目的对肾茶(Clerodendranthus spicatus(Thunb)C Y Wu ex H.W.Li)地上部分的化学成分进行研究,进一步丰富其物质基础。方法采用加热回流提取法对肾茶的干燥地上部分进行提取,联合应用硅胶、ODS及高效液相色谱等多种色谱法对肾茶地上部...目的对肾茶(Clerodendranthus spicatus(Thunb)C Y Wu ex H.W.Li)地上部分的化学成分进行研究,进一步丰富其物质基础。方法采用加热回流提取法对肾茶的干燥地上部分进行提取,联合应用硅胶、ODS及高效液相色谱等多种色谱法对肾茶地上部分提取物的化学成分进行分离纯化,结合圆二色光谱、核磁、质谱等波谱技术以及化学反应的方法,鉴定化合物的结构,确定其绝对构型。结果从肾茶地上部分分离鉴定了7个丹参素衍生物,分别为(R)-迷迭香酸(1)、(R)-迷迭香酸甲酯(2)、(R)-迷迭香酸乙酯(3)、2R-羟基-3-(4-羟基苯基)丙酸甲酯(4)、2R-羟基-3-(3,4-二羟基苯基)丙酸(5)、2R-羟基-3-(3,4-二羟基苯基)丙酸甲酯(6)和2R-羟基-3-(3,4-二羟基苯基)丙酸乙酯(7)。结论化合物4为首次从肾茶属植物中分离得到。此外,发现对于α-羟基羧酸类化合物,即使是只有一个手性中心,也不能仅仅通过旋光值的比对确定其绝对构型。本文所提供的方法为该类成分构型的研究提供了借鉴。展开更多
As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor Os...As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor OsbZIP01,which can suppress the expression of SD1 and regulate gibberellin(GA)biosynthesis in rice.Knockout mutants of OsbZIP01 exhibited increased plant height,while the overexpression lines showed a semi-dwarf phenotype and diminished germination rate.Furthermore,the semi-dwarf phenotype of OE-bZIP01,was caused by the reduced internode length,which was accompanied by a thin stem width.The predominant expression of OsbZIP01 was observed in leaves and sheaths.OsbZIP01 protein was localized in the nucleus and showed transcriptional repression activity.In addition,OsbZIP01 could directly bind to the promoter of the OsSD1 gene,and inhibit its transcription.The semi-dwarf phenotype of OE-bZIP01 could be rescued by exogenous GA_(3).Meanwhile,the bzip01 sd1 double mutant showed a shorter shoot length compared with the wild type,indicating that OsbZIP01 regulated plant growth mainly through the GA biosynthesis pathway.Collectively,OsbZIP01 negatively regulates GA biosynthesis by restraining SD1 transcription,thereby affecting plant growth and development.展开更多
A simplex centroid design method was employed to design the gradation of recycled coarse aggregate.The bulk density was measured while the specific surface area and average excess paste thickness were calculated with ...A simplex centroid design method was employed to design the gradation of recycled coarse aggregate.The bulk density was measured while the specific surface area and average excess paste thickness were calculated with different gradations.The fluidity,dynamic yield stress,static yield stress,printed width,printed inclination,compressive strength and ultrasonic wave velocity of 3D printed recycled aggregate concrete(3DPRAC)were further studied.The experimental results demonstrate that,with the increase of small-sized aggregate(4.75-7 mm)content,the bulk density initially increases and then decreases,and the specific surface area gradually increases.The average excess paste thickness fluctuates with both bulk density and specific surface area.The workability of 3DPRAC is closely related to the average excess paste thickness.With an increase in average paste thickness,there is a gradual decrease in dynamic yield stress,static yield stress and printed inclination,accompanied by an increase in fluidity and printed width.The mechanical performance of 3DPRAC closely correlates with the bulk density.With an increase in the bulk density,there is an increase in the ultrasonic wave velocity,accompanied by a slight increase in the compressive strength and a significant decrease in the anisotropic coefficient.Furthermore,an index for buildability failure of 3DPRAC based on the average excess paste thickness is proposed.展开更多
