Immune response,stress resistance and bacterial challenge in juvenile rainbow trouts Oncorhynchus mykiss fed diets containing chitosan-oligosaccharides

Effects of dietary supplementation of chitosan-oligosaccharides(COS)on the growth performance,immune response,stress resistance,and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied.Four experimental diets containing 0,20,40,or 60 mg/kg COS(COS0,COS20,COS40,and COS60,respectively)were fed to juvenile rainbow trout(initial weight=5.2±0.3 g)for 8 weeks.By the end of the feeding trial,representative groups of fish from each dietary treatment were challenged with stressor(30 sec air exposure)and pathogen exposure(intraperitoneal injection with Aeromonas hydrophila).Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout.However,fish fed the COS40 diet demonstrated improved phagocytic activities,respiratory burst activities and decreased serum cortisol level.Additionally,survival following A.hydrophila challenge was significant higher among fish fed the COS-supplemented feeds,although there was no difference based on the level of supplementation.The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds.

Chitosan Oligosaccharide-Ca Complex Accelerates the Depuration of Cadmium from Chlamys ferrari

This study investigated the effect of a chitosan oligosaccharide-Ca complex (COS-Ca) on the depuration of cadmium (Cd) from Chlamys ferrari. After exposure to 0.5 mg L-1 CdCl2 for 3 or 7 d, the scallops were treated by COS-Ca prior to determina-tion of Cd, calcium (Ca) and zinc (Zn) contents, Cd distribution in organs, malondialdehyde (MDA) content and antioxidant variables. Results showed that COS-Ca reduced Cd content in the viscera of the scallops, with highest Cd depuration rate (47%) observed on day 3. The COS-Ca concentration substantially affected Cd depuration, and the exposure to 8.75 mg L-1 COS-Ca led to significantly higher Cd depuration rate compared with those of lower COS-Ca concentrations (1.75, 3.5, 5.25, and 7.00 mg L-1). Distribution analysis of Cd in scallop organs indicated that COS-Ca significantly reduced Cd content in the kidney throughout the 5-d experiment, as well as in the gill during the early stage of Cd depuration. In addition, COS-Ca treatment decreased glutathione peroxidase (GSH-Px) activity and MDA content while increasing superoxide dismutase (SOD) and catalase (CAT) activities on different days. Our work suggested COS-Ca complex treatment as an effective method for acceleration of Cd depuration from Cd-contaminated bivalves.

Effects of Five Chitosan Oligosaccharides on Nuclear Factor-kappa B Signaling Pathway

The effects of five chito-oligomers, from dimer to hexamer （chitobiose, chitotriose, chitotetraose, chitopentaose, chitohexaose） separated from chitosan oligosaccharides, on nuclear factor -kappaB （NF-rd3） signaling pathway were investigated by using luciferase assay and laser scanning microscopy. The expression of NF-rd3 downstream genes （cyclin DI, TNFa and IL-6） were tested by real time PCR. We found that all five chitosan oligosaccharides increased NF-KB-dependent luciferase gene expression and NF-KB downstream genes transcription, and the most significant were chitotetraose and chitohexaose. In addition, laser scanning microscopy experiments showed that chitotetraose and chitohexaose also activated the p65 subunite of NF-kB translocating from cytoplasm to nucleus, which suggested that they were the most potent activators of NF-kB signaling pathway.

Specific Targeting MRI of Chitosan Oligosaccharide Modified Fe_(3)O_(4) Nanoprobe on Macrophage and the Inhibition of Macrophage Foam­ing Induced by ox-LDL

