Purpose-In this study, we introduce a methodology for preparing 18 F-labeled Affibody protein, specifically 18 F-Anti-HER2 dimeric Affibody (14 kDa), for in vivo imaging of HER2neu with positron emission tomography (PET). Conclusion-Site-specific 18 F-labeled Affibody against HER2 has been synthesized via chemoselective oxime formation between an aminooxy-functionalized Affibody and 18 Ffluorobenzaldehyde. The results have implications for radiolabeling of other affibodies and macromolecules and should also be important for advancing Affibody imaging with PET.
Procedures-We
Not all amide bonds are created equally. The purpose of the present paper is the reinterpretation of the amide group by means of two concepts: amidicity and carbonylicity. These concepts are meant to provide a new viewpoint in defining the stability and reactivity of amides. With the help of simple quantum-chemical calculations, practicing chemists can easily predict the outcome of a desired process. The main benefit of the concepts is their simplicity. They provide intuitive, but quasi-thermodynamic data, making them a practical rule of thumb for routine use. In the current paper we demonstrate the performance of our methods to describe the chemical character of an amide bond strength and the way of its activation methods. Examples include transamidation, acyl transfer and amide reductions. Also, the method is highly capable for simple interpretation of mechanisms for biological processes, such as protein splicing and drug mechanisms. Finally, we demonstrate how these methods can provide information about photo-activation of amides, through the examples of two caged neurotransmitter derivatives.
Semiochemicals are substances or mixtures that carry messages and are used for communication between individuals of the same or different species. Semiochemicals that are used in pest control are called biopesticides. Conventional pesticides, which are generally synthetically derived and unnatural, inactivate or kill the pests, whereas biopesticides are naturally occurring compounds that attract insects to a trap or interfere with their reproduction.There are several advantages to biopesticides. Compared to conventional pesticides, biochemical-based pesticides are often less toxic and therefore pose a significantly lower impact 2 on human health and the environment. Moreover, the biopesticides are pest selective and as such, do not negatively impact other organisms such as insects, mammals or birds. Other advantages of biopesticides include high potency, meaning that smaller amounts of biopesticide are required, less resistance by target organisms, and the ability to biodegrade more quickly than conventional pesticides. [1][2][3] Although the biochemical-based pesticides are very promising materials, their production is often cumbersome and their application is often limited. So far, most of the biopesticides are synthesized by multistep, classical organic reactions which are not economical and pose high environmental impact. However, in recent decades, many efforts have been done to implement cost-effective and safer chemical procedures for the widespread application of biochemical-based pesticides. The purpose of this perspective is to draw the attention of the green chemistry community to the applicability of olefin metathesis reactions in environmental benign and cost-effective biopesticide synthesis. In this article, we review seminal work on the total synthesis of biopesticides using olefin metathesis as a key reaction step, and in doing so, we hope to inspire new ideas for forthcoming olefin metathesis based biopesticide development.
In order to improve the fluorescence properties of the green fluorescent protein chromophore, p-HOBDI ((5-(4-hydroxybenzylidene)-2,3-dimethyl-3,5-dihydro-4H-imidazol-4-one), sixteen dihydroimidazolone derivates were synthesized from thiohydantoin and arylaldehydes. The synthesis developed is an efficient, novel, one-pot procedure. The study provides a detailed description of the spectroscopic characteristics of the newly synthesized compounds, using p-HOBDI as a reference. The new compounds all exhibited significantly stronger fluorescence than p-HOBDI, up to 28 times higher quantum yields. An experimental and theoretical investigation of the relationship of the fluorescence properties with the molecular structure was also carried out. A good correlation was found between the emission wavenumber and the Hammett constant of the functional group, which suggests the intermolecular charge transfer (ICT) mechanism between the aromatic groups.Graphical abstract *Manuscript Click here to download Manuscript: AJancso_Spectrochimica_A_20181201_V1.pdf Click here to view linked References
Pools of normal tissue cultures were examined for enzymes associated with nucleic acid metabolism. Ribonucleases and desoxyribonucleases, 5-nucleotidases, simple nucleotidases, acid and alkaline phosphatases were studied, and certain others occasionally demonstrated. Characteristic behavior of these enzyme systems during the cultivation procedures, during growth, and during degeneration was described. Quantitative data indicate the presence of significant amounts of enzymes in the supernatant fluid. This accounts for the considerable loss in these specialized constituents during fluid changes. The bearing of these findings on the physiology and pathology of cultivated cells was discussed, as a working hypothesis, with special emphasis on poliomyelitis infection. The use of enzyme assays, as functional tests supplementing morphological methods in tissue cultivation, was recommended.
Cross metatheses
of tung oil, a nonedible vegetable oil and α-eleostearic
acid ((9Z,11E,13E)-octadeca-9,11,13-trienoic acid, ESA) methyl ester (1), obtained from tung oil containing the same highly unsaturated,
conjugated double bonds, have been carried out with cis-1,4-diacetoxy-2-butene (2) using Hoveyda-Grubbs (3-HG2) or Grubbs second or third generation catalysts (3-G2 or 3-G3). The reactions followed by Pd/C-catalyzed
hydrogenation give methyl 11-acetoxyundecanoate (4) as
a polyester raw material, 1,6-diacetoxy-hexane (5) as
a precursor of 1,6-hexanediol (6) polyurethane monomer,
and heptyl acetate as a fragrance (7) in 53–99%
yields after Pd/C-catalyzed hydrogenation. The one-pot isomerization
metathesis of α-linolenic acid ((9Z,12Z,15Z)-9,12,15-octadecatrienoic acid, ALA)
methyl ester (7) using 2 as cross coupling
agent, RuHCl(CO)(PPh3)3 (9) as
isomerization, and 3-G2 as a metathesis catalyst followed
by Pd/C catalyzed hydrogenation leads also to the formation of 5 and the homologues of 4 and 7 in
reasonable yield. Thus, in the latter approach, the key step of the
synthesis of 5 is the one-pot isomerization of the isolated
double bonds of 7 into conjugated ones along the fatty
acid chain in combination with a subsequent cross-metathesis by using
cross-coupling agent 2.
The antioxidant and UV stabilizing effect of different carbon blacks on parafin oil model compound with and without additional stabilizers was investigated. The thermal and photooxistabilities of the samples were characterized by the induction period of the oxygen consumption which was measured volumetrically in a closed system filled with oxygen. A relationship was established between the induction periods of the thermal oxistability curves and the distributions of oxygen content within the active groups of the blacks.
Determining the stabilities of the polymer‐black‐antioxidant systems, synergistic and antagonistic phenomena were observed. These effects were explained by taking nto account the quality and amount of the active sites of the blacks.
The photooxidation experiments corroborated the double role of the black as UV stabilizer. Primarily it acts as a UV screen, its effectiveness being proportional to its specific surface. In addition to this, the synergism and antagonism observed in the ternary systems suggested that the carbon was also involved in the photooxidation as a chain terminating and peroxide decomposing agent.
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