甲壳质及其衍生物的制备与应用

甲壳质是一种丰富的天然资源。近年来，甲壳质及其衍生物的开发应用受到国内外的重视，越来越多的产品将从实验室走向市场，本文介绍了甲壳质及其衍生物的制备方法及其在工业、农业、医药、环保、生物学等领域的应用。     

甲壳素及壳聚糖的应用

介绍了甲壳素及壳聚糖的性质,概述了近年来甲壳素及壳聚糖在生物工程、化工环保、生物医学、食品工业等领域的应用进展。     

甲壳素/壳聚糖在废水处理中的应用

综述了甲壳素和壳聚糖在含重金属离子废水、有色废水、食品加工废水和生活污水强化生物处理中的应用现状，认为甲壳素和壳聚糖是高效的生物吸附剂和絮凝剂，有颦在水处理领域获得更加广泛的应用。     

甲壳素和甲壳胺纤维质量的影响因素

概述了影响甲壳素和甲壳胺纤维质量的因素,如甲壳素和甲壳胺的品质、纺丝原液的溶剂选择及浓度的确定、凝固浴的确定;简述了通过化学改性来改善甲壳素和甲壳胺纤维性能;介绍了国内外为改善纤维质量所作的最新研究。     

Current state of chitin purification and chitosan production from insects

Chitin, and especially its deacetylated variant chitosan, has many applications, e.g. as carrier material for pharmaceutical drugs or as a flocculant in wastewater treatment. Despite its versatility and accessibility, chitin, the second most abundant polysaccharide on Earth, has so far been commercially extracted only from crustaceans and to a minor extent from fungi. Insects are a viable alternative source of chitin, but they have not been exploited in the past due to limited availability. Today however, for the sustainable production of animal feed, insect farming is being developed substantially. The availability of large quantities of insect biomass and chitin-rich side products such as exuviae and exoskeletons has been increasing. This review provides an overview of recently published studies of chitin extraction from insects, its subsequent conversion into chitosan and the primary analytical methods used to characterize insect-based chitin and chitosan. We have discovered a large number of research articles published over the past 20 years, confirming the increased attention being received by chitin and chitosan production from insects. Despite numerous publications, we identified several knowledge gaps, such as a lack of data concerning chitin purification degree and chitosan yield. Furthermore, analytical methods used to obtain physicochemical characteristics, structural information and chemical composition meet basic qualitative requirements but do not satisfy the need for a more quantitative evaluation. Despite the current shortcomings that need to be overcome, this review presents encouraging data on the use of insects as an alternative source of chitin and chitosan in the future. © 2020 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).     

Optimum parameters for production of chitin and chitosan from squilla (S. empusa)

Chitin and chitosan of high quality were produced from squilla, a by‐catch of Indian Ocean fisheries, by demineralization, deproteination, and deacetylation. Optimum conditions for the production of chitin and chitosan were determined. The quality of chitin was assessed from its ash and protein content. Ash content was below 1% after treatment with 4% HCl for 12 h at 50°C. A protein content of less than 1% could be achieved by treatment with 4% NaOH in 12 h but only at a temperature of 70°C or higher. Production of chitin was also tested by a three‐stage treatment with altering sequence of sodium hydroxide and hydrochloric acid (HCl–NaOH–HCl or NaOH–HCl–NaOH). This three‐step treatment appeared to be successful to achieve a mineral content and protein content below 1% within 30 h and at a temperature not exceeding 50°C. The chitin obtained under optimum conditions was tested for deacetylation using NaOH concentrations of 40 and 50% for 12–44 h at 30, 50 and 70°C. The chitosan obtained had a degree of deacetylation of 77–86%, a viscosity of 8.2–16.2 × 10² cps, solubility of 98%, and molecular weight of ? 1 × 10⁶ dalton. The data show that processing of squilla waste can lead to a high quality chitosan, useful for a broad range of applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 103: 3694–3700, 2007     

Entanglement network of chitin and chitosan in ionic liquid solutions

Concentrated solutions of a chitin from squid pens and of two commercial samples of chitosan were successfully prepared by using an ionic liquid 1‐butyl‐3‐methylimidazolium acetate as a solvent. The dynamic viscoelasticity data for the solutions exhibited rubbery plateaus, indicating the existence of entanglement network of chitin and chitosan in the solutions. To characterize the network, the values of the molecular weight between entanglements (M_e) for chitin and chitosan in the solutions were determined from the plateau moduli. Then the values of M_e in the molten state (M_e,melt), a material constant reflecting the inherent nature of polymer species, for chitin and chitosan were estimated to be 1.7 × 10³ and 3.0 × 10³, respectively. It was found that there was a significant difference in M_e,melt between chitin and chitosan. Compared with other polysaccharides such as cellulose and agarose in terms of the number of monosaccharide units between entanglements (N_unit), chitin had significantly smaller N_unit of 8, while chitosan had equivalent N_unit of 19. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2439–2443, 2013     

Chemical structure and compatibility of polyamide–chitin and chitosan blends

This work presents a comparative study of the compatibilization of four binary blends with slight differences in their chemical structures. The natural polymers chitin (QA) and chitosan (QN) are blended with polyamide 6 (PA6) and polyamide 66 (PA66). The results, obtained using differential scanning calorimetry, infrared spectroscopy, and light and scanning electron microscopy, gave the following compatibilization sequence: PA6/QN ≈ PA66/QN > PA6/QA > PA66/QA. This behavior could be related to the ability of QN to form hydrogen bonds and also to the capability of the packing of PA66. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 850–857, 2000     

壳聚糖及其衍生物在医药领域的应用

简要介绍了壳聚糖及其衍生物在医药领域的应用.展望了随着各种壳聚糖衍生物的合成成功,将有更多符合医药用标准的新型材料得到广泛应用.     

