(3R, 9S, 10S)-Heptadec-1-ene-4,6-diyne-3, 9, 10-triol 2, a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template, through the Cadiot-Chodkiczwicz coupling of the terminal...(3R, 9S, 10S)-Heptadec-1-ene-4,6-diyne-3, 9, 10-triol 2, a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template, through the Cadiot-Chodkiczwicz coupling of the terminal acetylene 3 with bromoacetylene 4.展开更多
α-fructofuranosides were stereospecifically synthesized from 2-O-Ac-1,3,4,6-O-tetra-benzoylfructose by employing TMSOTf as a catalyst. Meanwhile,one diastereoisomer derivative of sucrose and two of fructan oligomers ...α-fructofuranosides were stereospecifically synthesized from 2-O-Ac-1,3,4,6-O-tetra-benzoylfructose by employing TMSOTf as a catalyst. Meanwhile,one diastereoisomer derivative of sucrose and two of fructan oligomers were synthesized.The structure of all products were confirmed by ^(13)C-NMR and ~1H-NMR spectra.展开更多
Equol is a metabolite of soybean isoflavone, daidzein, and many health benefits are expected. Endogenous equol in urine is S-equol and mostly exists as glucuronate or sulfate conjugate. In this study we preliminary es...Equol is a metabolite of soybean isoflavone, daidzein, and many health benefits are expected. Endogenous equol in urine is S-equol and mostly exists as glucuronate or sulfate conjugate. In this study we preliminary established the simple enzyme-linked immunosorbent assay (ELISA) without deconjugation, then developed the S-equol specific ELISA involves deconjugation showing high stereospecificity to S-equol without using stereospecific antibody. For the simple ELISA, we used a polyclonal antibody that targets the regions not influenced by inhibition by conjugation of glucuronate and sulfate and achieved the correlation coefficient;r = 0.975, but the value was 30 % lower than high performance liquid chromatography (HPLC). Developing upon this we invented the specific ELISA established from S-equol homogeneous combination for the standard and enzyme-labeled antigen to enhance stereospecificity. The correlation with HPLC was favorable: r = 0.986, y = 0.996x – 6. Compared to the previous method using (R,S)-equol combination, cross-reactivity with R-equol was reduced from 65 to 13 %, and that with daidzein from 0.31% to 0.08%, markedly increased in the specificity. This study is expected to be applied for both simple clinical researches, and stereospecific immunoassays in which specific antibody preparation is difficult.展开更多
Hexabromocyclododecane(HBCD) is an effective brominated flame-retardant additive, which is mainly produced in the coastal area of China. This study collected soil samples from a HBCD production plant and its surroundi...Hexabromocyclododecane(HBCD) is an effective brominated flame-retardant additive, which is mainly produced in the coastal area of China. This study collected soil samples from a HBCD production plant and its surrounding area in Weifang, Shandong Province, China, and analyzed the temporal–spatial distribution of HBCD and its diastereoisomers in soil. The analysis results showed that the concentration of HBCD in soil near the plant was much higher than normal values, with an annual average concentration reaching 5405 ng/g. Soils 1,2 and 4 km away from the plant were also analyzed, showing that the concentration of HBCD in soil decreased accordingly with the distance from the pollution sources. In order to investigate the effect of the season on HBCD content, the soil samples were collected in all four seasons of the year 2017–2018. According to variations in the wind direction, the concentration of HBCD in soil was also changed. The distribution trend showed that the concentration of HBCD in soil in the downwind direction of the prevailing wind was higher than that in the upwind direction. In addition, this work analyzed the distribution of HBCD in vertical soil sections. It was found that the concentration of HBCD decreased with depth in the soil vertical profile. Finally, the various diastereoisomer patterns in the soil compartments were examined, finding that α-HBCD and γ-HBCD were the predominant diastereoisomers in the soil of the study area.展开更多
Yingzhaosu D (1), coexisting with Yingzhaosu A (2) which is an antimalarial principlein a traditional Chinese herbal medicine Yingzhao (Artabotrys uncinatus L. Merr.), has shownto be a new polyhydroxy sesquiterpene. W...Yingzhaosu D (1), coexisting with Yingzhaosu A (2) which is an antimalarial principlein a traditional Chinese herbal medicine Yingzhao (Artabotrys uncinatus L. Merr.), has shownto be a new polyhydroxy sesquiterpene. We have previously reported the synthesis of Ying-zhaosu A (2) and shown that the configuration at C-4 is S. It is therefore reasonable to as-sume that the corresponding carbon atom in Yingzhaosu D has the same absolute configura-tion. Herein we report an effective method to prepare Yingzhaosu D and its three stereo-展开更多
