Direct synthesis of Fmoc protected amino acid hydroxamates from acid chlorides mediated by magnesium oxide

The synthesis of Fmoc protected amino acid hydroxamates using Fmoc-amino acid chlorides and magnesium oxide is described. The method is simple and efficient, results in complete conversion, and gives good yields and satisfactory purity. © 2003 Elsevier Science Ltd. All rights reserved

Microwave assisted Wolff rearrangement: A facile method for the synthesis of Fmoc-β-amino acids

The Wolff rearrangement of α-diazoketones, derived from Fmoc-α-amino acids, under no base conditions on exposure to microwave irradiation for 40 to 60 sec to Fmoc-β-amino acids with retention of configuration in good yield (91-95%) is described

N-Silylation of amines and amino acid esters under neutral conditions employing TMS-Cl in the presence of zinc dust

An expedient synthetic approach to N-silylamines has been developed. The protocol, using TMS-Cl/zinc dust instead of BSA, is useful for the conversion of amines or amino acid esters to the corresponding silyl derivatives, followed by acylation with an acyl chloride or Fmoc-amino acid chloride to give the corresponding amide or peptide. This procedure, affording products in good to excellent yields, is also efficient for the coupling of sterically hindered amino acids like α,α-dialkylamino acids and NMe-amino acids. Further, the use of an equimolar quantity of organic base, such as Et 3N/pyridine, is circumvented. © 2005 Published by Elsevier Ltd

Primary productivity in the nearshore waters of Vizhinjam, Trivandrum

Primary productivity and related aspects in the Vizhinjam Bay and adjacent open sea were investigated from April 1983 to March 1984. The rate of production was estimated by determining O by the light and dark bottle method. The gross production in Vizhinjam Bay ranged from 114 to 672 mg C/m3/day and in the open sea station it varied from 185 to 739 mgC/m3/day. The range in the net production was from 32 to 429 mg C/m3/day in the Bay and from 114 to 411 mg C/m3/day in the open sea station. High values of phosphate were recorded in September and October in the Bay and during August- November in the open sea. The nitrite and nitrate values were low when compared to those reported earlier from Vizhinjam Bay. The monthly variations in surface production were not significantly related to either temperature or salinity. The correlation between primary production and nutrient concentration was discussed

Fmoc-amino acid azides in peptide synthesis

Fmoc-amino acid azides can be prepared from the corresponding acid chlorides and sodium azide. All the compounds made have been obtained as solids in good yield and purity. They are found to be shelf stable at room temperature for longer periods. Their storage at room temperature does not lead to the formation of isocyanates. Employing them as coupling agents, the synthesis of a few dipeptides is described

On the occurrence of Acanthaster planci (the crown-of-thorns) at Minicoy Atoll.

The predation of coral-polyps by the multi-armed star fish Acanthaster planci is identified during the last two decades as a major biological factor that causes large scale death to reef corals at several parts of the Indo-Pacific. During a recent visit by a team of scientists from Central Marine Fisheries Research Institute,the presence of this star fish in the lagoon of Minicoy Atoll was noticed in November, 1979.Many control measures of star fishes have been practised elsewhere in the Pacific. However, hand-picking of the adults with the aid of pointed spears and killing them with formalin or ammonia solution is the most eifective.Careful search among the corals is required, since the crown-of-thorns hide under the crevices during day time

Zooplankton in relation to hydrography and pelagic fisheries in the inshore waters of Vizhinjam, Trivandrum

The seasonal fluctuations in the total plankton biomass and in the abundance of major zooplankters in the Vizhinjam Bay and the adjacent open sea were studied for two years from February 1980 to January 1982 in relation to the hydrography and the pelagic fisheries of the region. Copepods formed the major component of the zooplankton community for the greater part of the year. The other dominant groups were decapod larvae, cladocerans and chaetognaths. During certain months copepods were outnumbered by cladocerans, which swarmed during monsoon months only. Decapod larvae, appendicularians, fish eggs, fish larvae and Lucifer exhibited a sharp decline during south-west monsoon period. The revival started with the north-east monsoon and these groups attained their peak abundance in different months. The total zooplankton volume did not exhibit significant relationship with any of the hydrographic parameters investigated. The peak periods in the zooplankton biomass were found to coincide with the peak seasons of pelagic fisheries in both the years of collection. The importance of zooplankters in the study of the pelagic ecosystem in general and the fisheries in particular is pointed out