文摘目的对肾茶(Clerodendranthus spicatus(Thunb)C Y Wu ex H.W.Li)地上部分的化学成分进行研究,进一步丰富其物质基础。方法采用加热回流提取法对肾茶的干燥地上部分进行提取,联合应用硅胶、ODS及高效液相色谱等多种色谱法对肾茶地上部分提取物的化学成分进行分离纯化,结合圆二色光谱、核磁、质谱等波谱技术以及化学反应的方法,鉴定化合物的结构,确定其绝对构型。结果从肾茶地上部分分离鉴定了7个丹参素衍生物,分别为(R)-迷迭香酸(1)、(R)-迷迭香酸甲酯(2)、(R)-迷迭香酸乙酯(3)、2R-羟基-3-(4-羟基苯基)丙酸甲酯(4)、2R-羟基-3-(3,4-二羟基苯基)丙酸(5)、2R-羟基-3-(3,4-二羟基苯基)丙酸甲酯(6)和2R-羟基-3-(3,4-二羟基苯基)丙酸乙酯(7)。结论化合物4为首次从肾茶属植物中分离得到。此外,发现对于α-羟基羧酸类化合物,即使是只有一个手性中心,也不能仅仅通过旋光值的比对确定其绝对构型。本文所提供的方法为该类成分构型的研究提供了借鉴。
基金supported by the National Natural Science Foundation of China(Grant No.32101763)China National Postdoctoral Program for Innovative Talents(Grant No.BX2021266)China Postdoctoral Science Foundation(Grant No.2021M692853).
文摘As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor OsbZIP01,which can suppress the expression of SD1 and regulate gibberellin(GA)biosynthesis in rice.Knockout mutants of OsbZIP01 exhibited increased plant height,while the overexpression lines showed a semi-dwarf phenotype and diminished germination rate.Furthermore,the semi-dwarf phenotype of OE-bZIP01,was caused by the reduced internode length,which was accompanied by a thin stem width.The predominant expression of OsbZIP01 was observed in leaves and sheaths.OsbZIP01 protein was localized in the nucleus and showed transcriptional repression activity.In addition,OsbZIP01 could directly bind to the promoter of the OsSD1 gene,and inhibit its transcription.The semi-dwarf phenotype of OE-bZIP01 could be rescued by exogenous GA_(3).Meanwhile,the bzip01 sd1 double mutant showed a shorter shoot length compared with the wild type,indicating that OsbZIP01 regulated plant growth mainly through the GA biosynthesis pathway.Collectively,OsbZIP01 negatively regulates GA biosynthesis by restraining SD1 transcription,thereby affecting plant growth and development.
基金Funded by the National Natural Science Foundation of China(No.U1904188)。
文摘A simplex centroid design method was employed to design the gradation of recycled coarse aggregate.The bulk density was measured while the specific surface area and average excess paste thickness were calculated with different gradations.The fluidity,dynamic yield stress,static yield stress,printed width,printed inclination,compressive strength and ultrasonic wave velocity of 3D printed recycled aggregate concrete(3DPRAC)were further studied.The experimental results demonstrate that,with the increase of small-sized aggregate(4.75-7 mm)content,the bulk density initially increases and then decreases,and the specific surface area gradually increases.The average excess paste thickness fluctuates with both bulk density and specific surface area.The workability of 3DPRAC is closely related to the average excess paste thickness.With an increase in average paste thickness,there is a gradual decrease in dynamic yield stress,static yield stress and printed inclination,accompanied by an increase in fluidity and printed width.The mechanical performance of 3DPRAC closely correlates with the bulk density.With an increase in the bulk density,there is an increase in the ultrasonic wave velocity,accompanied by a slight increase in the compressive strength and a significant decrease in the anisotropic coefficient.Furthermore,an index for buildability failure of 3DPRAC based on the average excess paste thickness is proposed.