A new kind of hydrazone (I) diastereoisomers was prepared with enantiomeric hydazide (II) and chiral cluster (III), which was characterized by HMBC. Unfortunately, the mixture could not be separated into pure diastere...A new kind of hydrazone (I) diastereoisomers was prepared with enantiomeric hydazide (II) and chiral cluster (III), which was characterized by HMBC. Unfortunately, the mixture could not be separated into pure diastereoisomer. This could be a direction to separate the racemic chiral clusters.展开更多
Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensiv...Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensive spectroscopic analyses, X-ray diffraction and quantum molecular calculation. Their plausible biogenetic pathway featured an intriguing carbonyl-ene cyclization. Lithocarpinol A exhibited moderate inhibitory effect against HepG-2 and A549 tumor cell lines with IC_(50) values of 9.4 μmol/L and10.9 μmol/L,respectively.展开更多
Chiral recognition of phenylalanine(Phe) was achieved in the gas phase by electrospray ionization Q-TOF tandem mass spectrometry.In this method,two central ions,i.e.proton and divalent copper,were used and chiral crow...Chiral recognition of phenylalanine(Phe) was achieved in the gas phase by electrospray ionization Q-TOF tandem mass spectrometry.In this method,two central ions,i.e.proton and divalent copper,were used and chiral crown ether,(+)-2,3,11,12-tetracarboxylic acid-18-crown-6(18-C-6-TCA),was used as a chiral host.Dimeric complexes were readily formed by electrospray ionization of a methanol/water(50/50,V/V) solution containing central ions,Phe and 18-C-6-TCA.The dimeric complex included proton-bound(18-C-6-TCA)(Phe)H+ and copper-bound deprotonated [Cu2+(18-C-6-TCA)(Phe)-H]+ ions were mass selected and then collided with Ar in the CID experiments.The chiral recognition capability of these complexes was evaluated using the relative abundance of daughter ion to parent ion.A higher degree of chiral recognition ability was observed with Cu2+ compared to that of H+.Different central ions exhibited distinctive dissociation pathways and unique chiral recognition characteristics.The chiral recognition mechanism was also discussed in detail with the help of the structure of copper-bound complex predicted by theoretical calculation.展开更多
文摘(3R, 9S, 10S)-Heptadec-1-ene-4,6-diyne-3, 9, 10-triol 2, a diastereoisomer of panaxytriol 1 was synthesized using L-(+)-diethyl tartrate 5 as a chiral template, through the Cadiot-Chodkiczwicz coupling of the terminal acetylene 3 with bromoacetylene 4.
文摘α-fructofuranosides were stereospecifically synthesized from 2-O-Ac-1,3,4,6-O-tetra-benzoylfructose by employing TMSOTf as a catalyst. Meanwhile,one diastereoisomer derivative of sucrose and two of fructan oligomers were synthesized.The structure of all products were confirmed by ^(13)C-NMR and ~1H-NMR spectra.
文摘Equol is a metabolite of soybean isoflavone, daidzein, and many health benefits are expected. Endogenous equol in urine is S-equol and mostly exists as glucuronate or sulfate conjugate. In this study we preliminary established the simple enzyme-linked immunosorbent assay (ELISA) without deconjugation, then developed the S-equol specific ELISA involves deconjugation showing high stereospecificity to S-equol without using stereospecific antibody. For the simple ELISA, we used a polyclonal antibody that targets the regions not influenced by inhibition by conjugation of glucuronate and sulfate and achieved the correlation coefficient;r = 0.975, but the value was 30 % lower than high performance liquid chromatography (HPLC). Developing upon this we invented the specific ELISA established from S-equol homogeneous combination for the standard and enzyme-labeled antigen to enhance stereospecificity. The correlation with HPLC was favorable: r = 0.986, y = 0.996x – 6. Compared to the previous method using (R,S)-equol combination, cross-reactivity with R-equol was reduced from 65 to 13 %, and that with daidzein from 0.31% to 0.08%, markedly increased in the specificity. This study is expected to be applied for both simple clinical researches, and stereospecific immunoassays in which specific antibody preparation is difficult.