Preparation of acetylated chitosan sponges (chitin sponges)

Acetylated chitosan sponges (chitin sponges) were prepared according to acetylation time (25, 50, 75, and 100 h). As the acetylation time increased, the degree of acetylation increased, and a 75‐h acetylation time produced the highest degree of acetylation (DA). The surface morphologies of samples were examined by scanning electron microscopy. Sponge samples were shown by a water uptake ability test to have higher water absorption abilities. An in vitro biodegradation test showed that sponges with a higher DA were more susceptible to lysozyme hydrolysis. Acetylated chitosan sponges were further shown by an in vitro fibroblast proliferation test to have a higher degree of cell viability on increasing the DA, with 75 h exhibiting the maximum effect. The results showed that the wound healing effect of chitosan sponges can be controlled by the DA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Predicting the In Vivo Performance of Cardiovascular Biomaterials: Current Approaches In Vitro Evaluation of Blood-Biomaterial Interactions

The therapeutic efficacy of a cardiovascular device after implantation is highly dependent on the host-initiated complement and coagulation cascade. Both can eventually trigger thrombosis and inflammation. Therefore, understanding these initial responses of the body is of great importance for newly developed biomaterials. Subtle modulation of the associated biological processes could optimize clinical outcomes. However, our failure to produce truly blood compatible materials may reflect our inability to properly understand the mechanisms of thrombosis and inflammation associated with biomaterials. In vitro models mimicking these processes provide valuable insights into the mechanisms of biomaterial-induced complement activation and coagulation. Here, we review (i) the influence of biomaterials on complement and coagulation cascades, (ii) the significance of complement-coagulation interactions for the clinical success of cardiovascular implants, (iii) the modulation of complement activation by surface modifications, and (iv) in vitro testing strategies.     

氨基糖类表面活性剂--一类新型甲壳素衍生物的制备与性能

简要介绍了制备氨基糖类表面活性剂的基本原料———甲壳素、壳聚糖和甲壳低聚糖;较详细地阐述了两类氨基糖类表面活性剂———高分子壳聚糖类表面活性剂和甲壳低聚糖类表面活性剂的制备方法;重点论述了这两类氨基糖类表面活性剂的表面活性等功能性质,并简要提及了氨基糖类表面活性剂的构效关系;指出了氨基糖类表面活性剂研究存在的问题和应用前景。     

甲壳素铁卟啉和壳聚糖铁卟啉催化性能差异研究

用紫外和红外光谱技术考察了含氮生物高分子甲壳素和壳聚糖对四苯基铁卟啉的固载差异性,并研究了这种差异对四苯基铁卟啉催化空气氧化环己烷反应的影响。实验结果表明,壳聚糖比甲壳素通过分子间力对四苯基铁卟啉有更强的吸附固载能力,它们对四苯基铁卟啉的吸附平衡常数分别为9.68×104和6.80×104L/mol。这种吸附能力差异引起所固载的铁卟啉催化空气氧化环己烷的性能差别。在相同的催化反应条件下,载体对铁卟啉吸附能力越强的催化剂催化环己烷氧化生成酮和醇的速率越快,获得越高的产物选择性和催化剂转化数。     

Applications of chitin and its derivatives in biological medicine

Chitin and its derivatives-as a potential resource as well as multiple functional substrates-have generated attractive interest in various fields such as biomedical, pharmaceutical, food and environmental industries, since the first isolation of chitin in 1811. Moreover, chitosan and its chitooligosaccharides (COS) are degraded products of chitin through enzymatic and acidic hydrolysis processes; and COS, in particular, is well suited for potential biological application, due to the biocompatibility and nontoxic nature of chitosan. In this review, we investigate the current bioactivities of chitin derivatives, which are all correlated with their biomedical properties. Several new and cutting edge insights here may provide a molecular basis for the mechanism of chitin, and hence may aid its use for medical and pharmaceutical applications.     

