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In the present world chitin is used enormously in various fields, such as biopharmaceuticals, medical and clinical bioproducts, food packaging, etc. However, its development has been curbed by the impaired performance and cumbersome dissolution process when chitin materials are dissolved and regenerated by physical or chemical methods. To further obtain the regenerated chitin fiber material with improved performance, silk fibroin was introduced into the chitin matrix material, and chitin/silk fibroin biocompatible composite fibers were obtained by formic acid/calcium chloride/ethanol ternary system and top-down wet spinning technology. The produced composite fibers outperformed previously reported chitin-silk composites in terms of the tensile strength (160 MPa) and failure strain (25%). The fibers also performed good cell compatibility and strong cellular affinity for non-toxicity. The cell viabilities of the fibers were about 20% greater than those of silk fiber after three days of co-culture with NIH-3T3. Furthermore, no hemolysis occurs in the presence of chitin/silk fibers, demonstrating their superior hemocompatibility. The fibers had a hemolysis index as low as 1%, which is far lower than the acceptable level of 5%. The material offers prospective opportunities for biomaterial applications in anticoagulation, absorbable surgical sutures, etc. [ABSTRACT FROM AUTHOR]

Sustainable materials fabricated from natural polymers have attracted much attentions because of their multiple advantages like abundant renewable resource, biocompatibility, biodegradability, and nontoxicity, while their actually application often restricted by mechanical properties. Chemical crosslinking method was usually used to improve the mechanical properties of cellulose materials such as hydrogel, film, aerogel, and so forth. Here, cellulose fibers were fabricated from cellulose solution in alkali/urea aqueous solvent by chemical crosslinking with epichlorohydrin in a PVC hose. The chemical crosslinked cellulose fibers exhibited smooth surface and circular cross‐section. Their tensile strength increased from 128 to 368 MPa by adjusting cellulose concentration, ECH concentration, and draw ratio. The crystallinity of the fibers changed from 43.1% to 49.8% after drawing process. Meanwhile, the fibers exhibited a brighter color after dyeing than the viscose rayon. This work promising an avenue for preparation of mechanical strong cellulose fibers. [ABSTRACT FROM AUTHOR]

The use of dopamine to synthesize melanin as a natural dye on fabrics has the disadvantages of complicated processing, long processing time, and high cost. This study simplifies the processing conditions of the oxidative polymerization of dopamine and develops wool fabric melanin coatings with different finishing effects by adjusting the reaction time. The results of computer color matching, ultraviolet (UV) protection properties, and color fastness indicated that the treated wool fibers were effectively dyed, and they achieved UV resistance properties comparable to those realized in other studies in a relatively short time. The degree of lightness (L) and UV protection factor of the treated fabric reached up to 13.3 and 80+, respectively. Samples W/PDA 60 and W/PDA 120 absorbed more than 95% of the UV light. The color fastness was greater than Grade 4. The Fourier infrared spectrum and X‐ray diffraction studies revealed that the chemical and crystalline structures of the wool fiber did not change significantly after the treatment. The breaking strength of samples W/PDA 60 and W/PDA 120 was about 50% higher than that of the original wool fabric. This efficient and simple method provides a feasible and promising solution for the color deepening and UV finishing of high value‐added wool products. It can be a potential choice for upgrading the printing and dyeing industries from the perspective of ecological protection. [ABSTRACT FROM AUTHOR]

In this study, in order to improve mechanical properties of cotton fabrics, nano‐micro sized calcium carbonate (CaCO3) was deposited in situ on cotton fabrics. The mechanical properties, surface morphology, crystalline index, infrared spectrum, thermal property, and wettability of the deposited fabrics were measured and discussed. The results showed that the breaking strength of cotton fabric increased by about 10% after in situ deposition of nano‐micro calcium carbonate. After ultrasonic washing, the strength of cotton fabric deposited CaCO3 was still increased by about 10%. The crystallinity of the cotton fabric deposited with calcium carbonate increased from 76% to 84%. The hydrogen bond between cellulose molecules and calcium carbonate was confirmed by infrared spectroscopy. The hydrophilicity and thermal properties of cotton fabric were not significantly influenced by calcium carbonate deposition. This provides a new idea for improving the mechanical properties of cotton fabric. [ABSTRACT FROM AUTHOR]

In the present world chitin is used enormously in various fields, such as biopharmaceuticals, medical and clinical bioproducts, food packaging, etc. However, its development has been curbed by the impaired performance and cumbersome dissolution process when chitin materials are dissolved and regenerated by physical or chemical methods. To further obtain the regenerated chitin fiber material with improved performance, silk fibroin was introduced into the chitin matrix material, and chitin/silk fibroin biocompatible composite fibers were obtained by formic acid/calcium chloride/ethanol ternary system and top-down wet spinning technology. The produced composite fibers outperformed previously reported chitin-silk composites in terms of the tensile strength (160 MPa) and failure strain (25%). The fibers also performed good cell compatibility and strong cellular affinity for non-toxicity. The cell viabilities of the fibers were about 20% greater than those of silk fiber after three days of co-culture with NIH-3T3. Furthermore, no hemolysis occurs in the presence of chitin/silk fibers, demonstrating their superior hemocompatibility. The fibers had a hemolysis index as low as 1%, which is far lower than the acceptable level of 5%. The material offers prospective opportunities for biomaterial applications in anticoagulation, absorbable surgical sutures, etc.

A protecting-group-free route for the total synthesis of (-)-lycopodine was demonstrated in only 8 steps from Wade's fawcettimine enone (12 steps from commercial availiable (R)-(+)-pulegone). The key core of this alkaloid was constructed through a phosphoric acid promoted and highly stereocontrolled alkyne aza-Prins cyclization reaction, synchronously establishing the bridged B-ring and the C13 quaternary stereocenter. Importantly, the synthesis further features a new efficient approach for the preparation of other lycopodine-type alkaloids.

The first bioinspired total syntheses of (-) kravanhins A and C were accomplished from a labdane diterpenoid derivative. The key reactions involve a photooxidation and a one-pot sequential aldol cyclization and lactonization, which provide a new plausible biosynthetic pathway for the kravanhins and other symbiotic members., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The first asymmetric total syntheses of (+)-dihydrolyfoline and (-)-5-epi-dihydrolyfoline have been achieved in five and six steps with 4.6% and 14% overall yields, respectively, in which the chiral biaryl axes were constructed in a highly regioselective and stereoselective manner via a biogenetic enzymatic oxidative couplings of phenols, and the requisite quinolizidinone cores were prepared by an enzymatic Mannich reaction.