基金financial support received from the National Natural Science Foundation of China(No.20977094)the Science and Technology Development Plan Projects of Weifang(No.2014ZJ1055)
文摘Hexabromocyclododecane(HBCD) is an effective brominated flame-retardant additive, which is mainly produced in the coastal area of China. This study collected soil samples from a HBCD production plant and its surrounding area in Weifang, Shandong Province, China, and analyzed the temporal–spatial distribution of HBCD and its diastereoisomers in soil. The analysis results showed that the concentration of HBCD in soil near the plant was much higher than normal values, with an annual average concentration reaching 5405 ng/g. Soils 1,2 and 4 km away from the plant were also analyzed, showing that the concentration of HBCD in soil decreased accordingly with the distance from the pollution sources. In order to investigate the effect of the season on HBCD content, the soil samples were collected in all four seasons of the year 2017–2018. According to variations in the wind direction, the concentration of HBCD in soil was also changed. The distribution trend showed that the concentration of HBCD in soil in the downwind direction of the prevailing wind was higher than that in the upwind direction. In addition, this work analyzed the distribution of HBCD in vertical soil sections. It was found that the concentration of HBCD decreased with depth in the soil vertical profile. Finally, the various diastereoisomer patterns in the soil compartments were examined, finding that α-HBCD and γ-HBCD were the predominant diastereoisomers in the soil of the study area.
基金Project supported by the National Natural Science Foundation of China.
文摘Yingzhaosu D (1), coexisting with Yingzhaosu A (2) which is an antimalarial principlein a traditional Chinese herbal medicine Yingzhao (Artabotrys uncinatus L. Merr.), has shownto be a new polyhydroxy sesquiterpene. We have previously reported the synthesis of Ying-zhaosu A (2) and shown that the configuration at C-4 is S. It is therefore reasonable to as-sume that the corresponding carbon atom in Yingzhaosu D has the same absolute configura-tion. Herein we report an effective method to prepare Yingzhaosu D and its three stereo-
基金We are grate ful to the National Natural Science Foundation of China for the f inancial support of this work.
文摘A new kind of hydrazone (I) diastereoisomers was prepared with enantiomeric hydazide (II) and chiral cluster (III), which was characterized by HMBC. Unfortunately, the mixture could not be separated into pure diastereoisomer. This could be a direction to separate the racemic chiral clusters.
基金financially supported by the Science and Technology Program of Guangzhou, China(No. 201607020018)the Team Project of the Natural Science Foundation of Guangdong Province (No. 2016A030312014)+2 种基金the National Natural Science Foundation of China (No. 31272087)the Guangdong Provincial Project for Science and Technology (Nos. 2015A030302061, 2016A020222022)the Guangdong Provincial Innovative Development of Marine Economy Regional Demonstration Projects (No. GD2012-D01-002)
文摘Lithocarpinols A(1) and B(2), a pair of tenellone diastereoisomers with novel fused skeleton were isolated from the deep-sea derived fungus Phomopsis lithocarpus FS508. Their structures were elucidated by comprehensive spectroscopic analyses, X-ray diffraction and quantum molecular calculation. Their plausible biogenetic pathway featured an intriguing carbonyl-ene cyclization. Lithocarpinol A exhibited moderate inhibitory effect against HepG-2 and A549 tumor cell lines with IC_(50) values of 9.4 μmol/L and10.9 μmol/L,respectively.
文摘Chiral recognition of phenylalanine(Phe) was achieved in the gas phase by electrospray ionization Q-TOF tandem mass spectrometry.In this method,two central ions,i.e.proton and divalent copper,were used and chiral crown ether,(+)-2,3,11,12-tetracarboxylic acid-18-crown-6(18-C-6-TCA),was used as a chiral host.Dimeric complexes were readily formed by electrospray ionization of a methanol/water(50/50,V/V) solution containing central ions,Phe and 18-C-6-TCA.The dimeric complex included proton-bound(18-C-6-TCA)(Phe)H+ and copper-bound deprotonated [Cu2+(18-C-6-TCA)(Phe)-H]+ ions were mass selected and then collided with Ar in the CID experiments.The chiral recognition capability of these complexes was evaluated using the relative abundance of daughter ion to parent ion.A higher degree of chiral recognition ability was observed with Cu2+ compared to that of H+.Different central ions exhibited distinctive dissociation pathways and unique chiral recognition characteristics.The chiral recognition mechanism was also discussed in detail with the help of the structure of copper-bound complex predicted by theoretical calculation.