Atherosclerosis(AS)is a primary cause of morbidity and mortality all over the world.Molecular imaging techniques can enable early localization and diagnosis of atherosclerosis plaques.Recent newly developed chitooligosaccharides(CSO)is considered to be capable of target mannose receptors on the surface of macrophages and to inhibit foam cell formation.Here we present a targeting magnetic resonance imaging(MRI)nanoprobe,which was successfully constructed with polyacrylic acid(PAA)modified nanometer iron oxide(Fe_(3)O_(4))as the core,and coating with CSO molecules,possessing the abilities of targeted MRI and specifically inhibition of the formation of foamy macrophages in the atherosclerotic process.The experimental results showed that the distributions of PAA-Fe_(3)O_(4) and CSO-PAA-Fe_(3)O_(4) were uniform and the corresponding sizes were about 5.93 nm and 8.15 nm,respectively.The Fourier transform infrared spectra(FTIR)testified the CSO was coupled with PAA-Fe_(3)O_(4) successfully.After coupled with CSO,the r1 of PAA-Fe_(3)O_(4) was increased from 5.317 mM s-1 to 6.147 mM s-1,indicating their potential as MRI contrast agent.Oil Red O staining and total cholesterols(TC)determination showed that CSO-PAA-Fe_(3)O_(4) could significantly inhibit the foaming process of RAW264.7 cells induced by oxidatively modified low density lipoprotein(ox-LDL).In vitro cellular MRI displayed that,compared with PAA-Fe_(3)O_(4),CSO-PAA-Fe_(3)O_(4) could lower the T1 relaxation time of RAW264.7 cells better.In summary,construction of CSO-PAA-Fe_(3)O_(4) nanoprobe in this study could realize the targeted MRI of macrophages and inhibition of ox-LDL induced macrophage foaming process.This will provide a new avenue in the diagnosis and treatment of AS.

Synthesis of Water-Soluble Chitosan From Squid Pens Waste for Capsule Shell Materials

Water-Soluble Chitosan(WSC)has been sucessfuly synthesized from squid pens waste.The synthesis of chitosan from chitin was carried out by optimization of deacetylation temperature and time.Chitin was obtained from squid pens waste by demineralization and deproteinization process.HCl 7%was used for demineralization and NaOH 10%at 60℃ was applied for deproteinization process.Deacetylation reaction was carried out at varied temperatures i.e.,60℃,70℃,80℃,90℃ and 100℃ in NaOH 50%solution for 10 hours.Deacetylation reaction time were varied for 2 hours,4 hours,6 hours,8 hours,and 10 hours.The crude chitosan obtained then reacted with H2O230%to depolymerize.The synthesis product obtained then characterized by FTIR.The result of squid chitin yield was 33.9%.The optimum temperature and time of chitosan deacetylation process were 90℃ for 8 hours as indicated by the value of deacetylation degree(DD)that equal to 83.94%at optimum temperature and 82.22%at optimum reaction time.The percentage of WSC yield at optimum temperature(90℃)and optimum time(8 hours)were 27.59%and 23.16%,respectively.WSC solubility test was done in water and HCl 0,1N.The solubility of 2.8325 mg/mL and 0.8125 mg/mL were obtained in acid medium and water medium,respectively.

壳三糖和壳五糖对睡眠剥夺小鼠学习记忆障碍的影响

各种原因引起的睡眠时间减少已成为生活常态,睡眠剥夺会降低机体的学习记忆能力,影响生活质量。该研究对C57BL/6J小鼠进行21 d睡眠剥夺,同时每天对小鼠灌胃壳三糖(chitotriose,COS3)和壳五糖(chitopentaose,COS5),通过体重、新物体识别实验、病理学染色、氧化应激和凋亡相关蛋白表达评估COS3和COS5的保护作用。结果显示,COS3和COS5干预能够缓解小鼠体重下降和海马神经细胞坏死变形,显著提高海马组织中超氧化物歧化酶水平和总抗氧化能力,显著降低海马丙二醛含量。COS3和COS5干预能够显著提升海马p-PI3K(phospho-phosphotylinosital 3 kinase)和p-Akt(phospho-protein kinase B)蛋白的相对表达量,激活PI3K/Akt信号通路,缓解神经细胞凋亡。研究表明,COS3和COS5能够明显改善睡眠剥夺引起的学习记忆能力下降,其机制可能与COS3和COS5能够缓解海马组织氧化应激和神经细胞凋亡有关,其中COS3的效果优于COS5。

