5522-42-9Relevant articles and documents
Sensitive and selective detection of urinary 1-nitropyrene metabolites following administration of a single intragastric dose of diesel exhaust particles (SRM 2975) to rats
Van Bekkum, Yvette M.,Van den Broek, Petra H. H.,Scheepers, Paul T. J.,Bos, Rob P.
, p. 1382 - 1390 (1998)
1-Nitropyrene (1-NP) has been proposed as a marker for exposure to diesel exhaust particles (DEP). Since the extent of the actual intake of 1- NP adsorbed on DEP will be relatively low, sensitive and selective methods are needed regarding human exposure assessment. Two analytical methods are presented for the assessment of 1-NP metabolites in urine of male Sprague- Dawley rats administered a single intragastric dose of native DEP (SRM 2975, 20 rag, 35.7 μg of 1-NP/g). Enzymatically hydrolyzed urine was extracted using Blue Rayon. The extracts were analyzed directly, using HPLC with postcolumn on-line reduction and fluorescence detection (HPLC-Flu), or were processed further for GC/MS/MS analysis. Although sensitive to several metabolites, the HPLC-Flu method lacked selectivity for quantitation of some important metabolites in rat urinary extracts, and therefore seems suitable for screening purposes only. With regard to GC/MS/MS analysis, derivatization with heptafluorobutyrylimidazole (HFBI) yielded low limits of determination for hydroxy-1-aminopyrenes, hydroxy-Nacetyl-1-aminopyrenes (converted to derivatized hydroxy-1-aminopyrenes by the reagent), and 1-aminopyrene (1.8- 9.2 fmol on the column). Derivatization of hydroxy-1-nitropyrenes yielded relatively high limits of determination, and therefore, hydroxy-1- nitropyrenes were reduced to hydroxy-1-aminopyrenes prior to derivatization with HFBI. Intragastric administration of DEP to rats resulted in urinary excretion of 6-hydroxy-N-acetyl-1-aminopyrene, 8-hydroxy-N-acetyl-1- ammopyrene, 6-hydroxy-1-nitropyrene, 8-hydroxy-1-nitropyrene, and 3-hydroxy- 1-nitropyrene (7, 1.2, 1.6, 0.3, and 0.5% of the dose within 12 h, respectively). 1-Nitropyrene, N-acetyl-1-aminopyrene, and 3-, 6-, and 8- hydroxy-1-aminopyrene were not observed as urinary metabolites following administration of a single dose of DEP. The observed excretion pattern and urinary metabolite concentrations suggest that 1-NP present on unmodified DEP becomes bioavailable to a large extent and is metabolized in the same way as was previously observed following administration of pure 1-NP. The presented methods are promising for assessment of human exposure to 1-NP, e.g., following exposure to DEP, because of the possibility of analyzing large volumes of urine, the conversion of three types of metabolites to one (the amino metabolites), and the low detection limits that are achieved.
Preparation and characterization of pyrene modified uridine derivatives as potential electron donors in RNA
Frommer, Jennifer,Karg, Beatrice,Weisz, Klaus,Müller, Sabine
, p. 7663 - 7673 (2018/11/02)
Charge transfer across double stranded DNA was observed for the first time about 20 years ago, and ever since it has been the subject of a large number of studies. RNA has been hardly investigated in this regard, which not least is due to the lack of suitably functionalized ribonucleotide building blocks to serve as electron sources upon incorporation into oligoribonucleotides. We have synthesized two uridine derivatives carrying pyrene or dimethylaminopyrene linked to C5 of the nucleobase. The key to successful synthesis was the adaptation of Suzuki-Miyaura conditions to the coupling of the pyrene moiety with the ribonucleoside. Final decoration of the pyrenylated nucleosides with standard 5′-O- and 2′-O-protecting groups and subsequent 3′-O-phosphitylation delivered the building blocks for incorporation into RNA. Spectroscopic analysis of the two pyrenylated uridines and of the accordingly modified oligonucleotides showed that in particular the dimethyaminopyrene functionalized nucleoside is a promising candidate as an electron source for RNA charge transport studies.
