Surface coating of antifouling materials on the substrates offers convenient strategies and great opportunities to improve their biocompatibility and functions of host substrates for wide biomedical applications. In this work, we present a general surface zwitterionization strategy to improve surface biocompatibility and antifouling properties of titanium (Ti) by grafting zwitterionic poly(sulfobetaine methacrylate) (polySBMA). This method also demonstrates its general applicability to graft polySBMA onto Ti surface using different anchoring agents of dopamine and silane. The resulting polySBMA grafted from dopamine- (pTi-D-pSBMA) and silane-anchored titanium surfaces (pTi-Si-pSBMA) surfaces exhibit superlow fouling ability to highly resist the adhesions of plasma proteins, platelets, erythrocytes, leukocytes, human fibroblast (HT1080), E. coli, and S. epidermidis. The interfacial properties of the surface-modified Ti surfaces are analyzed and correlated with their antifouling properties. The new method and materials provide a more general, flexible, and robust way to produce an excellent nonfouling surface with adjustable interfacial structures of grafted polymers, which hopefully can be expanded to wider applications based on both the structure and surface superiorities.
Fusarium, a large genus of filamentous fungi, is widely distributed in soil and plants. Fusarium is a prolific source of novel chemical constituents with various bioactivities. In search for antibiotics from soil and endophytic fungi, the secondary metabolites of Fusarium avenaceum SF-1502 and Fusarium proliferatum AF-04 were investigated. An alkaloid (1), a depsipeptide (6), and five sesquiterpenoids (7−11) were isolated from the extracts of the soil fungus F. avenaceum SF-1502. Three alkaloids (2−4), a depsipeptide (5), three sesquiterpenoids (9, 11, and 12), a sesterterpene (13), and four 1,4-naphthoquinones (14− 17) were also separated from the extract of the green Chinese onion derived fungus F. proliferatum AF-04. Fusaravenin (1) represents the first example of a natural naphthoisoxazole-type zwitter-ionic alkaloid, a naphthoisoxazole formic acid connected with a morpholino carbon skeleton. Cyclonerotriol B ( 7) is a new cyclonerane sesquiterpene. Another new sesquiterpene, 3βhydroxy-β-acorenol ( 12), possesses an acorane framework. The known compounds 9 and 11 were found from both fungi. The structures of the new compounds were determined via extensive HR-ESI-MS and comparison between experimental and calculated NMR results. The biological properties of 1−5 and 7−17 were evaluated against eight anthropogenic bacteria, while 1 and 7−11 were also screened for inhibitory effects against four plant pathogen bacteria. The known compounds 8, 9, and 14− 17 showed potent antibacterial activities toward some of the tested anthropogenic bacteria.
ABSTRACT:The high oil magnetic composite resin, which is a low crosslinking resin, was synthesized by conventional suspension copolymerization in the present work. The effect of the monomer ratio, crosslinker, initiator, modified Fe 3 O 4 , and reaction time on oil absorptivity of the resin and defined optimum reaction condition were studied. The highest oil absorptivity of the resin was about 20 g/g in chloroform and 10.5 g/g in toluene when the extent of modified Fe 3 O 4 was 5%. Infrared (IR), X-ray diffractometer (XRD), synthetic themoanalyzer, laser particle size analyzer, and vibrating-sample magnetometer (VSM) were used to study the properties of the oil-absorbing magnetic composite resin. The magnetic composite resin can be recovered after conveniently and rapidly absorbing oil by magnetic separation techniques without excluding other mechanical techniques.
Two types of novel benzoxazine-based phenolic resins from phenol-furfural (PFB) and cardanol-furfural (CFB) resins had been synthesized and the highly thermally stable polybenzoxazines were obtained by the thermal cure of the corresponding benzoxazine-based phenolic resins. The chemical structure of benzoxazine-based phenolic resins derived from renewable resources was confirmed by Fourier transform infrared (FTIR), 1 H NMR, and gel permeation chromatography (GPC). FTIR spectrum and differential scanning calorimetry (DSC) showed that the monomers were thermally initiated and polymerized via ring-opening polymerization. Thermogravimetric analysis indicated that the incorporation of furan groups could enhance the char yield and thermal stability. However, the long alkyl side chain from cardanol could increase the toughness, while decreasing the char yield and thermal stability.
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