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Ruobing Chao – One of the best experts on this subject based on the ideXlab platform.
fragmentation study of Aminoalcohol diterpenoid alkaloids by electrospray ionization time of flight mass spectrometryRapid Communications in Mass Spectrometry, 2016Co-Authors: Minghai Tang, Lu Wang, Ruobing ChaoAbstract:
Aminoalcohol-diterpenoid alkaloids were found to be a group of cardioactive substances in the lateral roots of Aconitum carmichaeli Debx. Studies on the fragmentation behaviors and features of these alkaloids in mass spectrometry would be important for their structural identification and in vivo metabolic research, which has not received much attention thus far.
In this study, the fragmentation behaviors of 14 Aminoalcohol-diterpenoid alkaloids were investigated by utilizing high-resolution time-of-flight tandem mass spectrometry. By analysis of the obtained MS2 data, we summarized the fragmentation features of the corresponding alkaloids under different collision energy.
The dissociation of functional groups from the skeleton was observed as the main fragmentation way in electrospray ionization (ESI) mode. The order of fragmentation sites was C1/C3 > C16 > C15 > C6 > N, with loss of one or more CH3OH, H2O, C2H4 (substituent on N atom) or CO (at C15) groups.
The first systematic investigations on the fragmentation of Aminoalcohol-diterpenoid alkaloids are described in this paper, setting the stage for an in-depth identification and study of the corresponding components in complex systems. Copyright © 2015 John Wiley & Sons, Ltd.
simultaneous determination of thirteen Aminoalcohol diterpenoid alkaloids in the lateral roots of aconitum carmichaeli by solid phase extraction liquid chromatography tandem mass spectrometryPlanta Medica, 2014Co-Authors: Jiayu Ding, Dongmei Xiong, Liming Ye, Ruobing ChaoAbstract:
Aminoalcohol-diterpenoid alkaloids have been reported as the cardioactive components in the lateral roots of Aconitum carmichaeli (Fuzi) according to recent studies. Determination of these effective components is of great significance for quality control purposes for Fuzi. Here we report, for the first, the development and validation of a new method to determine the 13 Aminoalcohol-diterpenoid alkaloids in Fuzi by using a simple and accurate solid-phase extraction-liquid chromatography-tandem mass spectrometry. The chromatographic analysis was performed on an ODS column with methanol-0.1 % formic acid (80 : 20, v/v) as the mobile phase. The quantification was performed using MS/MS detection in the positive ion mode with multiple reaction monitoring. Linearity was observed within a range of concentrations of 20–2000 ng/mL. For all the analytes, the r value was greater than 0.9990. The limit of detection and the limit of quantitation were less than 0.5 ng/mL and 2.0 ng/mL, respectively. The intraday and interday precisions were less than 5 % and 10 %, respectively. The accuracy was within the range of 90 to 105 %. This method was successfully applied to determine the 13 Aminoalcohol-diterpenoid alkaloids in Fuzi from different origins and with different processing methods.
Sakayu Shimizu – One of the best experts on this subject based on the ideXlab platform.
directed evolution of an Aminoalcohol dehydrogenase for efficient production of double chiral AminoalcoholsJournal of Bioscience and Bioengineering, 2011Co-Authors: Nobuyuki Urano, Michihiko Kataoka, Takeru Ishige, Shinji Kita, Keiji Sakamoto, Satoko Fukui, Shoko Kumashiro, Sakayu ShimizuAbstract:
Abstract The Aminoalcohol dehydrogenase (AADH) of Rhodococcus erythropolis MAK154, which can be used as a catalyst for the stereoselective reduction of ( S )-1-phenyl-1-keto-2-methylaminopropane to d -pseudoephedrine (dPE), is inhibited by the accumulation of dPE in the reaction mixture, limiting the yield of dPE. To improve this weak point of the enzyme, random mutations were introduced into aadh , and a mutant enzyme library was constructed. The mutant library was screened with a color detectable high-throughput screening method to obtain the evolved enzymes showing the activity in the presence of a high concentration of dPE. Two mutant enzymes showed higher tolerability to dPE than the wild type enzyme. Each of these enzymes had a single amino acid substitution in a different position (G73S and S214R), and a third mutant enzyme carrying both of these amino acid substitutions was constructed. Escherichia coli transformant cells, which express mutant AADHs, showed activity in the presence of 100 mg/ml dPE. A kinetic parameter analysis of the wild type and mutant enzymes was carried out. As compared with the wild type enzyme, the mutant enzymes carrying the S214R amino acid substitution or both the S214R and G73S substitutions showed higher k cat values, and the mutant enzymes carrying the G73S amino acid substitution or both the G73S and S214R substitutions showed higher K m values. These results suggest that the Ser214 residue plays an important role in enzyme activity, and that the Gly73 residue participates in enzyme–substrate binding.