壳寡糖浸种对低温下江西铅山红芽芋脱毒试管芋萌发及生理代谢的影响

江西铅山红芽芋脱毒试管芋一般在1月至2月上旬晴天播种,“倒春寒”等低温胁迫会导致早播的江西铅山红芽芋脱毒试管芋生长缓慢,出苗周期变长,严重时会造成烂种死亡,出苗率降低,影响其产量。为提高播种期江西铅山红芽芋脱毒试管芋抗寒性,该研究利用植物组织培养和植物生理学的方法测定了壳寡糖浸种后低温下江西铅山红芽芋脱毒试管芋的萌发及其相关生理指标。结果表明:200~250 mg/L壳寡糖浸种可显著促进低温下江西铅山红芽芋脱毒试管芋的萌发。与低温对照相比,当浸种浓度为200 mg/L时,在内源激素方面,有利于低温下江西铅山红芽芋脱毒试管芋萌发过程中赤霉素、玉米素核苷、多胺和茉莉酸的积累,而不利于生长素和脱落酸的积累;在抗氧化方面,提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,降低了丙二醛和过氧化氢的含量;在渗透调节方面,有利于可溶性糖、可溶性蛋白、脯氨酸的积累;在代谢关键酶方面,可提高脂肪酶、蛋白酶和α-淀粉酶活性以及三磷酸腺苷含量。因此,200 mg/L壳寡糖可以调控低温下江西铅山红芽芋脱毒试管芋内源植物激素和渗透调节物质含量、抗氧化酶和代谢关键酶活性,促进其在低温下的萌发。

壳寡糖的生物活性及其在食品添加剂方面的应用进展

壳寡糖(chitosan oligosaccharide,COS)是由壳聚糖通过物理、化学或酶水解等方法脱乙酰解聚得到的多糖,是自然界中唯一具有正电荷的阳离子碱性氨基寡糖,其主要来源于虾壳、贝类等甲壳类水生物。根据分子量、聚合度、脱乙酰度、电荷分布、各单元排列方式不同,COS能表现出不同的物理化学特性,然而,COS的生物活性主要来自于各单元的羟基和氨基。由于COS具有诸多特殊活性(如抗菌、抗氧化、抗炎等),目前已经被广泛应用于医学、化妆和农业等多个领域,但在食品领域的应用相对较少,且对COS的生物活性及在食品添加剂方面的应用缺乏系统总结报道。本文通过对COS的结构、性质以及其生物活性的阐述,总结了COS在食品添加剂中如保鲜剂、功能因子添加剂、风味改善剂中的应用与发展,对COS在食品加工领域未来的发展进行展望,为食品加工方面的应用提供新思路。

不同外源寡糖对设施黄瓜生理特性及产量和品质影响差异

选择壳寡糖(GT)和复合寡糖(KP)为制剂处理,以大棚常规对照(CG)和清水对照(CK)为对比,分析黄瓜叶片叶绿素相对含量(SPAD)、叶绿素荧光参数和超微结构,根系表观形态和根系活力(RV),以及抗氧化酶和内源激素的变化,比较不同类型寡糖制剂对设施黄瓜生长及产量的调控作用。结果表明:与其他处理相比,KP处理能有效促进黄瓜叶片和根系生长,其SPAD、最大光化学量子产量(Fv/Fm)、光化学淬灭系数(qP)、非光化学淬灭系数(NPQ)和RV均显著增加4.15%~15.63%、6.49%~20.03%、33.33%~152.63%、10.37%~71.62%和8.51%~171.43%;超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性显著提升6.75%~91.49%、3.85%~97.62%和3.00%~28.15%;此外,促使黄瓜生育后期叶片生长素(IAA)含量显著提高5.43%以上,脱落酸(ABA)含量显著降低4.35%~18.63%;黄瓜产量和可溶性糖含量显著增加13.72%和11.52%以上。比较而言,GT处理对黄瓜根冠生长,内源激素和抗氧化酶活性的影响表现出不稳定性,仅坐果期叶片光合生理特性(SPAD、叶绿素荧光参数和叶片超微结构)和RV有所改善。相较于GT处理,KP处理在促进黄瓜根冠生长,调控抗氧化酶活性和内源激素平衡方面具有明显优势。结合相关性分析发现,黄瓜产量与NPQ、RV、SOD和POD活性呈极显著正相关(P<0.01),与Fv/Fm显著正相关(P<0.05);且SOD和POD活性均与ABA含量显著负相关(P<0.05)。综上,外源复合寡糖主要通过促进黄瓜根冠协调生长,维持生育后期高光合效率、根系活力和叶片功能结构稳定,调节抗氧化酶活性,促进生长激素和抑制生长激素间的平衡,保障生育后期细胞膜功能稳定,延缓叶片自然衰老,实现黄瓜的提质增产。

