本文選題：殼聚糖　切入點：雙胍鹽　出處：《華中農(nóng)業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：殼聚糖以其良好的生物相容性和生物活性在微生物抑菌方面?zhèn)涫荜P(guān)注,然而抑菌性能不佳限制了其開發(fā)應(yīng)用范圍。文獻報道殼聚糖所帶正電荷越多其抑菌性能越強,本文以增加殼聚糖所帶正電荷為目標,在殼聚糖上引入雙胍和季銨兩種基團,并合理簡化合成步驟,得到帶有不同正電荷的N-雙胍殼聚糖和N-雙胍-O-季銨化殼聚糖衍生物,研究其對常見的致病菌的抑菌性能和規(guī)律,并將其運用于奶牛子宮內(nèi)膜炎的體外評價。1.研究溶解條件、反應(yīng)溫度、時間、溶液p H值、投料比對產(chǎn)率的影響優(yōu)化后最佳條件為20℃酸性條件下溶解,70℃下p H值為5時加入2倍摩爾比的雙氰胺進行胍基化反應(yīng)4h,80℃下p H值為9時加入1倍摩爾比的CTA進行季銨化反應(yīng)12h。溫度和溶液的p H值對反應(yīng)影響較大,溫度過高殼聚糖易分解,非適宜p H下,副產(chǎn)物較多、產(chǎn)率低。2.研究分子量、濃度、高溫等因素對殼聚糖衍生物抑菌性能的影響實驗研究表明,殼聚糖分子量越小,其抑菌性能越強;增加殼聚糖的濃度,其抑菌性能明顯增強,本文抑菌試驗中適宜樣品濃度為0.1mg/ml;CS、N-雙胍化CS、N-雙胍-O-季銨化CS對大腸桿菌K88、金黃色葡萄球菌、沙門氏菌均具有良好的抑菌效果且依次增強,提高樣品濃度能夠明顯增強抑菌性能;高溫滅菌并沒有降低殼聚糖及其衍生物的抑菌性能。結(jié)果證明,增加殼聚糖所帶正電荷能夠有效的增強其抑菌性能;本樣品適合使用高溫滅菌法;金黃色葡萄球菌對殼聚糖衍生物敏感,提高濃度能夠有效的提高其抑菌效果。3.研究殼聚糖衍生物對奶牛子宮內(nèi)蠟樣芽孢桿菌和混菌的抑菌性能實驗研究表明,以某奶牛場中患有子宮內(nèi)膜炎的牛子宮內(nèi)分離出來的臨床單菌-蠟樣芽孢桿菌和直接提取出來的混合致病菌為菌種,CS、N-雙胍化CS、N-雙胍-O-季銨化CS對其抑菌效果依次增強;當菌的種類增加時殼聚糖衍生物的整體抑菌率會下降。
[Abstract]:Chitosan has attracted much attention because of its good biocompatibility and bioactivity. However, its poor bacteriostatic performance limits its development and application. It is reported in the literature that the more the positive charge of chitosan is, the stronger its bacteriostatic activity is. In order to increase the positive charge of chitosan, biguanidine and quaternary ammonium groups were introduced into chitosan, and the synthetic steps were reasonably simplified to obtain N-biguanidine chitosan and N-biguane-O-quaternary ammonium chitosan derivatives with different positive charges. To study the bacteriostasis and its regularity of common pathogenic bacteria, and to apply it to the evaluation of cow endometritis in vitro. 1. To study the dissolution conditions, reaction temperature, reaction time, pH value of solution. Effect of feed ratio on yield the optimum conditions are as follows: dissolved at 70 鈩，

本文編號：1592100