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Jalilzadeh, Mohammad,Pesyan, Nader Noroozi Korean Chemical Society 2011 대한화학회지 Vol.55 No.6
Reaction of 1-methylpyrimidine-(1H,3H,5H)-2,4,6-trione (1-MBA 1) as an unsymmetrical barbituric acid with cyanogen bromide and various aldehydes in the presence of triethylamine and/or pyridine afforded diastereomeric mixtures of new class of heterocyclic stable 5-aryl-1,1'-dimethyl- and 5-aryl-3,1'-dimethyl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones which are dimeric forms of 1-methyl barbiturate at the range of $0^{\circ}C$ to room temperature. In the reaction of some aldehydes with 1-MBA and BrCN were afforded a mixture of diastereomers. Another two aldehydes such as 4-cyano- and 2-hydroxybenzaldehydes gave exclusively two diastereomers in which binded to the salt of triethylammonium hydrobromide by intermolecular H-bond in ratio of 1:1. 4-Hydroxybenzaldehyde and 2-pyridinecarbaldehyde gave exclusively one diastereomer under the same condition. Aldehydes possessing strong electron-donor were produced exclusively two geometric isomers of Knoevenagel adduct (E- and Z-isomers). The structures of compounds were deduced by $^1H$ NMR, $^{13}C$ NMR and FT-IR spectroscopy. Mechanism of the formation is discussed.
Ju-Il Sung,Ngoc Van Thi Nguyen,Min-Jung Park,Seung-Beom Lee,Yong-Jae Lee,Seung-Ho Choi,김경호 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.9
Stereoisomers of nadolol were derivatized with S-(-)-menthyl chloroformate((-)-MCF) forming their diastereomers, RSR-nadolol-(-)-MCF, SRS-nadolol-(-)-MCF, RRS-nadolol-(-)-MCF and SSRnadolol-(-)-MCF. Diastereomeric mixture were then chromatographically resolved by preparative HPLC (JAIGEL-ODS-BP-L, 500 × 25 mm column) eluted with methanol-water (84:16, v/v) at flow rate 2.5 mL/min. RSR-nadolol-(-)-MCF diastereomer was hydrolyzed with 5% LiOH at 80oC for 48 h, and the decomposed mixture was further purified by semi-preparative HPLC. The purity and final yield of RSR-nadolol were 99.97% and 12.95%, respectively.
Determination of Silymarin and Silybin Diastereomers in Korean Milk Thistle using HPLC/UV Analysis
김주리,레오 아드리안 바헤,최중원,이학동,심재석,심지형,폴 존 헤랄디노,이상현 한국생약학회 2020 생약학회지 Vol.51 No.4
Silymarin (SM) and silybin diastereomers (SD) in milk thistle (Silybum marianum) were determined using high-performance liquid chromatography and quantified using a reverse-phase column in a gradient elution system. UV detection was performed at 288 nm. The content of SM and SD in milk thistle was 3.236 and 0.553 mg/g DW, respectively. Determining the presence and quantifying the content of SM and SD in milk thistle are vital for the pharmaceutical industry to identify optimal sources for developing health supplements or therapeutics.
D체와 R체 이성질체 판별과 GC-MS를 이용한 유전성 대사이상질환의 진단법 개발
윤혜란,Yoon, Hye-Ran 대한유전성대사질환학회 2015 대한유전성대사질환학회지 Vol.15 No.2
Since the secretion of specific chiral isomers in urine (or plasma) is very crucial to diagnose some inborn metabolic disorders, clinical application of dual column achiral differential method has been performed for the absolute configuration of chiral compounds. Extracted from the acidified urine with diethyl ether, carboxylic functional group of organic acid (stereoisomers of the volatile) was derivatized with (-)-menthylation or (S)-(+)-3-methyl-2-butylation and followed by O-trifluoroacylation. Each of the enantiomers was accurately separated from the library matched double column (achiral) with a retention index (I). In various inborn metabolic disease urines, absolute chirality was identified correctly in the urine (10 patients) with inborn metabolic disease (including secretion of D, L- lactic acid, D, L-3-hydroxybutyric acid, and D, L-2-hydroxyglutaric acid). In this study, we identified and isolated the volatile diastereomer as a useful diagnostic marker, this successful application to urine specimens may be useful for diagnostic classification of inherited metabolic disorders.
