Effect of <Emphasis Type="Italic">Rol</Emphasis> Genes on Polyphenols Biosynthesis in <Emphasis Type="Italic">Artemisia annua</Emphasis> and Their Effect on Antioxidant and Cytotoxic Potential of the Plant

Flavonoids are famous for their antioxidant capacity and redox potential. They can combat with cell aging, lipid peroxidation, and cancer. In the present study, Artemisia annua hybrid (Hyb8001r) was subjected to qualitative and quantitative analysis of flavonoids through HPLC. Rol genes transgenics of A. annua were also evaluated for an increase in their flavonoid content along with an increase in antioxidant and cytotoxic potential. This was also correlated with the expression level of flavonoids biosynthetic pathway genes as determined by real-time qPCR. Phenylalanine ammonia-lyase and chalcone synthase genes were found to be significantly more highly expressed in rol B (four to sixfold) and rol C transgenics (3.8–5.5-fold) than the wild-type plant. Flavonoids detected in the wild-type A. annua through HPLC include rutin (0.31 mg/g DW), quercetin (0.01 mg/g DW), isoquercetin (0.107 mg/g DW) and caffeic acid (0.03 mg/g DW). Transgenics of the rol B gene showed up to threefold increase in rutin and caffeic acid, sixfold increase in isoquercetin, and fourfold increase in quercetin. Whereas, in the case of transgenics of rol C gene, threefold increase in rutin and quercetin, 5 fold increase in isoquercetin, and 2.6-fold increase in caffeic acid was followed. Total phenolics and flavonoids content was also found to be increased in rol B (1.5-fold) and rol C (1.4-fold) transgenics as compared to the wild-type plant along with increased free radical scavenging activity. Similarly, the cytotoxic potential of rol gene transgenics against MCF7, HeLA, and HePG2 cancer cell lines was found to be significantly enhanced than the wild-type plant of A. annua. Current findings support the fact that rol genes can alter the secondary metabolism and phytochemical level of the plant. They increased the flavonoids content of A. annua by altering the expression level of flavonoids biosynthetic pathway genes. Increased flavonoid content also enhanced the antioxidant and cytotoxic potential of the plant.     

Nano–silica functionalized with thiol–based dendrimer as a host for gold nanoparticles: An efficient and reusable catalyst for chemoselective oxidation of alcohols

In this paper, we present the synthesis of Au nanoparticles supported on nanosilica thiol based dendrimer, nSTDP. The catalyst was prepared by reduction of HAuCl₄ with NaBH₄ in the presence of nSTDP. The resulting Au_np–nSTDP materials were characterized by FT–IR and UV–vis spectroscopic methods, SEM, TEM, TGA, XPS and ICP analyses. The characterization of the catalyst showed that Au nanoparticles with the size of 2–6 nm are homogeneously distributed on the nSTDP dendrimer with a catalyst loading of about 0.19 mmol/g of catalyst. The Au_np–nSTDP catalyst was used in the oxidation of alcohols with tert–butyl hydroperoxide (TBHP) as oxidant. The influence of vital reaction parameters such as solvent, oxidant and amount of catalyst on the oxidation of alcohols was investigated. These reactions were best performed in an acetonitrile/water mixture (3:2) in the presence of 0.76 mol% of the catalyst on the basis of the Au content at 80 °C under atmospheric pressure of air to afford the desired products in high yields (80–93% for benzyl alcohols). The Au_np–nSTDP catalyst exhibited a high selectivity toward the corresponding aldehyde and ketone (up to 100%). Reusabiliy and stability tests demonstrated that the Au_np–nSTDP catalyst can be recycled with a negligible loss of its activity. Also this catalytic exhibited a good chemoselectivity in the oxidation of alcohols.     

Stability assessment of FDA-approved ramucirumab monoclonal antibody; validated SE-HPLC method for degradation pattern evaluation

Ramucirumab (RAMU) is a recently US Food and Drug Administration-approved monoclonal antibody that is included in various anticancer protocols. It has a structural complexity and high degradation risk that have a significant effect on its safety and effectiveness. The major aim of this work was to assess the degradation pattern of RAMU based on physicochemical characterization. Mechanical agitation, repeated freeze–thaw cycles, pH and temperature were the selected stress conditions to which RAMU samples were subjected. The SE-HPLC method was applied and validated to monitor the RAMU monomer along with its aggregates and/or fragments. The purity of the separated peaks together with system suitability parameters were determined through the calculation of percentage purity and percentage drop in RAMU concentration. The results were interpreted by correlating them with those of dynamic light scattering and reducing and non-reducing sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Samples incubated at pH 2.0–10.0 and 37°C for up to 4 weeks were analysed, recording detection of reversed phase (RP) aggregates and low molecular weight peptide fragments. Similarly, samples under short-term storage conditions of 4 weeks at different temperatures (−20, 2–8, 25, 37 and 50°C) showed low molecular weight peptide fragments but to a lesser extent. These results highlight the alarming effect on RAMU multidose vial efficacy and safety.     

Pricing decisions in a dual supply chain of organic and conventional agricultural products

Annals of Operations Research - We analyze a dual-channel supply chain comprising two suppliers that offer vertically-differentiated agricultural products; specifically, one offers an organic...     

Novel ethylene/norbornene copolymers as nonreleasing antioxidants for food‐contact polyolefinic materials

An efficient procedure for the copolymerization of ethylene (E) with a novel norbornenic comonomer (N_ArOH) bearing a stabilizing moiety analogous to commercial antioxidant 2,6‐di‐tert‐butyl‐4‐methylphenol (BHT) is successfully developed. This study is aimed at: i) tuning the concentration of the stabilizing function along the polymer chain, and ii) preparing “nonreleasing” polymeric additives specifically destined to protect commercial low‐density polyethylene (LDPE). Films obtained from blends of the novel E/N_ArOH copolymers with an antioxidant‐free LDPE matrix are characterized by superior thermal, thermo‐oxidative, and photostability when compared not only with neat LDPE films but also with films stabilized by the commercial BHT additive. Specific migration tests conducted in order to investigate the nonreleasing character of the novel macromolecular additives confirm the reduced risk of migration, from the films into food simulants, of unreacted comonomer or degradation products bearing the antioxidant moiety. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 , 51, 1007–1016     

Sulfate intercalated layered double hydroxides prepared by the reformation effect

The removal of the sulfate anion from water using synthetic hydrotalcite (Mg/Al LDH) was investigated using powder X-ray diffraction (XRD) and thermogravimetric analysis (TG). Synthetic hydrotalcite Mg₆Al₂(OH)₁₆(CO₃)·4H₂O was prepared by the co-precipitation method from aluminum and magnesium chloride salts. The synthetic hydrotalcite was thermally activated to a maximum temperature of 380 °C. Samples of thermally activated hydrotalcite where then treated with aliquots of 1000 ppm sulfate solution. The resulting products where dried and characterized by XRD and TG. Powder XRD revealed that hydrotalcite had been successfully prepared and that the product obtained after treatment with sulfate solution also conformed well to the reference pattern of hydrotalcite. The d₍₀₀₃₎ spacing of all samples was found to be within the acceptable region for a LDH structure. TG revealed all products underwent a similar decomposition to that of hydrotalcite. It was possible to propose a reasonable mechanism for the thermal decomposition of a sulfate containing Mg/Al LDH. The similarities in the results may indicate that the reformed hydrotalcite may contain carbonate anion as well as sulfate. Further investigation is required to confirm this.