Determination of ketamine in rabbit plasma by gradient elution liquid chromatography/electrospray mass spectrometry

A sensitive and simple liquid chromatography/electrospray mass spectrometry (LC-ESI-MS) method for determination of ketamine in rabbit plasma using one-step protein precipitation was developed and validated. After addition of methadone as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographically separation was achieved on an SB-C18 (2.1 mm × 50 mm, 3.5 μm) column with methanol-0.1 % formic acid as the mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 237.7 → 219.7 for ketamine and m/z 309.9 → 264.8 for the IS. Calibration plots were linear over the range of 5-1000 ng/mL for ketamine in rabbit plasma. Lower limit of quantification (LLOQ) for ketamine was 5 ng/mL. Mean recovery of ketamine from plasma was in the range of 97.5-100.1 %. RSD of intra-day and inter-day precision were both less than 11 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of ketamine in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of ketamine in rabbit plasma by gradient elution liquid chromatography/electrospray mass spectrometry

A sensitive and simple liquid chromatography/electrospray mass spectrometry (LC-ESI-MS) method for determination of ketamine in rabbit plasma using one-step protein precipitation was developed and validated. After addition of methadone as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographically separation was achieved on an SB-C18 (2.1 mm × 50 mm, 3.5 μm) column with methanol-0.1 % formic acid as the mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 237.7 → 219.7 for ketamine and m/z 309.9 → 264.8 for the IS. Calibration plots were linear over the range of 5-1000 ng/mL for ketamine in rabbit plasma. Lower limit of quantification (LLOQ) for ketamine was 5 ng/mL. Mean recovery of ketamine from plasma was in the range of 97.5-100.1 %. RSD of intra-day and inter-day precision were both less than 11 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of ketamine in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of ibudilast in rabbit plasma by liquid chromatography-mass spectrometry and its application

A sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method for determination of ibudilast in rabbit plasma was developed and validated. After addition of estazolam as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation, and chromatography involved Agilent SB-C18 column (2.1 mm x 50 mm, 3.5 μm) using 0.1 % formic acid in water and acetonitrile as a mobile phase with gradient elution. Detection involved positive ion mode electrospray ionization (ESI), and selective ion monitoring (SIM) mode was used for quantification of target fragment ions m/z 230.7 for ibudilast and m/z 294.7 for estazolam (internal standard, IS). The assay was linear over the range of 20-2000 ng/mL for ibudilast, with a lower limit of quantitation (LLOQ) of 20 ng/mL for ibudilast. Intra- and inter-day precisions were less than 15 % and the accuracies were in the range of 90.78 %- 105.60 % for ibudilast. This developed method was successfully applied for the determination of ibudilast in rabbit plasma for pharmacokinetic studyColegio de Farmacéuticos de la Provincia de Buenos Aire

Genetic analysis of Penthorum chinense Pursh by improved RAPD and ISSR in China

Background: Penthorum chinense Pursh (P. chinense) is a well-known traditional Chinese medicine (TCM) plant, which has long been used for the prevention and treatment of hepatic diseases. This study aimed to genetically characterize the varieties of P. chinense from different geographic localities of China by random amplification of polymorphic DNA (RAPD)-PCR technique and verified with inter-simple sequence repeat (ISSR) markers. Results: The P. chinense samples were collected from nine different geographic localities. Previously improved RAPD and ISSR markers were utilized for genetic analysis using DNA amplification. The genetic relationship dendrogram was obtained by conducting cluster analysis to the similarity coefficient of improved RAPD and ISSR markers. Improved RAPD yielded 185 scorable amplified products, of which 68.6% of the bands were polymorphic, with an average amplification of 9.25 bands per primer. The ISSR markers revealed 156 alleles with 7.8 bands per primers, where 59.7% bands were polymorphic. Furthermore, the similarity coefficient ranges of RAPD and ISSR markers were 0.71\u20130.91 and 0.66\u20130.89, respectively. Conclusions: This study indicated that improved RAPD and ISSR methods are useful tools for evaluating the genetic diversity and characterizing P. chinense. Our findings can provide the theoretical basis for cultivar identification, standardization, and molecular-assisted breeding of P. chinense for medicinal use

