Effect of Pre‐ and Post–Combined Multidoses of Epigallocatechin Gallate and Coenzyme Q10 on Cisplatin‐Induced Oxidative Stress in Rat Kidney

The nephroprotective effect of coenzyme Q10 and epigallocatechin gallate was investigated in rats with acute renal injury induced by a single nephrotoxic dose of cisplatin. Two days prior to cisplatin administration, epigallocatechin gallate and coenzyme Q10 alone and in four different combinations were given for 6 days. The treatment with antioxidants significantly protected the cisplatin‐induced increase in the levels of blood urea nitrogen and serum creatinine. Both the antioxidants alone or in different combinations significantly compensated the increased malondialdehyde and reduced glutathione levels. Moreover, the decrease in the activities of superoxide dismutase, catalase, and glutathione peroxidase and the concentration of selenium, zinc, and copper ions were significantly attenuated in renal tissue. In conclusion, epigallocatechin gallate and coenzyme Q10 are equally effective against cisplatin‐induced nephrotoxicity, whereas the intervention by combining these two antioxidants was found to be highly effective at low doses in attenuating oxidative stress in rat kidney.     

Tricyclic 4,4-dimethyl-3,4-dihydrochromeno[3,4-d]imidazole derivatives as microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitors: SAR and in vivo efficacy in hyperalgesia pain model

A series of substituted tricyclic 4,4-dimethyl-3,4-dihydrochromeno[3,4-d]imidazole derivatives have been synthesized and their mPGES-1 biological activity has been disclosed in detail. Structure-activity relationship (SAR) optimization provided inhibitors with excellent mPGES-1 potency and low to moderate PGE₂ release A549 cell potency. Among the mPGES-1 inhibitors studied, 7, 9 and 11l provided excellent selectivity over COX-2 (>200-fold) and >70-fold selectivity for COX-1 except 11l, which exhibited dual mPGES-1/COX-1 activity. Furthermore, the above tested mPGES-1 inhibitors demonstrated good metabolic stability in liver microsomes, high plasma protein binding (PPB) and no significant inhibition observed in clinically relevant CYP isoforms. Besides, selected mPGES-1 tool compounds 9 and 11l provided good in vivo pharmacokinetic profile and oral bioavailability (%F = 33 and 85). Additionally, the representative mPGES-1 tool compounds 9 and 11l revealed moderate in vivo efficacy in the LPS-induced thermal hyperalgesia guinea pig pain model.     

Discovery and evaluation of novel FAAH inhibitors in neuropathic pain model

Conceptual design and modification of urea moiety in chemotype PF-3845/04457845, the bench marking irreversible inhibitor of fatty acid amide hydrolase (FAAH), led to discovery of a novel nicotinamide-based lead 12a having reversible mechanism of action. Focused SAR around the pyridine heterocycle (Ar) in 12a (Tables 1 and 2) resulted into four shortlisted compounds, (?)-12a, (?)-12i, (?)-12l–m. The required (?)-enantiomers were obtained via diastereomeric resolution of a novel chiral dissymmetric intermediate 15. Based on comparative profile of FAAH potency, metabolic stability in liver microsome, liability of inhibiting major hCYP450 isoforms, rat PK, and brain penetration ability, two SAR optimized compounds, (?)-12l and (?)-12m, were selected for efficacy study in rat model of chemotherapy-induced peripheral neuropathy (CIPN). Both the compounds exhibited dose related antihyperalgesic effects, when treated with 3–30?mg/kg po for 7?days. The effects at 30?mg/kg are comparable to that of PF-04457845 (10?mg/kg) and Tramadol (40?mg/kg).     

