Ratiometric fluorescence assay based on carbon dots and Cu2+-catalyzed oxidation of O-phenylenediamine for the effective detection of deferasirox.

The monitoring of deferasirox (DEF) has important clinical roles in patients who need iron excretion. However, analytical methods with practicability and simplicity are limited. Moreover, ratiometric fluorescence strategies based on Förster resonance energy transfer (FRET) from carbon dots (CDs) as a donor are rarely reported as a drug monitor. In this work, CDs with an appropriate emitting wavelength at 480 nm and excitation around 370 nm were prepared by hydrothermal approach and HCl post-treatment. O-Phenylenediamine (OPD) can be oxidized by Cu2+ to produce yellow fluorescent 2,3-diaminophenazine (oxOPD) in the system of Cu2+ and OPD (Cu-OPD). Correspondingly, a remarkable FRET from CDs to oxOPD in the system of CDs, Cu2+ and OPD (CDs-Cu-OPD) was fabricated with the quenching illustration of CDs, but emitting property of oxOPD. Attributed to the chelation ability of DEF on Cu2+, the inhibitory effects of DEF on the Cu2+-triggered oxidative capability reduced the FRET system by the decreased oxOPD. Thus, the recovered CDs at F 480 and decreased oxOPD at F 560 were found through a ratiometric mode by the addition of DEF in CDs-Cu-OPD for the DEF assay. The FRET behavior of CDs and oxOPD in CDs-Cu-OPD was proved clearly through the calculation of the association constant, binding constant, number of binding sites, and the distance between the donor and acceptor. Furthermore, this ratiometric method exhibited promising analytical performance for DEF with the application in real samples. The implementation of this work expands the application field of CDs and OPD oxidation in drug monitoring, and even other biological analyses through ratiometric strategy.

[Quality evaluation methods for standard decoction of Nelumbinis Folium].

The quality evaluation method for standard decoction of Chinese herbal slices is the basis for the quality evaluation of granules and preparations of classical formula(decoction)of traditional Chinese medicine. This study aimed to establish a method for the determination of quercetin-3-O-glucuronic acid in Nelumbinis Folium(NF)and its standard decoction, so as to provide reference for the quality control of NF and its standard decoction. Fifteen batches of representative NF were collected to prepare standard decoction, and the parameters of dry extract rate, transfer rate of index component, and pH value were calculated. HPLC was used to establish the content determination method for quercetin-3-O-glucuronic acid in NF and its standard decoction. The concentration range of quercetin-3-O-glucuronic acid in the standard decoction of NF was 1.09-3.06 g·L~(-1), while the concentration range of nuciferine was 0.01-0.17 g·L~(-1). The average extraction rate of NF standard decoction was(14.4±2.6)%, the average transfer rate of quercetin-3-O-glucuronic acid was(70.7±18.6)%, and the average transfer rate of nuciferine was(9.6±5.4)%. Compared with Nuciferine, quercetin-3-O-glucuronic acid had a high content and stable transfer rate in standard decoction, and was recommended to be the quality control marker for NF and its standard decoction. This paper establishes a quality evaluation method for NF standard decoction, and can provide reference for the quality control of all preparations derived from NF and its decoction.

[Reproductive toxicity of triptolide and its mechanism in male rats].

The arrenotokous toxicity of triptolide was evaluated, and the rate of sperm abnormality, the changes of the lipid peroxide, the enzyme activity and the hormone in male rats were observed. With the negative and positive control group, the healthy rats were respectively given by gavage triptolide suspension at the dose of 0.025, 0.05, 0.1 mg x kg(-1) for 30 days. Then the rats were killed for the measurement of the indicators in testis and serum, as well as the study on the sperm abnormality. The results showed that the positive control group had significant difference, compared with the negative control group. The content of SOD, LDH, G-6-PD, Na+ -K+ -ATPase, Ca+ -Mg+ -ATPase decreased significantly in 0.05 mg x kg(-1) group, and reduced more obviously with exposure to the dose of 0.1 mg x kg(-1). The levels of GSH-Px and beta-G showed a significant decrease in the testis of rats only at the dose of 0.1 mg x kg(-1). Nevertheless, the MDA levels, the FSH levels and the LH levels showed no significant difference. The deformity rate of sperm increased significantly in 0.05 mg x kg(-1) group and 0.1 mg x kg(-1) group. The results indicated the triptolide had the effect of the lipid peroxidation to damage Spermatogenic cells, Sertolis cells and Leydig cells. At the same time, the triptolide interfered not only with the energy supply process of aerobic and anaerobic glycolysis,but also with the energy utilization in testis by affecting the activities of testis marker enzymes, and produced a damage chain of the male reproductive system