异叶南星的化学成分研究

目的 :对异叶南星的化学成分进行研究。方法 :采用硅胶柱色谱、薄层色谱对异叶南星的化学成分进行分离 ,并用理化常数和光谱鉴定其结构。结果 :从异叶南星中分离出 4个化合物 ,分别为十八酸单甘酯 (glycerolmonostearicacid ,Ⅰ ) ,β 谷甾醇 (β sitosterol,Ⅱ )、葫萝卜甙 (daucosterol,Ⅲ )、琥珀酸 (succinicacid ,Ⅳ ) ,结论 :化合物Ⅰ。

Glycerin Monostearate Aggravates Male Reproductive Toxicity Caused by Di(2-ethylhexyl)Phthalate in Rats

Human beings are increasingly exposed to phthalates,which are a group of chemicals used to make plastics more flexible and harder to break,and simultaneously ingesting abundant food emulsifiers via daily diet.The purpose of this study was to investigate the effect of the food emulsifier glycerin monostearate(GMS)on male reproductive toxicity caused by di(2-ethylhexyl)phthalate(DEHP,one of the phthalates)and explore the underlying mechanism.Thirty male Sprague-Dawley rats were randomly divided into control group,DEHP group and DEHP+GMS group.Rats in the DEHP group and DEHP+GMS group were orally administered with 200 mg/kg/d DEHP with or without 20 mg/kg/d GMS.After 30 days of continuous intervention,it was found that the serum testosterone level was significantly lowered in DEHP group and DEHP+GMS group than that in control group(P<0.01).The serum testosterone level and the relative testis weight were significantly decreased in the DEHP+GMS group as compared with those in the DEHP group and control group(P<0.05).More spermatids were observed to be shed off in DEHP+GMS group than in DEHP group.The expression levels of cell cycle checkpoint kinase 1(Chkl),cell division cycle gene 2(Cdc2),and cyclin-dependent kinase 2(CDK2)were down-regulated in DEHP group,and this tendency was more significant in DEHP+GMS group(P<0.05 or P<0.01).There was no significant difference in the P-glycoprotein(P-gp)expression between DEHP group and control group.However,P-gp was markedly down-regulated in DEHP+GMS group(P<O.Ol).The results indicated that the food emulsifier GMS aggravated the toxicity of DEHP on male reproduction by inhibiting the cell cycle of testicular cells and the expression of P-gp in testis tissues.

Effect of silicone oil on the microstructure, gelation and rheological properties of sorbitan monostearate–sesame oil oleogels

Oleogels contain oil or a non-polar liquid which is gelled with an agent called an organogelator. The aim of this study was to evaluate the effects of the addition of silicone oil(cyclopentasiloxane) to the gelation process and to the properties of sorbitan monostearate(SMS)–sesame oil oleogel and compared with that of SMS–sesame oil oleogel and SMS–cyclopentasiloxane oleogel. Three different oil phases; sesame oil phase, cyclopentasiloxane phase and a mixture of cyclopentasiloxane and sesame oil, were used to prepare oleogels with SMS gelator. The critical gelling concentrations(CGC) for oleogels were determined using different concentration of SMS in a range of 5%–22%(w/w). The characterization of the developed oleogels was done using Fourier transform infrared spectroscopy(FTIR), polarized light microscope, rheometer, X-ray diffraction(XRD) and differential scanning calorimetry(DSC). The addition of cyclopentasiloxane reduced the CGC of SMS–sesame oil oleogel from 20% to 10%(w/w). In microscopic characterization, the oleogels with a mixture of oil phases showed the longer and thicker three-dimensional gel network than that of oleogels with sesame oil and cyclopentasiloxane. FTIR studies demonstrated that this network formation was mainly due to hydrogen bonding. Rheological measurements revealed that the combination of cyclopentasiloxane and sesame oil produced strong gel with higher complex modulus values and longer linear viscoelastic region than oleogels prepared with sesame oil and cyclopentasiloxane. In addition, oleogels with the combination of the two oils had higher enthalpy( H m) and entropy( S m) thus could increase thermodynamic stability of the oleogels. Therefore, the addition of cyclopentasiloxane can improve the physical, ther-mal properties and stability of SMS–sesame oil oleogel, provide greater sensory profile and better product aesthetics. The developed oleogel can be a novel carrier for topical drug delivery.