Biological Control of Root-Knot Nematode <i>Meloidogyne incognita</i> in <i>Psoralea corylifolia</i> Plant by Enhancing the Biocontrol Efficacy of <i>Trichoderma harzianum</i> Using Press Mud

Meloidogyne incognita is a plant pathogen causing root-knot disease and loss of crop yield. The present study aimed to use Trichoderma harzianum as a biocontrol agent against plant-parasitic nematodes and used press mud, which is a solid waste by-product of sugarcane, as a biocontrol agent and biofertilizer. Therefore, the combined application of T. harzianum and press mud may enhance nematode control and plant growth. Elemental analysis of press mud using scanning electron microscopy (SEM) integrated with an Energy Dispersive X-ray (EDX) analyzer revealed the presence of different elements such as C, O, Mg, Si, P, K, Ca, Cu and Zn. In addition, a greenhouse study was conducted to investigate the combined effects of press mud and T. harzianum on M. incognita reproduction and growth and the biochemical features of Psoralea corylifolia. The results showed that plant length, dry biomass, leaf area, the number of seeds per plant, chlorophyll a, chl b, carotenoid content, nitrate reductase, carbonic anhydrase, and nitrogen content were significantly increased (P ≤ 0.05) in the T2 plants (plants were treated with 100 g of press mud + 50 mL T. harzianum before one week of M. incognita inoculation), over inoculated plants (IC). Antioxidant enzyme activity of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in the foliage of P. corylifolia was significantly increased when plants were treated with press mud + T. harzianum. A significant reduction in the number of egg masses, nematode population, and root-knot index (RKI) was found in plants with T2 plants. These results suggest that the combined application of T. harzianum and press mud has the potential to control the M. incognita infection and can be used as an environmentally safe alternative to chemical nematicides and also help in the removal of sugarcane waste that causes environmental pollution.     

Tuning dual emission behavior of p-dialkylaminobenzonitriles by supramolecular interactions with cyclodextrin hosts

Ground state absorption and steady-state and time-resolved fluorescence measurements have been carried out to understand the host-guest interactions of p-diethylaminobenzonitrile (DEABN) and p-dimethylaminobenzonitrile (DMABN) dyes with alpha-cyclodextrin (alpha-CD) and beta-cyclodextrin (beta-CD) hosts. DEABN and DMABN dyes show both locally excited (LE) state and intramolecular charge transfer (ICT) state emissions in solution. The LE and ICT emissions of the dyes are seen to get modulated in the presence of alpha-CD and beta-CD hosts. The results indicate that the dyes form 1 : 1 inclusion complexes with both the hosts. Comparing the binding constants and the fluorescence characteristics of different dye x CD systems it is inferred that DEABN adopts a completely different orientation on complexation with alpha-CD than in the other cases of dye.CD systems. It is indicated that while in all other cases of dye x CD systems the N,N-dialkyl group of the dyes enters the host cavity leaving the C[triple bond, length as m-dash]N group projected out into the water phase, the DEABN dye enters the alpha-CD cavity (smallest CD) with its C[triple bond, length as m-dash]N group entering the host cavity. The differences in the orientation of the dye in the host cavities is understood to be determined by the requirement of maximum van der Waals contact of the encapsulated dye with the host cavity for maximum stability of the complex and the relative sizes of the substituents of the dye compared to the host cavities. From the observation that the binding constants for the present dye x CD systems are not that significantly high, it is inferred that the hydrophobic interaction mainly govern the inclusion complex formation in the present systems.     

Quantum chemical studies for oxidation of morpholine by Cytochrome P450

Since morpholine oxidation has recently been shown to involve Cytochrome P450, the study on its mechanism at molecular level using quantum chemical calculations for the model of cytochrome active site is reported here. The reaction pathway is investigated for two electronic states, the doublet and the quartet, by means of density functional theory. The results show that morpholine hydroxylation occurs through hydrogen atom abstraction and rebound mechanism. However, in the low spin state, the reaction is concerted and hydrogen atom abstraction yields directly ferric-hydroxy morpholine complex without a distinct rebound step while in quartet state the reaction is stepwise. The presence of nitrogen in a morpholine heterocycle is postulated to greatly facilitate hydrogen abstraction. The hydroxylated product undergoes intramolecular hydrogen atom transfer from hydroxy group to nitrogen, leading to the cleavage of the C-N bond and the formation of 2-(2-aminoethoxy) acetaldehyde. The cleavage of the C-N bond is indicated as the rate-determining step for the studied reaction. The assistance of explicit water molecule is shown to lower the energy barrier for the C-N bond cleavage in enzymatic environment whereas solvent effects mimicked by COSMO solvent model have minor influence on relative energies along the pathway.     

