Green Synthesis of Chromium Nanoparticles and Their Effects on the Growth of the Prawn Macrobrachium rosenbergii Post-larvae.

This study deals with synthesis of chromium nanoparticles (CrNPs) from potassium dichromate using the aqueous extract of Allium sativum. They were characterized through UV-VIS light, FE-SEM, EDX, XRD, and FT-IR, which revealed uniform, mono-dispersive, and highly stable CrNPs of 31-64-nm size. The Artemia nauplii was enriched with 4.94 mg/L of CrNPs (24-h LC50) at different durations (½, 1, 2, and 4 h) and then fed to Macrobrachium rosenbegii post-larvae (PL) for 30 days as live feed. The results showed that ½- and 1-h enriched Artemia nauplii led to significant improvements in nutritional indices including growth and survival, and concentrations of tissue biochemical constituents, such as total protein, amino acid, carbohydrate, and lipid of M. rosenbergii PL (P < 0.05), which suggests that this concentration of CrNPs was non-toxic to M. rosenbergii PL. This was confirmed by the insignificant alterations recorded in activities of SOD and CAT (P > 0.05) in M. rosenbergii PL fed with ½- and 1-h enriched Artemia nauplii as live feed. After that, SOD and CAT activities started to increase. Therefore, this optimized concentration of CrNPs (4.94 mg/L) is recommended for enrichment of Artemia nauplii for ½-1-h duration as a sustainable material in the nursery of M. rosenbergii.

Multigram synthesis and in vivo efficacy studies of a novel multitarget anti-Alzheimer's compound.

We describe the multigram synthesis and in vivo efficacy studies of a donepezil‒huprine hybrid that has been found to display a promising in vitro multitarget profile of interest for the treatment of Alzheimer's disease (AD). Its synthesis features as the key step a novel multigram preparative chromatographic resolution of intermediate racemic huprine Y by chiral HPLC. Administration of this compound to transgenic CL4176 and CL2006 Caenorhabditis elegans strains expressing human Aß42, here used as simplified animal models of AD, led to a significant protection from the toxicity induced by Aß42. However, this protective effect was not accompanied, in CL2006 worms, by a reduction of amyloid deposits. Oral administration for 3 months to transgenic APPSL mice, a well-established animal model of AD, improved short-term memory, but did not alter brain levels of Aß peptides nor cortical and hippocampal amyloid plaque load. Despite the clear protective and cognitive effects of AVCRI104P4, the lack of Aß lowering effect in vivo might be related to its lower in vitro potency toward Aß aggregation and formation as compared with its higher anticholinesterase activities. Further lead optimization in this series should thus focus on improving the anti-amyloid/anticholinesterase activity ratio.

Metabolite profiling of wheat (Triticum aestivum L.) phloem exudate.

BACKGROUND: Biofortification of staple crops with essential micronutrients relies on the efficient, long distance transport of nutrients to the developing seed. The main route of this transport in common wheat (Triticum aestivum) is via the phloem, but due to the reactive nature of some essential micronutrients (specifically Fe and Zn), they need to form ligands with metabolites for transport within the phloem. Current methods available in collecting phloem exudate allows for small volumes (µL or nL) to be collected which limits the breadth of metabolite analysis. We present a technical advance in the measurement of 79 metabolites in as little as 19.5 nL of phloem exudate. This was achieved by using mass spectrometry based, metabolomic techniques. RESULTS: Using gas chromatography-mass spectrometry (GC-MS), 79 metabolites were detected in wheat phloem. Of these, 53 were identified with respect to their chemistry and 26 were classified as unknowns. Using the ratio of ion area for each metabolite to the total ion area for all metabolites, 39 showed significant changes in metabolite profile with a change in wheat reproductive maturity, from 8-12 to 17-21 days after anthesis. Of these, 21 were shown to increase and 18 decreased as the plant matured. An amine group derivitisation method coupled with liquid chromatography MS (LC-MS) based metabolomics was able to quantify 26 metabolites and semi-quantitative data was available for a further 3 metabolites. CONCLUSIONS: This study demonstrates that it is possible to determine metabolite profiles from extremely small volumes of phloem exudate and that this method can be used to determine variability within the metabolite profile of phloem that has occurred with changes in maturity. This is also believed to be the first report of the presence of the important metal complexing metabolite, nicotianamine in the phloem of wheat.