The methods of determination of 6-methyl coumarin in cosmetics by HPLC-DAD and GC-FID were compared. The positive samples were confirmed by GC-MS. Methanol was used to extract 6-methyl coumarin from cosmetics. The chr...The methods of determination of 6-methyl coumarin in cosmetics by HPLC-DAD and GC-FID were compared. The positive samples were confirmed by GC-MS. Methanol was used to extract 6-methyl coumarin from cosmetics. The chromatographic conditions of the two methods were optimized and the samples were determined. The recovery, precision, correlation coefficient, detection limit and quantitative limit of the two methods were compared. The results showed that the linear relationship between the two methods was good. The percentage recovery of standard addition by HPLC-DAD was 92.20%~102.80%, by RSD was 0.77%~2.00%;the detection limit was 0.05 mg/kg, the quantitative limit was 0.17 mg/kg. The percentage recovery of standard addition by GC-FID was 97.30%~103.28%, by RSD was 0.47%~4.87%;the detection limit was 1.3 mg/kg, the quantitative limit was 5.0 mg/kg. The detection limit by HPLC-DAD was lower and more sensitive than that by GC-FID , which also shows that HPLC-DAD has more advantages for the detection of low content samples.展开更多
Ethyl 3,9-dihydroxy-9-methyl-7-phenyl-7,8,10-trihydro-6H-dibenzo[b,d]pyran-6-one-8-carboxylate（C（23）H（22）O6,Mr = 394.42） has been synthesized and its structure was determined by ~1H and ^（13）C NMR,ESI-MS,eleme...Ethyl 3,9-dihydroxy-9-methyl-7-phenyl-7,8,10-trihydro-6H-dibenzo[b,d]pyran-6-one-8-carboxylate（C（23）H（22）O6,Mr = 394.42） has been synthesized and its structure was determined by ~1H and ^（13）C NMR,ESI-MS,elemental analysis,and X-ray single-crystal diffraction.The crystal belongs to the triclinic system,space group P1,with a = 8.8220（17）,b = 9.881（2）,c = 12.157（2） A,α= 90.488（3）,β= 102.664（4）,γ= 98.799（3）°,V= 1020.8（3） A^3,Z= 2,Dc = 1.342 g/cm^3,μ= 0.099mm^（-1）,F（000） = 436,R = 0.0615 and wR = 0.2501 for 2592 observed reflections with（I2σ（I））.In the crystal structure,the coumarin ring system is planar and the 3：4 fused cyclohexane ring adopts distorted half-chair conformation.Rich hydrogen bonding interactions are formed between compound 2 and lattice water molecules.These interactions assemble molecules of 2 into 2D layered networks in an AB stacking sequence.Its in vitro antiproliferative activities against three human cancer cell lines were evaluated by MTT assay.展开更多
A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out...A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.展开更多
Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacteriz...Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacterized.Here,we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing.Found in 0.1%of adenines,6mA sites are mostly enriched at the AGGYV motif,more abundant in transposons and 30 untranslated re-gions,and associated with active transcription.Moreover,6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcrip-tion termination sites.Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes,indicating a positive interaction between 6mA and general transcription fac-tors.Furthermore,knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor,sulfate transporter,glycosyl transferase,and lipase genes that underlie reductions in biomass and oil productivity.By contrast,knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth.Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.展开更多
文摘The methods of determination of 6-methyl coumarin in cosmetics by HPLC-DAD and GC-FID were compared. The positive samples were confirmed by GC-MS. Methanol was used to extract 6-methyl coumarin from cosmetics. The chromatographic conditions of the two methods were optimized and the samples were determined. The recovery, precision, correlation coefficient, detection limit and quantitative limit of the two methods were compared. The results showed that the linear relationship between the two methods was good. The percentage recovery of standard addition by HPLC-DAD was 92.20%~102.80%, by RSD was 0.77%~2.00%;the detection limit was 0.05 mg/kg, the quantitative limit was 0.17 mg/kg. The percentage recovery of standard addition by GC-FID was 97.30%~103.28%, by RSD was 0.47%~4.87%;the detection limit was 1.3 mg/kg, the quantitative limit was 5.0 mg/kg. The detection limit by HPLC-DAD was lower and more sensitive than that by GC-FID , which also shows that HPLC-DAD has more advantages for the detection of low content samples.
基金the financial support from the Natural Science Foundation of Jiangsu University of Technologythe Provincial Key Project of Natural Science Research for Colleges and Universities of Anhui Province(KJ2014A062)
文摘Ethyl 3,9-dihydroxy-9-methyl-7-phenyl-7,8,10-trihydro-6H-dibenzo[b,d]pyran-6-one-8-carboxylate（C（23）H（22）O6,Mr = 394.42） has been synthesized and its structure was determined by ~1H and ^（13）C NMR,ESI-MS,elemental analysis,and X-ray single-crystal diffraction.The crystal belongs to the triclinic system,space group P1,with a = 8.8220（17）,b = 9.881（2）,c = 12.157（2） A,α= 90.488（3）,β= 102.664（4）,γ= 98.799（3）°,V= 1020.8（3） A^3,Z= 2,Dc = 1.342 g/cm^3,μ= 0.099mm^（-1）,F（000） = 436,R = 0.0615 and wR = 0.2501 for 2592 observed reflections with（I2σ（I））.In the crystal structure,the coumarin ring system is planar and the 3：4 fused cyclohexane ring adopts distorted half-chair conformation.Rich hydrogen bonding interactions are formed between compound 2 and lattice water molecules.These interactions assemble molecules of 2 into 2D layered networks in an AB stacking sequence.Its in vitro antiproliferative activities against three human cancer cell lines were evaluated by MTT assay.
基金the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials for financial support(No.JSKC07041).
文摘A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.
基金supported by the Synthetic Biology Program of the Ministry of Science and Technology of the People’s Republic of China (2021YFA0909700)I201908 and E1551402 from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences,31900071 from the Natural Science Foundation of ChinaZR2019QC012 from the Natural Science Foundation of Shandong Province.
文摘Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacterized.Here,we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing.Found in 0.1%of adenines,6mA sites are mostly enriched at the AGGYV motif,more abundant in transposons and 30 untranslated re-gions,and associated with active transcription.Moreover,6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcrip-tion termination sites.Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes,indicating a positive interaction between 6mA and general transcription fac-tors.Furthermore,knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor,sulfate transporter,glycosyl transferase,and lipase genes that underlie reductions in biomass and oil productivity.By contrast,knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth.Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.
