Mietek Mieczysław Sajewicz

Prof. Dr. Mietek Mieczysław Sajewicz


Research Focus & Metrics

Academic Career Length

39Years (1988-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 September 2017 in Forensic Toxicology
Verified
Journal Article
Open access
PDF file
MMMilena Majchrzak
Milena Majchrzak
RCRafał Celiński
Rafał Celiński
PKPiotr Kuś
Piotr Kuś
TKTeresa Kowalska
Teresa Kowalska
MSMietek Mieczysław Sajewicz
Mietek Mieczysław Sajewicz
Purpose Currently, among new psychoactive substances, cathinone derivatives constitute the biggest group, which are mainly classified into N-alkylated, 3,4-methylenedioxy-N-alkylated, N-pyrrolidinyl, and 3,4-methylenedioxy-N-pyrrolidinyl derivatives. These derivatives are actively being subjected to minor modifications at the alkyl chains or the aromatic ring to create new synthetic cathinones with the goal of circumventing laws. In this review, the new synthetic cathinones that have appeared on the illegal drug market during the period 2014–2017 are highlighted, and their characterization by gas chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry is presented. Methods Various key words were used to conduct an extensive literature search across a number of databases, specifically for synthetic cathinones that emerged between 2014 and 2017. Results More than 30 new cathinone derivatives were discovered. The preexisting parental compounds for the new derivatives are also referenced, and their mass spectral data are compiled in a table to facilitate their identification by forensic toxicologists. Conclusions To our knowledge, this is the most current review presenting new synthetic cathinones. Political authorities should take measures to implement and enforce generic scheduling (comprehensive system) laws to control the diversely modified synthetic cathinones. Supplementing the existing databases with new findings can greatly facilitate the efforts of forensic toxicologists.

1 December 2008 in Acta Chromatographica
Verified
Journal Article
Closed access
PPPaweł Paśko
Paweł Paśko
MSMietek Mieczysław Sajewicz
Mietek Mieczysław Sajewicz
SGS. Gorinstein
S. Gorinstein
ZZZ. Zachwieja
Z. Zachwieja

5 October 2022 in Molecules
Verified
Journal Article
Open access
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TKTeresa Kowalska
Teresa Kowalska
MSMietek Mieczysław Sajewicz
Mietek Mieczysław Sajewicz
The aim of this paper is to present a comprehensive overview of the main aims and scopes in screening of botanicals, a task of which thin-layer chromatography (TLC) is, on an everyday basis, confronted with and engaged in. Stunning omnipresence of this modest analytical technique (both in its standard format (TLC) and the high-performance one (HPTLC), either hyphenated or not) for many analysts might at a first glance appear chaotic and random, with an auxiliary rather than leading role in research, and not capable of issuing meaningful final statements. Based on these reflections, our purpose is not to present a general review paper on TLC in screening of botanicals, but a blueprint rather (illustrated with a selection of practical examples), which highlights a sovereign and important role of TLC in accomplishing the following analytical tasks: (i) solving puzzles related to chemotaxonomy of plants, (ii) screening a wide spectrum of biological properties of plants, (iii) providing quality control of herbal medicines and alimentary and cosmetic products of biological origin, and (iv) tracing psychoactive plants under forensic surveillance.

12 August 2013 in Molecules
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Journal Article
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Robert D. WojtyczkaRobert D. Wojtyczka
Robert D. Wojtyczka
Arkadiusz DziedzicArkadiusz Dziedzic
Arkadiusz Dziedzic
DIDanuta Idzik
Danuta Idzik
KMKępa Małgorzata
Kępa Małgorzata
Robert KubinaRobert Kubina
Robert Kubina
Tomasz J. WąsikTomasz J. Wąsik
Tomasz J. Wąsik
The objective of this study was to assess in vitro the antimicrobial activity of ethanolic extract of Polish propolis (EEPP) against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. The combined effect of EEPP and 10 selected antistaphylococcal drugs on S. aureus clinical cultures was also investigated. EEPP composition was analyzed by a High Performance Liquid Chromatography (HPLC) method. The flavonoid compounds identified in Polish Propolis included flavones, flavonones, flavonolols, flavonols and phenolic acids. EEPP displayed varying effectiveness against twelve S. aureus strains, with minimal inhibitory concentration (MIC) within the range from 0.39 to 0.78 mg/mL, determined by broth microdilution method. The average MIC was 0.54 ± 0.22 mg/mL, while calculated MIC50 and MIC90 were 0.39 mg/mL and 0.78 mg/mL, respectively. The minimum bactericidal concentration (MBC) of the EEPP ranged from 0.78 to 3.13 mg/mL. The in vitro combined effect of EEPP and 10 antibacterial drugs was investigated using disk diffusion method-based assay. Addition of EEPP to cefoxitin (FOX), clindamycin (DA), tetracycline (TE), tobramycin (TOB), linezolid (LIN), trimethoprim+sulfamethoxazole (SXT), penicillin (P), erythromycin (E) regimen, yielded stronger, cumulative antimicrobial effect, against all tested S. aureus strains than EEPP and chemotherapeutics alone. In the case of ciprofloxacin (CIP) and chloramphenicol (C) no synergism with EEPP was observed.

16 October 2014 in PLOS ONE
Verified
Journal Article
Open access
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Maciej SerdaMaciej Serda
Maciej Serda
DKDanuta S Kalinowski
Danuta S Kalinowski
NRNathalie Rasko
Nathalie Rasko
EPEliška Potůčková
Eliška Potůčková
AMAnna Mrozek-Wilczkiewicz
Anna Mrozek-Wilczkiewicz
Jaroslaw PolanskiJaroslaw Polanski
Jaroslaw Polanski
Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized “soft” donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination.

1 January 2018 in Journal of Chromatography A
Verified
Journal Article
Closed access
AMAgnes M. Moricz
Agnes M. Moricz
DSDariusz Szeremeta
Dariusz Szeremeta
MKMagdalena Knaś
Magdalena Knaś
EDEwa Długosz
Ewa Długosz
POPéter G. Ott
Péter G. Ott
MSMietek Mieczysław Sajewicz
Mietek Mieczysław Sajewicz