Studies of the ADP/ATP carrier of mitochondria with fluorescent ADP analogue formycin diphosphate

The ADP/ATP carrier was studied by a fluorescent substrate, formycin diphosphate which is the only fluorescent ADP analogue to bind. Its low quantum yield, short decay time and spectral overlap with tryptophan has as yet prevented its wider use.By incorporating fluorescent acceptors of formycin diphosphate fluorescence, anthracene-maleimide and vinylanthracene, into the membrane, these difficulties were circumvented. Only bound formycin diphosphate transfers energy to the probes so that the secondary emission of these probes is a measure for membrane-bound formycin diphosphate.The fluorescent transfer is inhibited by ADP, bongkrekate and carboxy-atractylate whether added before or after incubation of formycin diphosphate showing that only binding to the adenine nucleotide carrier is measured. It also shows directly that the earlier demonstrated ADP fixation by bongkrekate is indeed a displacement into the matrix.The fluorescence decay time of the bound formycin diphosphate is measured as 1.95 ns compared to 0.95 ns of the free formycin diphosphate, indicating that formycin diphosphate is bound at the carrier in a non-polar environment.The depolarization decay time was found to be larger than 15 ns, indicating that carrier-bound formycin diphosphate is immobile within this time period.     

Synthesis and anti-inflammatory activity of sulfonamides and carboxylates incorporating trimellitimides: Dual cyclooxygenase/carbonic anhydrase inhibitory actions

Trimellitimides 6–21 were prepared and investigated in vivo for anti-inflammatory and ulcerogenic effects and in vitro for cytotoxicity. They were subjected to in vitro cyclooxygenase (COX-1/2) and carbonic anhydrase inhibition protocols. Compounds 6–11 and 18 exhibited anti-inflammatory activities and had median effective doses (ED₅₀) of 34.3–49.8 mg kg⁻¹ and 63.6–86.6% edema inhibition relative to the reference drug celecoxib (ED₅₀: 33.9 mg kg⁻¹ and 85.2% edema inhibition). Compounds 6–11 and 18 were weakly cytotoxic at 10 μM against 59 cell lines compared with the reference standard 5-fluorouracil (5-FU). Compounds 6–11 had optimal selectivity against COX-2. The selectivity index (SI) range was >200–490 and was comparable to that for celecoxib [COX-2 (SI) > 416.7]. In contrast, compounds 12, 13, and 16–18 were nonselective COX inhibitors with a selectivity index range of 0.92–0.25. The carbonic anhydrase inhibition assay showed that sulfonamide incorporating trimellitimides 6–11 inhibited the cytosolic isoforms hCA I and hCA II, and tumor-associated isoform hCA IX. They were relatively more susceptible to inhibition by compounds 8, 9, and 11. The K_I ranges were 54.1–81.9 nM for hCA I, 25.9–55.1 nM for hCA II, and 46.0–348.3 nM for hCA IX. © 2018 Elsevier Science. All rights reserved.     

Flavonols and 4-thioflavonols as potential acetylcholinesterase and butyrylcholinesterase inhibitors: Synthesis,structure-activity relationship and molecular docking studies

To explore new scaffolds for the treat of Alzheimer’s disease appears to be an inspiring goal. In this context, a series of varyingly substituted flavonols and 4-thioflavonols have been designed and synthesized efficiently. All the newly synthesized compounds were characterized unambiguously by common spectroscopic techniques (IR, ¹H-, ¹³C NMR) and mass spectrometry (EI-MS). All the derivatives (1–24) were evaluated in vitro for their inhibitory potential against cholinesterase enzymes. The results exhibited that these derivatives were potent selective inhibitors of acetylcholinesterase (AChE), except the compound 11 which was selective inhibitor of butyrylcholinesterase (BChE), with varying degree of IC₅₀ values. Remarkably, the compounds 20 and 23 have been found the most potent almost dual inhibitors of AChE and BChE amongst the series with IC₅₀ values even less than the standard drug. The experimental results in silico were further validated by molecular docking studies in order to find their binding modes with the active pockets of AChE and BChE enzymes.     

1,4-Dihydroquinazolin-3(2H)-yl benzamide derivatives as anti-inflammatory and analgesic agents with an improved gastric profile: Design,synthesis, COX-1/2 inhibitory activity and molecular docking study

The design and synthesis of a new series of 1,4-dihydroquinazolin-3(2H)-yl benzamide derivatives (4a–o) as anti-inflammatory and analgesic agents and COX-1/2 inhibitors are reported. The target compounds (4a–o) were synthesized using a two-step scheme, and their chemical structures were confirmed with ¹H NMR, ¹³C NMR, and mass spectra and elemental analysis. Compounds 4b, 4d, 4h, 4l, 4n and 4o showed the best in vitro COX-2 inhibitory activity (IC₅₀ 0.04–0.07 μM), which was nearly the same as that of the reference drug celecoxib (IC₅₀ 0.049 μM), but had a lower selectivity index, as dictated in our target design. In the in vivo anti-inflammatory inhibition assay, compounds 4b, 4c, 4e, 4f, 4m and 4o showed better oedema inhibition percentages, ranging from 38.1% to 54.1%, than did diclofenac sodium (37.8%). An in vivo analgesic assay revealed that compounds 4b and 4n had a potential analgesic effect 4- to 21-fold more potent than that of indomethacin and diclofenac sodium. All the tested compounds showed an improved ulcerogenic index when compared to indomethacin. In the synthesized series, compound 4b showed the best biological activity in all the experiments. The docking study results agreed with the in vitro COX inhibition assay results. Moreover, the predicted in silico studies of all the compounds support their potential as drug candidates.     

Counter transport of glutamine and choline in cultures of human glioma cells.

Tritiated glutamine and choline were released from human glioma cells in culture when incubated in permeant-free solution. Counter transport experiments revealed that the two neurotransmitter precursors were taken up and released by facilitated diffussion transport systems. It is suggested that glial cells $\text{in}\text{vivo}$ can provide neurons with glutamine and choline for transmitter synthesis via such systems.     

Early life environment determines the development of adult phobic‐like fear responses in BALB/cAnN mice

Environmental factors may unleash genetically determined susceptibility to psychopathology. Great effort has been spent in identifying both the genetic basis and environmental sources of exaggerated fear in animal models of anxiety disorders. Here, we show that the origin of inbred mice, probably via subtle differences in breeding and rearing conditions, may have large consequences specifically on acquisition and retention of fear memories, while leaving anxiety‐related behaviours unaffected. These effects could be seen in BALB/cAnN (BALB), but not in C57BL/6N (C57BL/6) mice, thus suggesting their dependency on the genetic background. Increased susceptibility for developing exaggerated fear responses was accompanied by decreased long‐term depression and increased surface trafficking of the AMPA receptor GluR1 subunit at the level of the basolateral amygdala complex. Together, these data raise a novel caveat in the debate about the origins of variation in behavioural studies with experimental animals. Considering that there are currently no animal models which explicitly consider conceptual analogy to the specific gene–environment interactions observed in the aetiology of phobias, our study might suggest a novel approach and direction for further preclinical studies focusing on such aspects of phobic‐like fears.