[Preliminary study on synthesis of novel amphiphilic molecules and their application as drug vectors].

OBJECTIVE: To synthesize three amphiphilic molecules (TEG-R1, TEG-R2, TEG-R3), with branched oligo polyethylene glycol as hydrophilic fractions and aliphatic chains (containing six, eight and twelve carbon atoms respectively) as hydrophobic fractions, and study them as insoluble drug vectors. METHOD: Three compounds were successfully through acylation, substitution reaction, reduction reaction and esterification. Their structures were verified by NMR analysis; and the critical micelle concentrations (CMC) of TEG-R1, TEG-R2, TEG-R3 were determined by pyrene fluorescence probe spectrometry. Transmission electronic microscopy (TEM) photos displayed the state of the aqueous solution. The self-assembly solution evaporation method was adopted to prepare drug loading podophyllotoxin micelles, and characterize their grain size, in order to detect the hemolysis of the three amphiphilic molecules. RESULT: Nuclear magnetism showed the successful synthesis of three amphiphilic molecules, with critical micelle concentrations of TEG-R1, TEG-R2, TEG-R3 of 50, 50, 10 mg x L(1), respectively. Transmission electronic microscopy (TEM) photos displayed a spherical-like state, with diameter of 20-50 nm. All of the three amphiphilic molecules could be prepared into drug-loading micelles, with the range of grain sizes between 100-200 nm. Hemdytic experiment showed that, among the amphiphilic molecules of the graft six-carbon aliphatic chain, TEG-R1 could not cause hemolysis. CONCLUSION: All of the three amphiphilic molecules are micellized in water solution, and can be used as insoluble drug vectors. Among them, TEG-R1 could not cause hemolysis, and is expected to become a new-type drug vector.

Effects of mulching duration on PAEs accumulation in soil and tobacco leaves in Zunyi, China.

We examined the effects of the duration of plastic film mulching on the accumulation of phthalate (PAEs) in soils and tobacco to determine the soil pollution distribution characteristics of PAEs under continuous mulch use and the enrichment status in tobacco leaves. Samples of both soils and tobacco leaves were collected from Lianqian Village and Shawan Village of Zunyi. Gas chromatography-mass spectrometry (GC-MS) was used to determine the contents of six preferentially controlled PAEs in samples. The results showed that the six ΣPAEs in all soil and tobacco samples were (2.66 ±0.60) and (3.58±0.64) mg·kg-1, of which the content of DEHP was the highest, followed by DBP, with the sum of those two accounting for 92.7% and 88.9% of ∑PAEs in the soil and tobacco, respectively. The detection rates of DEHP, DBP, DEP, and BBP were 100.0%. The detection rate of DMP was slightly lower, and that of DnOP was the lowest. The content of PAEs in soils and tobacco leaves significantly increased with the increases of mulching years. In the 1-8 years of film mulching, the increases of PAEs were more obvious and tended to be gentle in the later stage. The content of PAEs in soil and tobacco leaves had significant positive correlation with the years of film mulching, indicating that the increase of film mulching years could significantly promote the accumulation of PAEs. There was no significant correlation between the ∑PAEs accumulation between tobacco leaves and soil.