPPH scavenging activity, total phenolic content (TPC) value, and α-mangostin content of the two extracts were compared. It was discovered that the mangosteen pericarp extract showed higher antioxidant activity (IC₅₀ DPPH = 9.40 µg/mL) than the mangosteen seed extract (IC₅₀ DPPH = 37.54 µg/mL), even slightly better than ascorbic acid (IC₅₀ DPPH = 10.47 µg/mL). The best extract was produced from the bottom phase of two-phase solvent system (EtOAc:EtOH:Water 2:1:2), with an MAE temperature of 50 °C, a time of 4 min, and a solid-to-solvent ratio of 1:16. The TPC value of the best extract is 903.54 mgGAE/g extract, with a yield of 16.53 % and an α-mangostin concentration of 0.11 %.     

A novel thiolysis-high-performance liquid chromatography method for the determination of proanthocyanidins in grape seeds

A novel thiolysis-high-performance liquid chromatography method for the quantitative determination of total proanthocyanidins and the mean degree of polymerization in grape seeds has been developed. Following thiolysis with formic acid and benzyl mercaptan, reaction products were separated and purified. Three proanthocyanidin monomers and three derivatives were obtained and their structures were identified by liquid chromatography-mass spectrometry, FTIR spectroscopy, and NMR spectroscopy. A decomposition model of the thiolysis products and a correction formula for proanthocyanidins concentration were established. This thiolysis-high-performance liquid chromatography method displayed good calibration linearity (R² > 0.999 over the concentration range 0.01 to 10 mg/mL), excellent accuracy (recoveries of 97.9–99.6%), and precision (repeatability relative standard deviations of 0.45–0.75%). This method is suitable for the quantitative analysis of proanthocyanidins in grape seed products.     

Theasaponin E1 Inhibits Platinum-Resistant Ovarian Cancer Cells through Activating Apoptosis and Suppressing Angiogenesis

Novel therapeutic strategies for ovarian cancer treatment are in critical need due to the chemoresistance and adverse side effects of platinum-based chemotherapy. Theasaponin E₁ (TSE1) is an oleanane-type saponin from Camellia sinensis seeds. Its apoptosis-inducing, cell cycle arresting and antiangiogenesis activities against platinum-resistant ovarian cancer cells were elucidated in vitro and using the chicken chorioallantoic membrane (CAM) assay. The results showed that TSE1 had more potent cell growth inhibitory effects on ovarian cancer OVCAR-3 and A2780/CP70 cells than cisplatin and was lower in cytotoxicity to normal ovarian IOSE-364 cells. TSE1 significantly induced OVCAR-3 cell apoptosis via the intrinsic and extrinsic apoptotic pathways, slightly arresting cell cycle at the G2/M phase, and obviously inhibited OVCAR-3 cell migration and angiogenesis with reducing the protein secretion and expression of vascular endothelial growth factor (VEGF). Western bolt assay showed that Serine/threonine Kinase (Akt) signaling related proteins including Ataxia telangiectasia mutated kinase (ATM), Phosphatase and tensin homolog (PTEN), Akt, Mammalian target of rapamycin (mTOR), Ribosome S6 protein kinase (p70S6K) and e IF4E-binding protein 1(4E-BP1) were regulated, and Hypoxia inducible factor-1α (HIF-1α) protein expression was decreased by TSE1 in OVCAR-3 cells. Moreover, TSE1 treatment potently downregulated protein expression of the Notch ligands including Delta-like protein 4 (Dll4) and Jagged1, and reduced the protein level of the intracellular domain (NICD) of Notch1. Combination treatment of TSE1 with the Notch1 signaling inhibitor tert-butyl (2S)-2-[[(2S)-2-[[2-(3,5-difluorophenyl)acetyl]amino]propanoyl]amino]-2-phenylacetate (DAPT), or the Akt signaling inhibitor wortmannin, showed a stronger inhibition toward HIF-1α activation compared with single compound treatment. Taken together, TSE1 might be a potential candidate compound for improving platinum-resistant ovarian cancer treatment via Dll4/Jagged1-Notch1-Akt-HIF-1α axis.     

Determination of thiram residues in canola seeds,water and soil samples using solid-phase microextraction with polypyrrole film followed by ion mobility spectrometer

Thiram fungicide contamination in canola seeds, water and soil samples was monitored using headspace solid-phase microextraction (HS-SPME) combined with ion mobility spectrometer (IMS) to assess its environmental relevance. The influence of the various analytical parameters on microextraction procedure including pH, ionic strength, equilibrium time and temperature has been evaluated and optimised. HS-SPME-IMS allowed the determination of thiram in the concentration range of 10–300 ng mL^?1 (R² > 0.99). The detection limit and relative standard deviation were 6 ng mL^?1 and 8% for five replicate analyses, respectively. The HS-SPME-IMS method with polypyrrole film doped with dodecylsulfate (PPy-DS) as solid phase provided an effective sample clean-up for the monitoring of thiram in canola and soil samples. The main advantages of this method are sensitive, good repeatability, organic solvent-free, less time-consuming and relatively inexpensive.     

K_2CO_3活化制备花椒籽废渣的活性炭及其对对硝基苯酚的吸附性能

采用花椒籽废渣(RPS)为原料,K_2CO_3为活化剂制备了花椒籽废渣活性炭(KAC),以期实现农业废弃物的再利用。采用傅里叶变换红外光谱仪(FTIR)、扫描电子显微镜(SEM)、热重分析仪(TGA)、能量散射光谱(EDS)、X射线衍射仪(XRD)和气体吸附法等技术手段对其进行表征。分析了浸渍比(m(K_2CO_3)∶m(RPS))、浸渍时间、活化温度和活化时间对制备花椒籽废渣活性炭的影响,并且测试了花椒籽废渣活性炭对对硝基苯酚的吸附行为。研究结果表明,在浸渍比为0.8,浸渍时间为12 h,活化温度为550℃,活化时间为60min的条件下,活性炭的产率为29.3%,比表面积为1210 m~2/g,碘值为1002 mg/g,对亚甲基蓝的平衡吸附容量为362 mg/g,灰分为2.2%,水分为6.6%。对对硝基苯酚的吸附性能研究表明,293 K,pH=8.0,吸附180min后可达到吸附平衡,对硝基苯酚的吸附容量为406 mg/g,吸附可用Langmuir等温方程较好模拟,吸附为自发的放热过程。动力学研究表明该吸附符合准二级动力学模型。K_2CO_3活化法制备花椒籽废渣活性炭原料廉价,工艺简单,制得的活性炭吸附性能优异,具有较好的应用前景。