Hot-melt sub-and outercoating combined with enteric aqueous coating to improve the stability of aspirin tablets

Aspirin is apt to hydrolyze. In order to improve its stability, a new method has been developed involving the application of hot-melt sub-and outercoating combined with enteric aqueous coating. The main aim was to investigate the influence of these factors on the stability of ASA and understand how they work. Satisfactory storage stability were obtained when the aspirin tablet core coated with Eudragit L30D55 film was combined with glycerin monostearate(GMS) as an outercoat. Hygroscopicity testing indicated that the moisture penetrating into the tablet may result in a significant change in the physical properties of the coating film observed by scanning electron microscopy. Investigation of the compatibility between the drug and film excipients shows that the talc and methacrylic acid had a significant catalytic effect on ASA. A hypothesis was proposed that the hydrolysis of ASA enteric coated tablets(ASA-ECT) was mostly concentrated in the internal film and the interfaces between the film and tablet core. In conclusion, hot-melt coating technology is an alternative to subcoating or outercoating. Also, GMS sub-coating was a better choice for forming a stable barrier between the tablet core and the polymer coating layer, and increases the structure and chemical stability.

A Comparative Study of the Hydroxyl and Saponification Values of Polysorbate 60 in International Food Additive Specifications

We investigated the hydroxyl and saponification values of 27 samples of Polysorbate 60 products that were commercially available worldwide. We observed that the values of most of the studied samples were not within the range established at the Joint FAO/WHO Expert Committee on Food Additives (JECFA), while they did agree with the specifications described in the USA, the EU and Japan. We believe that purities of the new commercial Polysorbate 60 samples are higher than those of the older products which were available when the JECFA specifications were discussed (around 1973). The present study suggests that the hydroxyl and saponification values of the current JECFA specifications for Polysorbate 60 should be re-evaluated.

Food emulsifier glycerin monostearate aggravates phthalates'testicular toxicity by disrupting tight junctions'barrier function in rats

Objectives:This study aimed to investigate the effect of the widely used food emulsifier glycerin monostearate(GM)on testicular toxicity caused by the mixture of three commonly used phthalate esters(MPEs)in rats,and further to explore the underlying mechanism.Materials and Methods:Thirty male Sprague-Dawley rats were randomly divided into three groups.Rats were orally treated with 160 mg/kg/d MPEs in the MPEs group;coinstantaneously treated with 160 mg/kg/d MPEs and 200 mg/kg/d GM in the MPEs+GM group;and treated with the excipient in the control group.The intervention lasted for 5 weeks.Testis weight,epididymis weight,testicular histopathology,and serum testosterone were detected for testicular toxicity evaluation.The testicular ultrastructure,the tight junction proteins zonula occluden(ZO)-1,and claudin were measured for the mechanism exploration.Results:The body weight,epididymis,serum testosterone level,and anogenital distance in the MPEs+GM group were significantly decreased compared with control group(P<0.05);Testicular histopathological observation showed that shed spermatids were observed in the MPEs+GM group.Ultrastructural observation of testicular cells showed that the cristae number was decreased in some mitochondria in the MPEs group,whereas the cristae were fused and disappeared in most mitochondria in the MPEs+GM group.The tight junctions were broken in the MPEs+GM group;meanwhile,the expression of ZO-1 and claudin were altered in the MPEs+GM group(P<0.01).Conclusions:The results from this study indicated that GM aggravated MPEs'testicular toxicity,which might relate to the injured mitochondria and damaged tight junctions in testicular tissue.

All-Atom Molecular Dynamics Simulation of Structure and Diffusion of Hydrophilic Antistatic Agents in Polypropylene

Glycerol monostearate(GMS)is an additive widely used in plastic industry for its good ability to improve the wettability and antistatic property of polymer surfaces.Based on GMS,we propose five additives of different polar-ity by attuning the number of oxyethyl groups.All-atom molecular dynamics simulations of these additives in poly-propylene(PP)matrix are carried out at temperatures of 300 K,350 K and 400 K.Detailed molecular conforma-tions are obtained and analyzed.Due to the gauche effect of the dihedral angles,the polar parts of these additives form helix structures.The diffusion coefficient of the additives depends on their molecular conformations and de-creases monotonously with increasing polarity.