Alam, Md. Shameul,Katayama, Takeshi,Suzuki, Toshisada,Sultana, Deeder,Sultana, Saima,Hossain, Md. Daud The Korean Society of Crop Science 2008 Journal of crop science and biotechnology Vol.11 No.1
Lignans and neolignans are optically active plant secondary metabolites. Research on biosynthesis of lignans has already been advanced especially for the formation of (+) pinoresinol but information on the biosynthesis of 8-O-4'- neolignans is still limited. Moreover, the chemical structure(position of substituents on aromatic rings) and stereochemistry of 8-O-4' neolignans is not clear. Katayama and Kado discovered that incubation of cell-free extracts from E. ulmoides with coniferyl alcohol in the presence of hydrogen peroxide gave (+)-erythro- and (-)-threo- guaiacylglycerol 8-O-4'-(coniferyl alcohol) ether (GGCE)(diastereomeric ratio, 3:2) which is the first report on enzymatic formation of optically active -8-O-4' neolignans from an achiral monolignol. In this aspect, enzymatic formation of guaiacyl 8-O-4' neolignan is noteworthy to clarify its stereochemistry from incubation of coniferyl alcohol with enzyme prepared from Eucommia ulmoides. In this experiment, soluble and insoluble enzymes prepared from E. ulmoides were incubated with 30 mM coniferyl alcohol(CA) for 60 min. The enzyme catalyzed GGCE, dehydrodiconiferyl alcohol(DHCA), and pinoresinol identified by reversed phase HPLC. Consequently, diastereomeric compositions of GGCE were determined as erythro and threo isomer. Enantiomeric composition was determined by the chiral column HPLC. Both enzyme preparations enantioselectively formed (-)-erythro, (+)-erythro and (+)-threo, (-)-threo-GGCEs respectively.
Md. Shameul Alam,Takeshi Katayama,Toshisada Suzuki,Deeder Sultana,Saima Sultana,Md. Daud Hossain 한국작물학회 2008 Journal of crop science and biotechnology Vol.11 No.1
Lignans and neolignans are optically active plant secondary metabolites. Research on biosynthesis of lignans has already been advanced especially for the formation of (+) pinoresinol but information on the biosynthesis of 8-O-4´- neolignans is still limited. Moreover, the chemical structure (position of substituents on aromatic rings) and stereochemistry of 8-O-4´ neolignans is not clear. Katayama and Kado discovered that incubation of cell-free extracts from E. ulmoides with coniferyl alcohol in the presence of hydrogen peroxide gave (+)-erythro- and (-)-threo- guaiacylglycerol 8-O-4´-(coniferyl alcohol) ether (GGCE) (diastereomeric ratio, 3:2) which is the first report on enzymatic formation of optically active -8-O-4´ neolignans from an achiral monolignol. In this aspect, enzymatic formation of guaiacyl 8-O-4´ neolignan is noteworthy to clarify its stereochemistry from incubation of coniferyl alcohol with enzyme prepared from Eucommia ulmoides. In this experiment, soluble and insoluble enzymes prepared from E. ulmoides were incubated with 30 mM coniferyl alcohol (CA) for 60 min. The enzyme catalyzed GGCE, dehydrodiconiferyl alcohol (DHCA), and pinoresinol identified by reversed phase HPLC. Consequently, diastereomeric compositions of GGCE were determined as erythro and threo isomer. Enantiomeric composition was determined by the chiral column HPLC. Both enzyme preparations enantioselectively formed (-)-erythro, (+)-erythro and (+)-threo, (-)-threo-GGCEs respectively. Lignans and neolignans are optically active plant secondary metabolites. Research on biosynthesis of lignans has already been advanced especially for the formation of (+) pinoresinol but information on the biosynthesis of 8-O-4´- neolignans is still limited. Moreover, the chemical structure (position of substituents on aromatic rings) and stereochemistry of 8-O-4´ neolignans is not clear. Katayama and Kado discovered that incubation of cell-free extracts from E. ulmoides with coniferyl alcohol in the presence of hydrogen peroxide gave (+)-erythro- and (-)-threo- guaiacylglycerol 8-O-4´-(coniferyl alcohol) ether (GGCE) (diastereomeric ratio, 3:2) which is the first report on enzymatic formation of optically active -8-O-4´ neolignans from an achiral monolignol. In this aspect, enzymatic formation of guaiacyl 8-O-4´ neolignan is noteworthy to clarify its stereochemistry from incubation of coniferyl alcohol with enzyme prepared from Eucommia ulmoides. In this experiment, soluble and insoluble enzymes prepared from E. ulmoides were incubated with 30 mM coniferyl alcohol (CA) for 60 min. The enzyme catalyzed GGCE, dehydrodiconiferyl alcohol (DHCA), and pinoresinol identified by reversed phase HPLC. Consequently, diastereomeric compositions of GGCE were determined as erythro and threo isomer. Enantiomeric composition was determined by the chiral column HPLC. Both enzyme preparations enantioselectively formed (-)-erythro, (+)-erythro and (+)-threo, (-)-threo-GGCEs respectively.