Quantitative analysis of anti-inflammatory lignan derivatives in Ratanhiae radix and its tincture by HPLC–PDA and HPLC–MS

AbstractRoot preparations of Krameria lappacea (Dombey) Burdet et Simpson are traditionally used against oropharyngeal inflammation. Besides antimicrobial and astringent procyanidines, lignan derivatives, including ratanhiaphenol I, II, III and (+)-conocarpan, contribute to the activity of Ratanhiae radix, exerting a significant topical anti-inflammatory activity in vivo, and in vitro by inhibiting NF-κB and the formation of inflammatory prostaglandins and leukotrienes. Besides gravimetrical analysis of the ratanhiaphenols I, II and III, the content of these compounds in the herbal drug has never been determined. The developed HPLC method enables the quantification of twelve active lignan derivatives in the roots, and is also suitable for the determination of the constituents in Tinctura Ratanhiae. Separation was achieved on a phenyl-hexyl column material using a solvent gradient consisting of 0.02% aqueous TFA and a mixture of acetonitrile/methanol (75:25, v/v). Sensitivity, accuracy (recovery rates were between 95% and 105.6%), repeatability (RSD≤4.6%), and precision (intra-day precision≤4.8%; inter-day precision≤3.4%) of the method were determined. HPLC–MS experiments in positive and negative electrospray ionization mode confirmed identity and peak purity of analytes. The analysis of several root and tincture samples revealed that (+)-conocarpan and ratanhiaphenol II dominated with contents of 0.49–0.71% and 0.51–0.53% in the roots and 0.66–0.68mg/ml and 0.70–0.71mg/ml in the commercial tinctures, respectively

Unsupervised Learning of Nanoindentation Data to Infer Microstructural Details of Complex Materials

In this study, Cu-Cr composites were studied by nanoindentation. Arrays of indents were placed over large areas of the samples resulting in datasets consisting of several hundred measurements of Young's modulus and hardness at varying indentation depths. The unsupervised learning technique, Gaussian mixture model, was employed to analyze the data, which helped to determine the number of "mechanical phases" and the respective mechanical properties. Additionally, a cross-validation approach was introduced to infer whether the data quantity was adequate and to suggest the amount of data required for reliable predictions -- one of the often encountered but difficult to resolve issues in machine learning of materials science problems

Enhanced Transmission in Rolled-up Hyperlenses utilizing Fabry-Pe\'rot Resonances

We experimentally demonstrate that the transmission though rolled-up metal/semiconductor hyperlenses can be enhanced at desired frequencies utilizing Fabry-P\'erot resonances. By means of finite difference time domain simulations we prove that hyperlensing occurs at frequencies of high transmission.Comment: 3 pages, 3 figure

Purification of thonningianins A and B and four further derivatives from Thonningia sanguinea by one‐ and two‐dimensional centrifugal partition chromatography

International audienc

Gain in Three-Dimensional Metamaterials utilizing Semiconductor Quantum Structures

We demonstrate gain in a three-dimensional metal/semiconductor metamaterial by the integration of optically active semiconductor quantum structures. The rolling-up of a metallic structure on top of strained semiconductor layers containing a quantum well allows us to achieve a three-dimensional superlattice consisting of alternating layers of lossy metallic and amplifying gain material. We show that the transmission through the superlattice can be enhanced by exciting the quantum well optically under both pulsed or continuous wave excitation. This points out that our structures can be used as a starting point for arbitrary three-dimensional metamaterials including gain

Bioassay-Guided Isolation of Anti-Inflammatory Constituents of the Subaerial Parts of Cyperus articulatus (Cyperaceae)

Based on data from a previous ethnobotanical study in northern Angola, phytochemical investigations into the methanolic rhizomes and roots extract of Cyperus articulatus, monitored by in vitro assays, resulted in the recovery of 12 sesquiterpenes, 3 stilbenes, 2 phenolic acids, 1 monoterpene, and 1 flavonoid. Among them, 14 compounds were isolated for the first time from this species. Their inhibitory potential against nitric oxide (NO) production, as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, was evaluated in LPS-treated J774A.1 murine macrophages. Especially, both stilbene dimer trans-scirpusin B and trimer cyperusphenol B showed promising inhibitory activity against the production of the inflammatory mediator, NO, in a concentration-dependent manner (10-1 mu M). The obtained data are the first results confirming the anti-inflammatory potential of C. articulatus and support its indigenous use as a traditional remedy against inflammation-related disorders

Impact of preoperative positron emission tomography in patients with severely impaired LV-function undergoing surgical revascularization

In patients with ischemic cardiomyopathy, coronary artery bypass grafting (CABG) offers an important therapeutic option but is still associated with high perioperative mortality. Although previous studies suggest a benefit from revascularization for patients with defined viability by a non-invasive technique, the role of viability assessment to determine suitability for revascularization in patients with ischemic cardiomyopathy has not yet been defined. This study evaluates the hypothesis that the use of PET imaging in the decision-making process for CABG will improve postoperative patient survival. We reviewed 476 patients with ischemic cardiomyopathy (LV ejection fraction ≤0.35) who were considered candidates for CABG between 1994 and 2004 on the basis of clinical presentation and angiographic data. In a Standard Care Group, 298 patients underwent CABG. In a second PET-assisted management group of 178 patients, 152 patients underwent CABG (PET-CABG) and 26 patients were excluded from CABG because of lack of viability (PET-Alternatives). Primary endpoint was postoperative survival. There were two in hospital deaths in the PET-CABG (1.3%) and 30 (10.1%) in the Standard Care Group (P = 0.018). The survival rate after 1, 5 and 9.3 years was 92.0, 73.3 and 54.2% in the PET-CABG and 88.9, 62.2 and 35.5% in the Standard Care Group, respectively (P = 0.005). Cox-regression analysis revealed a significant influence on long-term survival of patient selection by viability assessment via PET (P = 0.008), of LV-function (P = 0.017), and age >70 (P = 0.016). Preoperative assessment of myocardial viability via PET identifies patients, who will benefit most from CABG

Allelopathic studies with furanocoumarins isolated from Ducrosia anethifolia. vitro and in silico investigations to protect legumes, rice and grain crops

Six different furanocoumarins were isolated from the aerial parts of Ducrosia anethifolia and tested in vitro for plant cell elongation in etiolated wheat coleoptile. They were also tested for their ability to control three different weeds: ribwort plantain, annual ryegrass, and common purslane. These compounds exhibited strong inhibition of plant cell elongation. In the case of (+)-heraclenin, the IC50 was lower than 20 mu M, indicating a better inhibition than the positive control Logran (R). Computational experiments for docking and molecular dynamics revealed for the investigated furanocoumarins bearing an epoxide moiety an improved fitting and stronger interaction with the auxin-like TIR1 ubiquitin ligase. Furthermore, the formed inhibition complex remained also stable during dynamic evaluation. Bidental interaction at the active site, along with an extended hydrogen-bond lifetime, explained the enhanced activity of the epoxides. The in vitro weed bioassay results showed that Plantago lan-ceolata was the most affected weed for germination, root, and shoot development. In addition, (+)-heraclenin displayed better inhibition values than positive control even at 300 mu M concentration