Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest forestry University, Kunming, Yunnan 650224, China; Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest forestry University, Kunming, Yunnan 650224, China.
Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest forestry University, Kunming, Yunnan 650224, China; Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest forestry University, Kunming, Yunnan 650224, China.
Int J Biol Macromol. 2024 Jan;255:128056. doi: 10.1016/j.ijbiomac.2023.128056. Epub 2023 Nov 13.
The bioactivities of pristine chitosan are considerable weak compared with the commercial chemicals, which has restricted its broad application prospects in food packaging and preservation. In order to obtain a safe, biologically derived fruits preservative with excellent antifungal properties, dehydroabietic acid (DHA) was used to modify chitosan (CS). The structural characterization of modified chitosans were identified by FTIR and H NMR spectra. The XRD pattern showed the modified chitosan changed the crystal structure due to the modification of the amino and/or hydroxyl groups on the chitosan. Their antifungal activities against Penicillium digitutim and Penicillium italicum were investigated in vitro using the radial growth assay and the minimal inhibitory concentration assay. The study also examined the differences in antifungal effect among three modified chitosans. The results showed that DHA only conjugated thehydroxyl group at C-6, bearing free amino group at C-2, exhibited the strongest antifungal effect, with a minimum inhibitory concentration (MIC) of 200 μg/mL. In addition, a comparison of the antifungal activity of the modified compounds with different concentrations of Imazalil demonstrated that the modified biologic antifungal agent was as effective as Imazalil. CSDA can achieve 100 % inhibition of P. digitutim at concentrations >100 μg/mL and remain unchanged for a long time. Because CSDA can enhance the shelf life of longans, DHA-CS, chitosan derivatives, have tremendous promise for use in fruits preservation.
与商业化学品相比，壳聚糖的生物活性相当弱，这限制了其在食品包装和保鲜中的广泛应用前景。为了获得具有良好抗真菌性能的安全、生物衍生的水果保鲜剂，用去氢枞酸（DHA）对壳聚糖（CS）进行了修饰。通过傅里叶变换红外光谱（FTIR）和核磁共振（H NMR）谱对修饰壳聚糖的结构特征进行了鉴定。X 射线衍射（XRD）图谱表明，由于壳聚糖氨基和/或羟基的修饰，修饰壳聚糖改变了其晶体结构。采用体外径向生长法和最小抑菌浓度法（MIC）研究了它们对指状青霉和意大利青霉的抗真菌活性。同时还研究了三种修饰壳聚糖之间抗真菌效果的差异。结果表明，DHA 仅与 C-6 位上的羟基发生共轭，C-2 位上带有游离氨基，表现出最强的抗真菌效果，最小抑菌浓度（MIC）为 200μg/mL。此外，对不同浓度的改性化合物与抑霉唑的抗真菌活性进行了比较，结果表明，改性生物抗真菌剂与抑霉唑同样有效。CSDA 在浓度>100μg/mL 时可实现对 P. digitutim 的 100%抑制，且长时间保持不变。由于 CSDA 可以延长龙眼的保质期，因此 DHA-CS，壳聚糖衍生物，在水果保鲜方面具有巨大的应用前景。
