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51.
52.
Dubreil-Chéneau E Pirotais Y Bessiral M Roudaut B Verdon E 《Journal of chromatography. A》2011,1218(37):6292-6301
A rapid and reliable LC-MS/MS method for the simultaneous confirmation of twelve non steroidal anti-inflammatory drugs (NSAIDs) in bovine milk was developed and fully validated in accordance with the European Commission Decision 2002/657/EC. The validation scheme was built in accordance with the MRLs or target analytical levels (EU-CRL recommended concentrations and detection capabilities) of the analytes, except for diclofenac for which the lower level of validation achieved was 0.5 μg kg(-1) whereas its MRL is 0.1 μg kg(-1). The NSAIDs investigated were as follows: phenylbutazone (PBZ), oxyphenylbutazone (OPB), naproxen (NP), mefenamic acid (MF), vedaprofen (VDP), flunixin (FLU), 5-hydroxyflunixin (FLU-OH), tolfenamic acid (TLF), meloxicam (MLX), diclofenac (DC), carprofen (CPF) and ketoprofen (KTP). Several extraction procedures had been investigated during the development phase. Finally, the best results were obtained with a procedure using only methanol as the extraction solvent, with an evaporation step included and no further purification. Chromatographic separation was achieved on a C18 analytical column and the run was split in 2 segments. Matrix effects were also investigated. Data acquisition implemented for the confirmatory purpose was performed by monitoring 2 MRM transitions per analyte under the negative electrospray mode. Mean relative recoveries ranged from 94.7% to 110.0%, with their coefficients of variation lying between 2.9% and 14.7%. Analytical limits expressed in terms of decision limits (CCα) were evaluated between 0.69 μg kg(-1) (FLU) and 27.54 μg kg(-1) (VDP) for non-MRL compounds, and at 0.10 (DC), 15.37 (MLX), 45.08 (FLU-OH), and 62.96 μg kg(-1) (TLF) for MRL compounds. The validation results proved that the method is suitable for the screening and confirmatory steps as implemented for the French monitoring plan for NSAID residue control in bovine milk. 相似文献
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54.
Tsutsui H Fujii S Sakamoto T Min JZ Todoroki K Toyo'oka T 《Journal of separation science》2012,35(13):1551-1559
Mass spectrometry (MS) has become a popular analytical technique because of its high sensitivity and specificity. Therefore, the use of a chiral derivatization reagent for the MS detection seems to be efficient for the enantiomeric separation of racemates. However, the number of chiral reagents for the liquid chromatography (LC)-tandem mass spectrometry (MS/MS) analysis is very limited. The applicability of commercially available chiral amines as the derivatization reagents for the enantiomeric separation of chiral carboxylic acids is reported in this paper by using non-steroidal anti-inflammatory drugs (NSAIDs), i.e. ibuprofen, flurbiprofen, and loxoprofen. The efficiency of the chiral reagents was evaluated in terms of tagging easiness, separation by reversed-phase chromatography, and detection sensitivity by electrospray ionization (ESI)-MS/MS. Among the tested eight chiral amines, i.e. (R)-(+)-4-(3-aminopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole (DBD-APy), (S)-(+)-1-(2-pyrrolidinylmethyl)-pyrrolidine (PMP), L-prolinamide, (3R)-(-)-1-benzyl-3-aminopyrrolidine, (S)-(+)-1-cyclohexyl-ethylamine, (3R)-(+)-3-(trifluoroacetamido)-pyrrolidine (TFAP), (R)-(-)-1-aminoindan (AI), and (S)-(+)-tetrahydrofurfuryl-amine, DBD-APy, PMP, AI, and TFAP could be used as the chiral reagents for the enantiomeric separation of the NSAIDs. The Rs values and the detection limits of the derivatives were in the range of 1.29-3.85 and 0.57-0.96 fmol, respectively. These four reagents were applied for the determination of the NSAIDs in rat plasma. 相似文献
55.
Gabriel G. Jimnez Alexandra G. Durn Francisco A. Macías Ana M. Simonet 《Molecules (Basel, Switzerland)》2021,26(17)
Yucca is one of the main sources of steroidal saponins, hence different extracts are commercialized for use as surfactant additives by beverage, animal feed, cosmetics or agricultural products. For a deeper understanding of the potential of the saponins that can be found in this genus, an exhaustive review of the structural characteristics, bioactivities and analytical methods that can be used with these compounds has been carried out, since there are no recent reviews on the matter. Thus, a total of 108 saponins from eight species of the genus Yucca have been described. Out of these, the bioactivity of 68 saponins derived from the isolation of Yucca or other genera has been evaluated. Regarding the evaluation and quality control of the saponins from this genus LC-MS technique is the most often used. Nevertheless, the development of methods for their routine analysis in commercial preparations are needed. Moreover, most of the studies found in the literature have been carried out on Y. schidigera extract, since is the most often used for commercial purposes. Only eight of the 50 species that belong to this genus have been studied, which clearly indicates that the identification of saponins present in Yucca genus is still an unresolved question. 相似文献
56.
The phytochemical investigation of the whole plant of Polygonatum multiflorum resulted in the isolation of two new steroidal glycosides, polmultoside A (4) and polmultoside B (5), along with three known glycosides protobioside (1), protodeltonin (2) and huangjiangsu A (3). The structures of the isolated compounds have been elucidated by extensive 1D (1H, 13C) and 2D (COSY, HSQC, HMBC) NMR spectral data analysis, as well as high-resolution mass determinations. 相似文献
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58.
Sayaka Matsushita Yukio Fujiwara Masateru Ono Toshihiro Nohara 《Tetrahedron letters》2005,46(20):3549-3551
Two novel reactions with regard to steroidal alkaloid sapogenols obtained from ripe tomato have been found. These reactions have been attained by simple facile method in only refluxing with pyridine and water. One is isomerization of a spirosolane derivative, isoesculeogenin A (2), into a rare solanocapsine derivative, esculeogenin B (3), disclosing a chemical correlation between isoesculeogenin A and esculeogenin B. Another is conversion of a 23-hydroxyspirosolane derivative, esculeogenin A (1), into a pregnane derivative (4), presenting an epoch-making method for derivation of steroidal hormone material. 相似文献
59.
Mira S. Bjelakovi? Natalija M. Krsti? Milan M. Dabovi? Martin Kessler Vladimir D. Pavlovi? 《Tetrahedron》2007,63(40):9960-9969
We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-OtBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic function) of the steroid nucleus via amide bonds, starting from 18-cyanopregnenolone acetate over 10 steps. In an attempt to gain more insight into the structural and conformational features of this novel 18-Phe,19-Gly-containing steroidal compound, we describe the detailed 2D NMR spectral analysis. Despite the large size and the conformational flexibility of the amino acid units in this molecule, conformational analysis by NOESY connectivities showed the existence of mainly one conformation (∼95%) in CDCl3 solution with approximately parallel orientation of the phenylalanine and glycine moieties. 相似文献
60.
E. A. Dikusar V. I. Potkin N. G. Kozlov S. K. Petkevich N. V. Kovganko 《Chemistry of Natural Compounds》2006,42(3):254-258
Previously undescribed 2-bromo-3,4,4-trichlorobut-3-enoates 1b-23b were synthesized in 84–91% yield from natural alcohols including terpenes and steroids, plant phenols, and oximes of natural
carbonyl compounds 1a-23a by reaction of 2-bromo-3,4,4-trichlorobut-3-enoyl chloride in the presence of pyridine.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 212–215, May–June, 2006. 相似文献