Enzyme immobilization via silaffin‐mediated autoencapsulation in a biosilica support

Enzymes and other biomolecules are often immobilized in a matrix to improve their stability or to improve their ability to be reused. Performing a polycondensation reaction in the presence of a biomolecule of interest relies on random entrapment events during polymerization and may not ensure efficient, homogeneous, or complete biomolecule encapsulation. To overcome these limitations, we have developed a method of incorporating autosilification activity into proteins without affecting enzymatic functionality. The unmodified R5 silaffin peptide from Cylindrotheca fusiformis is capable of initiating silica polycondensation in vitro at ambient temperatures and pressures in aqueous solution. In this study, translational fusion proteins between R5 and various functional proteins (phosphodiesterase, organophosphate hydrolase, and green fluorescent protein) were produced in Escherichia coli. Each of the fusion proteins initiated silica polycondensation, and enzymatic activity (or fluorescence) was retained in the resulting silica spheres. Under certain circumstances, the enzymatically‐active biosilica displayed improved stability relative to free enzyme at elevated temperatures. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

Differences in Free Volume Elements of the Carrier Matrix Affect the Stability of Microencapsulated Lipophilic Food Ingredients

Fish oil was encapsulated by spray-drying into different matrices based on n-octenylsuccinate-derivatised starch (nOSA starch) and carbohydrate blends varying in dextrose equivalent and molecular weight profile. Based on the development of the hydroperoxide and propanal content upon storage significant differences in the stability of the microencapsulated oil were observed. With 40 mmol/kg oil the hydroperoxide content after eight weeks of storage at 20 °C and 33% relative humidity was lowest in fish oil encapsulated in a matrix containing nOSA starch and maltose. In contrast, the lowest stability was observed in fish oil encapsulated in a matrix based on nOSA starch and maltodextrin with a dextrose equivalent of 18. Physical characteristics like viscosity of the feed emulsion and oil droplet size, which influence drying behaviour as well as particle characteristics like particle size, density or surface area did not differ and thus cannot explain the differences in the rate of autoxidation. Positron annihilation lifetime spectroscopy clearly showed distinct differences in the ortho-positronium lifetime, and thus in the size of free volume elements between the carrier matrices. It is suggested that as a consequence, the matrices differed in oxygen diffusivity, which must be considered to be a key determinant in autoxidation of fish oil encapsulated in glassy carbohydrate matrices.     

Improved production of monoclonal antibodies through oxygen-limited cultivation of glycoengineered yeast

Glycoengineering technology can elucidate and exploit glycan related structure-function relationships for therapeutic proteins. Glycoengineered yeast has been established as a safe, robust, scalable, and economically viable expression platform. It has been found that specific productivity of antibodies in glycoengineered Pichia pastoris is a non-linear function of specific growth rate that is dictated by a limited methanol feed rate. The optimal carbon-limited cultivation requires an exponential methanol feed rate with an increasing biomass concentration and more significantly an increase in heat and mass transfer requirements that often become the limiting factor in scale-up. Both heat and mass transfer are stoichiometrically linked to the oxygen uptake rate. Consequently an oxygen-limited cultivation approach was evaluated to limit the oxygen uptake rate and ensure robust and reliable scale-up. The oxygen-limited process not only limited the maximum oxygen uptake rate (and consequently the required heat removal rate) in mut+ P. pastoris strains but also enabled extension of the induction phase leading to an increased antibody concentration (1.9 g L⁻¹ vs. 1.2 g L⁻¹), improved N-glycan composition and galactosylation, and reduced antibody fragmentation. Furthermore, the oxygen-limited process was successfully scaled to manufacturing pilot scale and thus presents a promising process option for the glycoengineered yeast protein expression platform.