genetic analysis around Aminoalcohol dehydrogenase gene of rhodococcus erythropolis mak154 a putative gntr transcription factor in transcriptional regulationApplied Microbiology and Biotechnology, 2011Co-Authors: Nobuyuki Urano, Michihiko Kataoka, Takeru Ishige, Shinji Kita, Keiji Sakamoto, Sakayu ShimizuAbstract:
NADP+-dependent Aminoalcohol dehydrogenase (AADH) of Rhodococcus erythropolis MAK154 catalyzes the reduction of (S)-1-phenyl-1-keto-2-methylaminopropane ((S)-MAK) to d-pseudoephedrine, which is used as a pharmaceutical. AADH is suggested to participate in Aminoalcohol or aminoketone metabolism in this organism because it is induced by the addition of several Aminoalcohols, such as 1-amino-2-propanol. Genetic analysis of around the aadh gene showed that some open reading frames (ORFs) are involved in this metabolic pathway. Four of these ORFs might form a carboxysome-like polyhedral organelle, and others are predicted to encode aminotransferase, aldehyde dehydrogenase, phosphotransferase, and regulator protein. OrfE, a homologous ORF of the FadR subfamily of GntR transcriptional regulators, lies downstream from aadh. To investigate whether or not orfE plays a role in the regulation of aadh expression, the gene disruption mutant of R. erythropolis MAK154 was constructed. The ΔorfE strain showed higher AADH activity than wild-type strain. In addition, a transformed strain, which harbored multi-orfE, showed no AADH activity even in the induced condition with 1-amino-2-propanol. These results suggest that OrfE is a negative regulator that represses aadh expression in the absence of 1-amino-2-propanol.
Arturo San Feliciano – One of the best experts on this subject based on the ideXlab platform.
long chain Aminoalcohol and diamine derivatives induce apoptosis through a caspase 3 dependent pathwayBioorganic & Medicinal Chemistry Letters, 2002Co-Authors: Esther Del Olmo, Mario Alves, Jose Luis Lopez, Antonio Macho, Fadwa El Banoua, Eduardo Munoz, Arturo San FelicianoAbstract:
Abstract A number of long chain diamines and Aminoalcohols and several of their alkyl, acyl and carbamoyl derivatives, have been synthesized and evaluated for their apoptotic activities using the Jurkat cell line. Apoptosis was measured by flow cytometry and the best results were found for the Aminoalcohols displaying either a free alcohol or an amine with at least, one free hydrogen atom. The apoptotic pathway was mediated by a disruption of the mitochondria transmembrane potential and caspase-3 activation, inducing DNA fragmentation at the phase G 1 /S of the cell cycle.
synthesis and enzyme inhibitory activities of a series of lipidic diamine and Aminoalcohol derivatives on cytosolic and secretory phospholipases a2Bioorganic & Medicinal Chemistry Letters, 2000Co-Authors: Rut Lucas, Esther Del Olmo, Amalia Ubeda, Miguel Paya, Mario Alves, Jose Luis Lopez, Arturo San FelicianoAbstract:
Abstract We have synthesised some lipidic diamines and Aminoalcohols and examined their behaviour as inhibitors of secretory and cytosolic PLA 2 . Some structure–activity relationships considerations have been deduced. Compound 14 Download high-res image (162KB) Download full-size image Scheme 1 . Synthesis of lipidic diamine and Aminoalcohol derivatives. i: a) EtOOCCl/N-methylmorpholine/THF; b) NaBH 4 /MeOH. ii) MsCl/Et 3 N/CH 2 Cl 2 . iii. NaN 3 /DMF. iv. Pd-C/HCCl 3 , NaBH 4 /MeOH. v: EtBr (or EtOOCCH 2 Br)/Et 3 N/DMF. vi: glutaric anhydride/EtOAc. vii: HCl/THF, Argon. viii: BnCl/NaH/DMF. ix: EtBr (1.2 or 2.2 eq.)/Et 3 N/DMF. x: succinic (maleic, glutaric) anh./EtOAc. xi: EtOOCCH 2 Br/Et 3 N. xii: H 2 /Pd-C/AcOH. xiii: 10% KOH/MmeOH. xiv: n -C 6 H 13 COCl ( n -C 15 H 31 COCl)/Et 2 O. xv: TMSCl/PhOH/HCCl 3 . was a potent and selective inhibitor of cPLA 2 and compound 4 showed a dual inhibitory profile against both types of PLA 2 while no cytotoxicity at 10 μM on human neutrophils or on murine macrophage line was observed for both.