氮肥运筹与化学调控对双季稻产量及其抗倒伏特性的影响

以早稻品种陆两优996、株两优819及晚稻品种H优518、盛泰优018为材料,于2020年开展大田试验,设计3种氮肥运筹方式N1、N2、N3(分蘖肥、穗肥、粒肥用量比分别为7∶2∶1、6∶3∶1、5∶4∶1)与2种化学调控剂多效唑(C1)、壳寡糖(C2)双因素试验,研究氮肥运筹方式和化学调控对水稻产量及抗倒伏能力的影响。结果表明:氮肥运筹和化学调控对水稻产量影响显著,早、晚稻各品种产量均以N2C2处理的最高,主要通过提高植株有效穗数而增产;与N1相比,N2和N3降低了茎秆高度、节间长度和重心高度,增加了茎粗、茎壁厚度和节间充实度,茎秆抗倒伏能力增强,且N2优于N3处理;与对照处理(C3,喷施清水)相比,C1和C2均降低了水稻茎秆高度、重心高度和节间长度,增加了茎粗、茎壁厚度和节间充实度,从而提高了水稻抗倒伏能力;从互作效应来看,N2C1、N2C2和N3C1处理的茎粗和茎壁厚度较大,倒3与倒4节节间长度较短,节间充实度和抗折力较高,倒伏指数较低。综合考虑各品种倒伏指数和产量性状,N2C2处理,即分蘖肥、穗肥、粒肥施用比例为6∶3∶1条件下,于拔节初期喷施壳寡糖,可在提高双季稻抗倒伏能力的同时获得最高产量。

Fibroblast exosomal TFAP2C induced by chitosan oligosaccharides promotes peripheral axon regeneration via the miR-132-5p/CAMKK1 axis

Chitosan and its degradation product,oligosaccharides,have been shown to facilitate peripheral nerve regeneration.However,the underlying mechanisms are not well understood.In this study,we analyzed the protein expression profiles in sciatic nerves after injury using proteomics.A group of proteins related to exosome packaging and transport is up-regulated by chitosan oligosaccharides(COS),implying that exosomes are involved in COS-induced peripheral nerve regeneration.In fact,exosomes derived from fibroblasts(f-EXOs)treated with COS significantly promoted axon extension and regeneration.Exosomal protein identification and functional studies,revealed that TFAP2C is a key factor in neurite outgrowth induced by COS-f-EXOs.Furthermore,we showed that TFAP2C targets the pri-miRNA-132 gene and represses miR-132-5p expression in dorsal root ganglion neurons.Camkk1 is a downstream substrate of miR-132-5p that positively affects axon extension.In rats,miR-132-5p antagomir stimulates CAMKK1 expression and improves axon regeneration and functional recovery in sciatic nerves after injury.Our data reveal the mechanism for COS in axon regeneration,that is COS induce fibroblasts to produce TFAP2C-enriched EXOs,which are then transferred into axons to promote axon regeneration via miR-132-5p/CAMKK1.Moreover,these results show a new facet of fibroblasts in axon regeneration in peripheral nerves.

饲料中间隔添加壳寡糖对仿刺参生长、非特异性免疫和消化的影响

壳寡糖是良好的免疫增强剂,但在水生动物中的应用还十分有限。本研究通过间隔投喂的方式研究壳寡糖对仿刺参生长性能、非特异性免疫能力、消化能力、组织学和抗病力的影响。实验挑选体重(18.51±0.28)g的仿刺参,对照组饲喂基础饲料,实验组以3天1次的饲喂频率饲喂含0.5%壳寡糖的饲料,其余时间饲喂基础饲料,连续投喂8周后,检测该饲喂方式下仿刺参生长性能、非特异性免疫能力、肠道消化酶、肠道和呼吸树组织学、肠道免疫基因表达情况以及对灿烂弧菌的抗病力。结果显示,3天1次的壳寡糖饲喂频率极显著提高了仿刺参的脏壁比和肠壁比;在免疫指标方面,显著提高了仿刺参体腔细胞的吞噬活性和呼吸爆发能力,极显著提高了肠道的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、溶菌酶(LZM)和总一氧化氮合酶(T-NOS)活性,其中肠道AKP和LZM活性分别提高了70.06%和156%,肠道Aj-lyz基因表达量极显著提高了22.04%;抗氧化指标结果显示,实验组极显著提高了仿刺参体腔细胞过氧化氢酶(CAT)活性,而体腔细胞和肠道的丙二醛(MDA)含量无显著差异。组织学结果显示,该饲喂频率极显著提高了仿刺参前肠肌肉层厚度和浆膜层厚度,中肠和后肠的皱襞高度和宽度。灿烂弧菌攻毒结果表明,实验组仿刺参的相对保护率达到66.67%。研究表明,3天1次的饲喂频率能够一定程度上提高仿刺参的生长性能,非特异性免疫酶、消化酶活性,并明显改善肠道结构。研究结果可为壳寡糖对仿刺参作用机制的研究及投喂频率的确定提供数据支撑和理论依据。

