Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffractio...Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.展开更多
Carbon quantum dots(CQDs)are fluorescent carbon nanomaterials that have been applied to biology,medicine,and optoelectronics,owing to their significant advantages such as simple synthesis methods,low cost,and widely a...Carbon quantum dots(CQDs)are fluorescent carbon nanomaterials that have been applied to biology,medicine,and optoelectronics,owing to their significant advantages such as simple synthesis methods,low cost,and widely available sources of raw synthesis materials.This review summarizes CQD preparation methods,which include hydrothermal and microwave-assisted synthesis methods,as well as separation methods such as centrifugation,dialysis,and filtration.Additionally,we review the application of CQDs in the detection of active ingredients,primarily phenolic compounds,in traditional Chinese medicine.We also discuss the quenching mechanism of CQD fluorescence using the active ingredients of traditional Chinese medicine.Limitations such as insufficient test selectivity,weak fluorescence intensity,and an unclear quantitative relationship between preparation methods and properties should be resolved for the efficient use of CQDs to detect active ingredients in Chinese medicine.展开更多
文摘Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.
基金supported by the National S&T Major Project of China(2018ZX09201011-003)the National Project for Standardization of Chinese Materia Medica(ZYBZH-C-GD-04).
文摘Carbon quantum dots(CQDs)are fluorescent carbon nanomaterials that have been applied to biology,medicine,and optoelectronics,owing to their significant advantages such as simple synthesis methods,low cost,and widely available sources of raw synthesis materials.This review summarizes CQD preparation methods,which include hydrothermal and microwave-assisted synthesis methods,as well as separation methods such as centrifugation,dialysis,and filtration.Additionally,we review the application of CQDs in the detection of active ingredients,primarily phenolic compounds,in traditional Chinese medicine.We also discuss the quenching mechanism of CQD fluorescence using the active ingredients of traditional Chinese medicine.Limitations such as insufficient test selectivity,weak fluorescence intensity,and an unclear quantitative relationship between preparation methods and properties should be resolved for the efficient use of CQDs to detect active ingredients in Chinese medicine.
