Development of a method to screen and isolate potential α‐glucosidase inhibitors from Panax japonicus C.A. Meyer by ultrafiltration,liquid chromatography,and counter‐current chromatography

A new assay based on ultrafiltration, liquid chromatography and mass spectrometry was developed for the rapid screening and identification of the ligands for α‐glucosidase from the extract of Panax japonicus. Six saponins were identified as α‐glucosidase inhibitors. Subsequently, the specific binding ligands, namely, notoginsenoside R₁, ginsenoside Rb₁, chikusetsusaponin V, chikusetsusaponin IV, chikusetsusaponin IVa, and ginsenoside Rd (the purities were 94.18, 95.43, 96.09, 93.26, 94.50, 93.86%, respectively) were separated by counter‐current chromatography using two‐phase solvent systems composed of tert‐butyl methyl ether, acetonitrile, 0.1% aqueous formic acid (3.8:1.0:4.4, v/v/v) and the solvent system composed of methylene chloride, isopropanol, methanol, 0.1% aqueous formic acid (5.8:1.0:6.0:2.2, v/v/v). The results demonstrate that ultrafiltration, liquid chromatography and mass spectrometry combined with high‐speed counter‐current chromatography might provide not only a powerful tool for screening and isolating α‐glucosidase inhibitors in complex samples but also a useful platform for discovering bioactive compounds for the prevention and treatment of diabetes mellitus.     

Separation of Photosynthetic Pigments by High-performance Liquid Chromatography: Comparison of Column Performance,Mobile Phase,and Temperature

High-performance liquid chromatography (HPLC) has been commonly used as method of separating and identifying photosynthetic pigments such as chlorophylls and carotenoids because of such advantages as speed, high resolution and sensitivity. In this technique, high separation relies largely on the type of column material. This study compared the efficiency of five reverse-phase columns, C8, C18, C18 monolithic, π-NAP, and cholester, for separation of photosynthetic pigments at several fixed conditions of mobile phase and temperature. This investigation also analysed the parameters of Δt_R and t_R ratio for selected pigments and resolution for structural isomers, such as α- and β-carotene. Among above columns tested, cholester column is suitable for separation of pigments not only for a broad range of polarity, but also for hydrophobic pigments in a simple mobile phase. This finding can help in the selection of column and HPLC parameters in separating photosynthetic pigments.     

Bioremediation of Aged Petroleum Oil Contaminated Soil: From Laboratory Scale to Full Scale Application

Large quantity of aged petroleum oil contamination such as dehydrated oil sludge, generated in the disposal process of oil-containing sewage in Indonesia. This study aims to investigate the OSCS removal by mean of bioremediation technique. Results found that petrofilic consortia and biosurfactants addition increased the removal efficiency up to 46% and 85%, respectively. At full scale application, this technique succeed in removing of 46 g TPH per kg soil from 4 883 m³ of OSCS during 16 mo of treatment. These results suggest that petrofilic consortia and biosurfactants addition stimulate the biodegradation and overcome the limitation of OSCS degradation process.     

Peptide-derived from Seahorse Exerts a Protective Effect against Cholinergic Neuronal Death in in vitro Model of Alzheimer's Disease

Hippocampus trimaculatus are highly valued and the most heavily traded seahorse species for traditional medicine purposes in many Asian countries. One of the main interesting features in H.trimaculatus is their richness in protein which can be hydrolyzed into bioactive peptides. In the previous study, H. trimaculatus was hydrolyzed using commercial enzymes, the peptides responsible for neuroprotective activity was identified as HTP-1. In the present study, in vitro co-culture system of neuronal (PC12) cells and Aβ₄₂ oligomer-stimulated murine microglia cells (BV2 cells) were used to test neuroprotective effects of HTP-1. The co-culture system showed that HTP-1 protected PC12 cells from BV2 neurotoxic responses. In addition, the activation of PI3K/Akt signaling pathway by HTP-1 were confirmed. The PI3K/Akt activation was found to be mediated through transforming growth factor-β (TGF-β) induction by HTP-1. Furthermore, this signaling pathway was found to up-regulate the expression of pro survival protein expression in PC12 cells. Collectively, HTP-1 has potent protective effect against neuronal cells death in in vitro model of Alzheimer's disease.     

Rigged modules I: Modules over dual operator algebras and the Picard group

In a previous paper we generalized the theory of $W^{?}$-modules to the setting of modules over nonselfadjoint dual operator algebras, obtaining the class of weak^?-rigged modules. At that time we promised a forthcoming paper devoted to other aspects of the theory. We fulfill this promise in the present work and its sequel “Rigged modules II”, giving many new results about weak^?-rigged modules and their tensor products. We also discuss the Picard group of weak* closed subalgebras of a commutative algebra. For example, we compute the weak Picard group of $H^{\infty }(\mathbb{D})$, and prove that for a weak* closed function algebra A, the weak Picard group is a semidirect product of the automorphism group of A, and the subgroup consisting of symmetric equivalence bimodules.     

Supercritical carbon dioxide extraction and gas chromatography–mass spectrometry analysis of Gymnema sylvestre R.Br. roots

Supercritical fluid extraction (SFE) achieves a wide range of applications since the past decade as a sustainable green technology. The present study investigates the process for producing high yield by supercritical carbon dioxide (Sc-CO₂) extraction form Gymnema sylvestre R.Br. roots. The effect of temperature and pressure on the percentage of accumulative yield is demonstrated. It is found that the highest yield is obtained at the temperature of 60°C and the pressure of 10?MPa. A proper review showed that there is a lack in the study of Sc-CO₂ extraction of this plant especially for optimization of SFE process which makes this study useful and valuable. For more benefit, the extract which achieves highest percentage is subjected to gas chromatography–mass spectrometry to study its chemical composition and detect the active principle compounds which present with high concentration and expected to be responsible of the pharmaceutical properties of the extract.     

Isolation of berberine tannate using a chromatography activity-guided fractionation from root bark of Berberis hispanica Boiss. & Reut.

Root bark of Berberis hispanica Boiss. & Reut. constitutes an important source of alkaloids and is traditionally used in Algeria and Morocco in many herbal formulations particularly for the treatment of stomach infections and colon cancer. Activity-guided fractionation of Berberis extract is developed by step-gradient elution on column chromatography followed by preparative HPLC to isolate the most antistaphylococcal compound. Solvent extraction-activity screening indicates that ethanol should be used as the extracting solvent as it has exhibited the highest activity against Staphylococcus aureus(Rosenbach ATCC6538) followed by water extract, whereas no activity is recorded for acetone and hexane extracts. Screening of collected fractions from chromatographic separations indicates that the fraction presenting the highest antistaphylococcal activity is identified as berberine tannate by UV spectrum, melting point measurement and confirmed by liquid chromatography coupled to mass spectrometry (LC/MS). The minimal inhibition concentration value of berberine tannate against S. aureus is evaluated at 5?µg?mL^?1.