壳寡糖上调SRBI核心岩藻糖基化修饰水平减弱小鼠动脉粥样硬化斑块形成

目的 从蛋白糖基化修饰角度探讨壳寡糖(COS)减弱动脉粥样硬化(AS)斑块形成的机制。方法 将40只ApoE-/-小鼠随机分为对照组和COS组。对照组饲给予高脂饲料12周,COS组给予高脂饲料+COS(每天灌胃,500 mg/kg)12周。全自动生化分析仪检测两组小鼠的血脂水平并对主动脉斑块切片进行HE和油红O染色。凝集素芯片、液相色谱-串联质谱、酶联免疫吸附试验检测血清中糖蛋白变化。胆固醇酯流出实验和游离胆固醇酯测定实验评价清道夫受体B类成员1(SRBI)糖基化修饰位点改变对巨噬细胞胆固醇流出量的影响。结果 COS显著降低小鼠TC和LDL-C水平(P<0.05),但对TG、HDL-C、ApoA1和ApoB100无影响。与对照组相比,COS组主动脉内膜厚度和斑块大小明显变薄、变小(P<0.05)。两组小鼠血清中变化最明显的小扁豆凝集素(LCA)结合蛋白分子量为80~90 ku,清道夫受体B类成员1为其中之一。COS促进了细胞内胆固醇的流出,抑制了游离胆固醇酯的积累(P<0.05)。SRBI敲低或N108糖基化位点突变可抑制COS引起的胆固醇流出,增加细胞内游离胆固醇的积累(P<0.05)。结论 COS通过增加SRBI糖基化水平促进脂质外排,从而减少动脉粥样硬化的形成。

饲料中添加壳寡糖对异育银鲫非特异性免疫功能的影响

为了研究饲料中添加不同水平的壳寡糖(Chitosan oligosaccharide,β-1,4-寡糖-葡萄糖胺)对异育银鲫(Carassius auratus gibelio)非特异性免疫功能的影响,试验选择体重约为50 g健康的异育银鲫480尾,随机分成4个处理,每个处理3个重复,每个重复40尾异育银鲫。各组异育银鲫分别投喂含有0%(对照组)、0.25%、0.50%和0.75%的壳寡糖的试验饵料。试验周期为60 d。结果显示,与对照组相比,当异育银鲫养殖中添加0.50%和0.75%的壳寡糖可以使血清中丙二醛水平显著降低(P<0.05),血清溶菌酶活性和超氧化物歧化酶活性显著高于对照组和0.25%壳寡糖组(P<0.05),血清过氧化氢酶活性显著高于对照组(P<0.05)。研究表明,在异育银鲫养殖生产中添加适量的壳寡糖可以显著提高机体的非特异性免疫功能。综合养殖成本考虑,壳寡糖的最适添加量为0.50%~0.75%。

功能有机肥对樱桃番茄根结线虫病及产量的影响

利用海洋生物废弃物制备氨基酸和壳寡糖;以氨基酸、壳寡糖、金枫菌为主要的添加组分,开发生产了功能有机肥;以樱桃番茄为试验对象,以施用普通有机肥为对照,开展了田间小区试验,考察功能有机肥对根结线虫病的防治效果及增产情况。结果表明,与对照处理相比,施用功能有机肥的处理对根结线虫病的防治效果提高了63.28%~82.94%,樱桃番茄的产量提高了7.60%~27.29%。功能有机肥的开发应用,可以大幅减少农药的用量,为生产绿色樱桃番茄提供了保障。

The neuroprotective efects of peracetylated chitosan oligosaccharides againstβ‑amyloid‑induced cognitive defcits in rats

Chitosan oligosaccharides(COSs)have been reported to possess a broad range of activities such as antitumor,antioxidant and neuroprotective activities.In this study,the protective efects and mechanisms of peracetylated chitosan oligosaccharides(PACOs)against Aβ-induced cognitive defcits were investigated in Sprague–Dawley(SD)rats.PACOs treatment signifcantly improved the learning and memory function of Alzheimer’s disease(AD)rats and attenuated the neuron cell damage caused by Aβ.PACOs also markedly reduced the levels of lactate dehydrogenase(LDH)and Malondialdehyde(MDA)and decreased the phosphorylation of Tau protein to inhibit oxidative injury and infammatory responses in AD rats.Further studies indicated that PACOs may promote the repair of Aβinduced nerve damage and inhibit neuronal apoptosis mainly through regulating PI3K/Akt/GSK3βsignaling pathway.Consistently,the transcriptome analysis verifed that the diferentially expressed genes(DEGs)were mainly involved in neuron development and the PI3K-Akt signaling pathway.Taken together,peracetylated chitosan oligosaccharides(PACOs)have the potential to be developed into novel anti-AD agents targeting the cellular PI3K/Akt/GSK3βsignaling pathway.