Hydrological features of the Arabian sea off the Northern and central west coast of India During 1964 winter

The hydrographic features prevailing along the northern and central west coast of India during the early part of winter 1964 are discussed. A weak northward gradient in temperature north of 17°N and an eastward gradient south of it is noticed. The thermocline is found at shallower depths in the northern regions. A steady increase in the salinity is observed northward, the maximum being off Bombay. North of 17°N the flow is mainly eastwards which deflects towards south with increase in depth. At SO m a continuous weak southward drift is noticed. More or less uniform distribution is foimd in the dissolved oxygen content at surface and 20 m depth, but at 50 m depth eastward gradients are noticed. Sharp decrease in dissolved oxygen values occur from the top of the thermocline and the oxygen minimum layer is conspicuous in all the sections. The nature of the isotherms and the isolines of oxygen indicate the presence of upwelling in the region off Bombay. The total phosphorus content is much less in the region between 15°N and 18°N with higher values further south and north of these latitudes. The patterns of distribution of dissolved oxygen and total phosphorus contents show an inverse relationship. A westward gradient in the phosphorus values is seen at 50 m depth

Amidated and ibuprofen-conjugated kyotorphins promote neuronal rescue and memory recovery in cerebral hypoperfusion dementia model

Copyright © 2016 Sá Santos, Santos, Pinto, Ramu, Heras, Bardaji, Tavares and Castanho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Chronic brain ischemia is a prominent risk factor for neurological dysfunction and progression for dementias, including Alzheimer's disease (AD). In rats, permanent bilateral common carotid artery occlusion (2VO) causes a progressive neurodegeneration in the hippocampus, learning deficits and memory loss as it occurs in AD. Kyotorphin (KTP) is an endogenous antinociceptive dipeptide whose role as neuromodulator/neuroprotector has been suggested. Recently, we designed two analgesic KTP-derivatives, KTP-amide (KTP-NH2) and KTP-NH2 linked to ibuprofen (IbKTP-NH2) to improve KTP brain targeting. This study investigated the effects of KTP-derivatives on cognitive/behavioral functions (motor/spatial memory/nociception) and hippocampal pathology of female rats in chronic cerebral hypoperfusion (2VO-rat model). 2VO-animals were treated with KTP-NH2 or IbKTP-NH2 for 7 days at weeks 2 and 5 post-surgery. After behavioral testing (week 6), coronal sections of hippocampus were H&E-stained or immunolabeled for the cellular markers GFAP (astrocytes) and NFL (neurons). Our findings show that KTP-derivatives, mainly IbKTP-NH2, enhanced cognitive impairment of 2VO-animals and prevented neuronal damage in hippocampal CA1 subfield, suggesting their potential usefulness for the treatment of dementia.Funding was provided by the Portuguese Agency Fundação para a Ciência e a Tecnologia SFRH/BPD/79542/2011 fellowship)info:eu-repo/semantics/publishedVersio

Even obligate symbioses show signs of ecological contingency: Impacts of symbiosis for an invasive stinkbug are mediated by host plant context

Many species interactions are dependent on environmental context, yet the benefits of obligate, mutualistic microbial symbioses to their hosts are typically assumed to be universal across environments. We directly tested this assumption, focusing on the symbiosis between the sap‐feeding insect Megacopta cribraria and its primary bacterial symbiont Candidatus Ishikawaella capsulata. We assessed host development time, survival, and body size in the presence and absence of the symbiont on two alternative host plants and in the insects\u27 new invasive range. We found that association with the symbiont was critical for host survival to adulthood when reared on either host plant, with few individuals surviving in the absence of symbiosis. Developmental differences between hosts with and without microbial symbionts, however, were mediated by the host plants on which the insects were reared. Our results support the hypothesis that benefits associated with this host–microbe interaction are environmentally contingent, though given that few individuals survive to adulthood without their symbionts, this may have minimal impact on ecological dynamics and current evolutionary trajectories of these partners