Genetic Identification and Molecular Modeling Characterization Reveal a Novel PROM1 Mutation in Stargardt4-like Macular Dystrophy

Stargardt disease-4 (STGD4) is an autosomal dominant complex, genetically heterogeneous macular degeneration/dystrophy (MD) disorder. In this paper, we used targeted next generation sequencing and multiple molecular dynamics analyses to identify and characterize a disease-causing genetic variant in four generations of a Chinese family with STGD4-like MD. We found a novel heterozygous missense mutation, c.734T\u3eC (p.L245P) in the PROM1 gene. Structurally, this mutation most likely impairs PROM1 protein stability, flexibility, and amino acid interaction network after changing the amino acid residue Leucine into Proline in the basic helix-loop-helix leucine zipper domain. Molecular dynamic simulation and principal component analysis provide compelling evidence that this PROM1 mutation contributes to disease causativeness or susceptibility variants in patients with STGD4-like MD. Thus, this finding defines new approaches in genetic characterization, accurate diagnosis, and prevention of STGD4-like MD

Genome-Wide Identification and Analysis of Lipases in Fig Wasps (Chalcidoidea, Hymenoptera)

Lipases are the main enzymes involved in lipid metabolism. However, the characteristics of lipases in insects were scarcely investigated. Here, we screened the recently sequenced genomes of 12 fig wasp species consisting of seven pollinator fig wasps (PFWs) and five non-pollinating fig wasps (NPFWs) for the six major lipase gene families. In total, 481 lipase genes were identified, and the two most numerous families were the neutral and acid lipases. Tandem duplication accounted for the expansion of the gene family. NPFWs had significantly more lipases than PFWs. A significant gene family contraction occurred in the clade of PFWs. The difference of lipases between NPFWs and PFWs might contribute to their distinction in life histories and feeding regimes. Phylogenetic analysis showed that the lipase genes of each fig wasp species was almost equally distributed in each clade, indicating that the lipase genes were conserved. The gene structures were similar within each clade, while they were different among clades. Most of the neutral and acid lipases were signal peptides and located extracellularly. The pathways of lipases involved were predicted. This genome-wide study provides a systematic analysis of lipase gene families in 12 hymenopteran insects and further insights towards understanding the potential functions of lipases

Methyl Jasmonate Changes the Composition and Distribution Rather than the Concentration of Defence Compounds : a Study on Pyrrolizidine Alkaloids

In this study we investigated the effect of methyl jasmonate (MeJA) application on pyrrolizidine alkaloid (PA) concentration and composition of two closely related Jacobaea species. In addition, we examined whether MeJA application affected herbivory of the polyphagous leaf feeding herbivore Spodoptera exigua. A range of concentrations of MeJA was added to the medium of Jacobaea vulgaris and J. aquatica tissue culture plants grown under axenic conditions. PA concentrations were measured in roots and shoots using LC-MS/MS. In neither species MeJA application did affect the total PA concentration at the whole plant level. In J. vulgaris the total PA concentration decreased in roots but increased in shoots. In J. aquatica a similar non-significant trend was observed. In both Jacobaea species MeJA application induced a strong shift from senecionine- to erucifoline-like PAs, while the jacobine- and otosenine-like PAs remained largely unaffected. The results show that MeJA application does not necessarily elicits de novo synthesis, but rather leads to PA conversion combined with reallocation of certain PAs from roots to shoots. S. exigua preferred feeding on control leaves of J. aquatica over MeJA treated leaves, while for J. vulgaris both the control and MeJA treated leaves were hardly eaten. This suggests that the MeJA-induced increase of erucifoline-like PAs can play a role in resistance of J. aquatica to S. exigua. In J. vulgaris resistance to S. exigua may already be high due to the presence of jacobine-like PAs or other resistance factors.</p