Production of high‐quality chitin and chitosan from preconditioned shrimp shells

Chitin and chitosan with improved characteristics were produced from shrimp shell waste preconditioned by limited decay or by treatment with 0.016 mol L^?1 benzoic acid. Preconditioned shrimp shells were transparent, had a clean surface and were susceptible to demineralization and deproteinization using 0.68 mol L^?1 HCl and 0.62 mol L^?1 NaOH, respectively. The ash and protein residues in the final chitosan were about 0.2% and 0.4%, respectively, the viscosity was up to 7000 cps, and the solubility and transparency nearly 100%. In comparison with treatment at ambient temperature (30 °C) without preconditioning, the chemical consumption, the duration of the treatment, ash and protein residues was reduced to 75–25%, whereas viscosity and absence of insolubles improved by a factor of 2–3. Copyright © 2006 Society of Chemical Industry     

甲壳素、壳聚糖及其衍生物的研究和应用

甲壳素、壳聚糖及其衍生物是一种天然高分子产品，随着对其研究的深入发展，涉及的内容和应用范围也越来越广泛。从甲壳素、壳聚糖发展历史、性质、应用及发展趋势等几方面对其进行简要综述。     

Chelation of chitosan derivatives with zinc ions. I. O,N‐carboxymethyl chitosan

The chelation between O,N‐carboxymethyl chitosan (ONCMCh) and zinc sulfate in aqueous solution was studied by kinetic experiments and characterized by inductively coupled plasma (ICP) and UV spectrophotometry. The experimental data indicated that the chelating processes were greatly controlled by the reaction conditions (i.e., reaction time, temperature, and Zn²⁺ ionic and ligand concentrations). The consequence of chelating Zn²⁺ onto ONCMCh was the formation of complexes with different solubilities. The favorable complexes for ONCMCh‐Zn²⁺ chelate were at the low zinc ionic and ligand concentrations, as well as at the appropriate temperature. The evidence provided by the kinetic parameters and the changes in zinc concentration by ICP analysis further confirmed the plausible complexing mechanisms. While the formation of water‐soluble products was occasioned by the electrostatic attraction mechanism, the water‐insoluble products were predominantly formed by chelation of Zn²⁺ with O,N‐carboxymethyl chitosan. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2246–2253, 2000     

甲壳素、壳聚糖及其衍生物在生物医药领域中的应用研究近况

随着甲壳素、壳聚糖及其衍生物研究的迅速发展,其研究内容和应用范围越来越广泛。本文主要介绍了它的发展,性质,提取及加工方法以及其在生物医药领域方面的应用和发展研究近况。     

Effects of chitin and its derivative chitosan on postharvest decay of fruits: a review

Considerable economic losses to harvested fruits are caused by postharvest fungal decay during transportation and storage, which can be significantly controlled by synthetic fungicides. However, considering public concern over pesticide residues in food and the environment, there is a need for safer alternatives for the control of postharvest decay to substitute synthetic fungicides. As the second most abundant biopolymer renewable source in nature, chitin and its derivative chitosan are widely used in controlling postharvest decay of fruits. This review aims to introduce the effect of chitin and chitosan on postharvest decay in fruits and the possible modes of action involved. We found most of the actions discussed in these researches rest on physiological mechanisms. All of the mechanisms are summarized to lay the groundwork for further studies which should focus on the molecular mechanisms of chitin and chitosan in controlling postharvest decay of fruits.     

Chemical modification of chitosan: synthesis and biological activity of new heterocyclic chitosan derivatives

BACKGROUND: Numerous works have been published on the chemical modification of chitosan; this polymer is still being modified, leading to various derivatives with improved properties. In the present study, heterocyclic aldehydes including furan‐2‐carbaldehyde, 5‐methylfuran‐2‐carbaldehyde, 3‐pyridine carboxyaldehyde, benzo[d][1,3]dioxole‐5‐carbaldehyde and 4‐oxo‐4H‐chromene‐3‐carbaldehyde were reacted with chitosan by a reductive alkylation reaction to produce for the first time five new N‐heterocyclic chitosan derivatives to improve the biological activity of chitosan against the most important economic plant pests including fungi and insects, in particular the cotton leafworm Spodoptera littoralis. RESULTS: The chemical structures of the synthesized compounds were confirmed by ¹H NMR spectroscopy and the degree of substitution ranged from 0.30 to 0.43. The fungicidal assessment was investigated in vitro using a mycelia radial growth inhibition technique against soil‐borne pathogenic fungi Fusarium oxysporum and Pythium debaryanum and the rice leaf blast Pyricularia grisea. The results showed that N‐[(5‐methylfuran‐2‐yl)methyl] chitosan was the most active against P. grisea with an EC₅₀ value of 0.919 mg mL^?1 while N‐(benzo[d][1,3]dioxol‐5‐ylmethyl) chitosan and N‐(methyl‐4H‐chromen‐4‐one) chitosan exhibited the most potent fungicidal activity against P. debaryanum and F. oxysporum. An insecticidal bioassay against the larvae of S. littoralis showed that N‐(methyl‐4H‐chromen‐4‐one) chitosan exhibited a significant growth inhibition and antifeedant activity among the synthesized compounds. CONCLUSION: The chemical modification of chitosan molecule with a heterocyclic moiety led to an enhancement in the biological activity against the plant pathogenic fungi F. oxysporum, P. debaryanum and P. grisea and the cotton leafworm insect S. littoralis. Copyright © 2007 Society of Chemical Industry