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Budapest, Hungary

Balazs A.,Ubichem Research Ltd. | Hunyadi A.,University of Szeged | Csabi J.,University of Szeged | Jedlinszki N.,University of Szeged | And 4 more authors.
Magnetic Resonance in Chemistry

The synthesis, structure elucidation and the complete 1H and 13C signal assignment of a series of dioxolane derivatives of 20-hydroxyecdysone, synthesized as novel modulators of multidrug resistance, are presented. The structures and NMR signal assignment were established by comprehensive one-dimensional and two-dimensional NMR spectroscopy supported by mass spectrometry. Copyright © 2013 John Wiley & Sons, Ltd. Source

Martins A.,University of Szeged | Martins A.,New University of Lisbon | Csabi J.,University of Szeged | Balazs A.,Ubichem Research Ltd. | And 6 more authors.

Ecdysteroids, molting hormones of insects, can exert several mild, non-hormonal bioactivities in mammals, including humans. In a previous study, we have found a significant effect of certain derivatives on the ABCB1 transporter mediated multi-drug resistance of a transfected murine leukemia cell line. In this paper, we present a structure-activity relationship study focused on the apolar dioxolane derivatives of 20-hydroxyecdysone. Semi-synthesis and bioactivity of a total of 32 ecdysteroids, including 20 new compounds, is presented, supplemented with their complete 1H- and 13C-NMR signal assignment. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Zsoter Z.,Debrecen University | Timar T.,Ubichem Research Ltd. | Konya K.,Debrecen University | Patonay T.,Debrecen University | Jeka J.,SunPharma Ltd.
Journal of Heterocyclic Chemistry

4,4-Dimethylchromeno[4,3-d]selenadiazoles 8 with insecticide activities have been synthesized via oxidative ring closure of the corresponding semicarbazone derivatives 7 by treatment with selenium dioxide. Reaction of various alkoxy-2,2-dimethyl-2H-benzopyrans with phenylselenyl chloride was utilized to prepare different phenylselenyl- and 3-chloro precocene analogs. © 2014 HeteroCorporation. Source

Shariatgorji M.,Uppsala University | Nilsson A.,Uppsala University | Goodwin R.J.A.,Uppsala University | Goodwin R.J.A.,Astrazeneca | And 7 more authors.
Analytical Chemistry

D4-α-Cyano-4-hydroxycinnamic acid (D4-CHCA) has been synthesized for use as a matrix for matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) and MALDI-MS imaging (MSI) of small molecule drugs and endogenous compounds. MALDI-MS analysis of small molecules has historically been hindered by interference from matrix ion clusters and fragment peaks that mask signals of low molecular weight compounds of interest. By using D4-CHCA, the cluster and fragment peaks of CHCA, the most common matrix for analysis of small molecules, are shifted by + 4, + 8 and + 12 Da, which expose signals across areas of the previously concealed low mass range. Here, obscured MALDI-MS signals of a synthetic small molecule pharmaceutical, a naturally occurring isoquinoline alkaloid, and endogenous compounds including the neurotransmitter acetylcholine have been unmasked and imaged directly from biological tissue sections. © 2012 American Chemical Society. Source

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