壳寡糖和油菜素甾醇处理对番茄产量和品质的影响

为了探究壳寡糖与油菜素甾醇处理对番茄(Solanum lycopersicum L.)果实产量、感官品质、营养品质和风味品质的影响,本试验设置4个处理:对照组(CK)、壳寡糖处理组(0.5 g·L^(-1)COS)、油菜素甾醇处理组(0.5 g·L^(-1)BR)、复合处理组(0.5 g·L^(-1)COS+0.5 g·L^(-1)BR),对开花结果期的番茄植株进行叶面喷施。结果表明,壳寡糖与油菜素甾醇复合处理可以显著提高番茄产量;促进果实着色和软化;协同促进番茄中番茄红素、总胡萝卜素和维生素C的积累,相比CK分别提高88.3%、76.3%和28.6%。此外,二者复合处理可有效提高番茄中可溶性糖(葡萄糖和果糖)的含量,并降低有机酸(苹果酸和柠檬酸)的水平,从而提高番茄糖酸比。本研究结果为设施栽培下番茄产量和品质的提升提供了理论依据。

Preparation and Characterization of Florfenicol/Chitosan-stearic Acid Polymer Nanomicelle and Its Antibiotic Properties

Amphiphilic CS-SA polymers were prepared using the SA modified by small molecule water-soluble chitosan, and CS-SA nanomicelles and FF/CS-SA nanomicelles were prepared by using CSSA polymers as the material with dialysis-ultrasound method. CS-SA polymers, CS-SA nanomicelles, and FF/CS-SA nanomicelles were characterized by FT-IR, TGA, and SEM. Results showed that the SA was grafted to the amino of CS by amide bond. CS-SA nanomicelles and FF/CS-SA nanomicelles were spherical, smooth without fold. The influence of different molar ratio of FF to CS-SA polymers on the encapsulation efficiency and drug-loading rate determined the best molar ratio that was 1：1.09. In vitro release experiments, drug release performance study found that hydrophobic drug releasing from FF/CS-SA nanomicelles presented sustainedrelease. In vitro bacteriostasis experiments, when the concentration was higher than 4.98 mg/mL, FF/CSSA nanomicelles had antibacterial action and a positive correlation with concentration. The results revealed that amphiphilic chitosan derivative nanomicelles were carriers with broad prospects, increasing solubility of hydrophobic drugs and presenting sustained release for hydrophobic drugs, which provided a new research idea for drug delivery and targeted drug delivery of hydrohobic drugs.

不同聚合度壳寡糖单体在小鼠体内的吸收分布

荧光探针标记操作简单且荧光的检测灵敏度比紫外-可见光谱等传统方法高3~4个数量级,故本实验借助荧光探针测定并分析不同聚合度壳寡糖单体在小鼠体内的吸收分布。制备异硫氰酸荧光素标记的壳寡糖单体并灌胃小鼠,借助小动物活体光学成像系统和荧光定量检测,分析聚合度2~5的壳寡糖单体在小鼠体内吸收分布的差异性。结果显示,荧光标记的壳寡糖单体灌胃小鼠1 h后,在小鼠体内的荧光信号达到最大分布,壳寡糖能吸收入血,并跨过血脑屏障分布到脑组织中,主要分布在肾和肝脏中,其次分布在心和脾,少量分布在肺和脑;不同聚合度壳寡糖单体在肾和肝的分布量与聚合度呈正相关,而在血清、心、脾、肺和脑中的峰值分布量为壳二糖最多,壳四糖其次,壳五糖最少。明确不同聚合度壳寡糖单体的体内吸收分布的差异性,对于壳寡糖功能活性的构效关系研究具有一定的指导意义,能为壳寡糖的功能活性机制研究以及加快壳寡糖在食品功能性食品的开发和应用提供参考。