Due to the nontoxicity and efficient anti-cancer activity, more and more attention has been paid to N-glycoside compounds. Laser photolysis of N-(α-D-glucopyranoside) salicyloyl hydrazine (NGSH) has been performed for the first time. The research results show that NGSH has high photosensitivity and is vulnerable to be photo-ionized via a monophotonic process with a quantum yield of 0.02, generating NGSH+· and hydrated electrons. Under the aerobic condition of cells, the hydrated electrons are very easy to combine with oxygen to generate 1O2 and O2-, both of which are powerful oxidants that can kill the cancer cells. In addition, NGSH+· can be changed into neutral radicals by deprotonation with a pKa value of 4.02 and its decay constant was determined to be 2.55×109dm3·mol-1·s-1. NGSH also can be oxidized by SO4-. with a rate constant of 1.76×109 dm3·mol-1.s-1, which further confirms the results of photoionization. All of these results suggest that this new N-glycoside compound might be useful for cancer treatment.
To evaluate the antitumor activity and pharmacokinetics of podophyllotoxin(PPT) incorporated into solid lipid nanoparticles(SLN),Kunming mice inoculated with flesh tumor were used as animal model.The mice received a single daily intraperitoneal injection of PPT in 20% ethanol(5 mg/kg) and PPT-SLN(5 mg/kg in PPT) for 3 weeks.Gross tumor volumes,body weight and clinical observations were recorded daily.The mice were sacrificed for 24 h after the last administration,and the tumor inhibition rate was calculated with the tumor weight.For the pharmacokinetics research,the mice were treated with intraperitoneal injection of PPT(10 mg/kg) and PPT-SLN(10 mg/kg in PPT).Blood samples were collected at different time to determine the PPT concentration in plasma by HPLC.Blood drug level-time curve was made and pharmacokinetic parameters were calculated.As a result of drug administration,the tumor volume and weight of the mice injected with PPT-SLN were significantly restrained compared with mice treated with PPT or negative control.The tumor inhibition rate of 58.13% showed a significant antitumor activity of PPT-SLN.At the same time,the increased weight gain of the mice injected with PPT-SLN suggested a reduced toxicity of PPT in SLN.Pharmacokinetics study displayed a higher blood concentration,a prolonged circulation time,and an increased bioavailability of PPT-SLN compared with those of PPT.Our results demonstrated that PPT-SLN could optimize pharmacokinetics,enhance antitumor activity and attenuate toxicity,so it has a promising prospect for the application in anti-tumor treatment.
A series of nanostructured iron compounds including cubic Fe3O4 and orthorhombic FeOOH were synthesized via a facile low temperature (in the range of 60-100℃) solution method. In the whole process, the interaction between FeCl2·4H2O and methenamine (C6H12N4) was carried out through a reflux device under different reaction conditions such as temperature, solvent, and duration. The samples were detected by XRD, TEM, SAED, physical property measurement system, and Mssbauer spectroscopy, separately. The experiments showed that magnetic mixture nanoparticles had flake and rod morphologies, and cubic Fe3O4 took on grain nanostructure. Magnetism measurements indicated that the saturated magnetization of the as-obtained magnetic mixture was lower than that of the cubic magnetite. Mssbauer spectroscopy testified the sample consisting of cubic magnetite rather than γ-Fe2O3. In addition, a possible growth mechanism of cubic magnetic nanoparticles under different conditions was discussed.
LIU Yi1,2, CHEN Yun1, ZENG YuPing2 & WANG ShiLong3 1 Department of Chemistry and Chemical Engineering, Zaozhuang University, Zaozhuang 277160, China
To study the molecular mechanism of high mutation frequency induced by high-energy-pulse-electron (HEPE) beam radiation, the effects of HEPE radiation on yeast cells, plasma membrane, plasmid DNA, and protein activity were investigated by means of cell counting, gel electrophoresis, AO/EB double fluorescent staining, etc. The results showed that the viability of yeast cells declined statistically with increase of absorbed doses. The half lethal dose (LD50) was 134 Gy. HEPE beam radiation had little influence on the function of plasma membrane and protein, while it could induce much DNA damage of single strand breaks (SSB) and double strand breaks (DSB) that were required for gene mutation. The G-value for DSB formation of HEPE beam radiation in aqueous solution was 5.7 times higher than that caused by 60Co gamma rays. HEPE can be a new effective method for induced mutation breeding and deserves further research in the future.
