pH-responsive lignin-based magnetic nanoparticles for recovery of cellulase.

Enzymatic hydrolysis of lignocellulose to produce bioethanol by cellulase is an important method to alleviate the energy crisis. In this paper, in order to overcome the shortcomings of low efficiency, high cost and easy deactivation of cellulase in the process of bio-refinery, pH-responsive lignin-based magnetic nanoparticles (Fe3O4/LSQA) were synthesized to immobilize and recover cellulase. It was shown that a high immobilization ratio of 55.52% for cellulase was obtained. Meanwhile, the desorption ratio was 68.27% by adjusting the pH of the system. After five reusing cycles, the desorbed cellulase retained 31.79% of the relative activity due to the pH responsiveness of Fe3O4/LSQA. These results not only provide a new idea for the recycling of cellulase, but also broaden the application of industrial lignin and increase the extra value.

Anti-inflammatory effect of novel andrographolide derivatives through inhibition of NO and PGE2 production.

Andrographolide (1) is a major diterpene lactone exhibiting anti-inflammatory effects and is found in the plant Andrographis paniculata (Burm. f) Nees, which is widely used in Traditional Chinese Medicine. Synthesis of more effective drugs from andrographolide is very interesting and can prove to be highly useful. In this study, we investigated the anti-inflammatory effects of andrographolide and its derivatives (compounds 2-6) through dimethylbenzene-induced ear edema in mice. Substances under study were administrated intragastrically and the structure-activity relationship was analyzed. Results showed that compounds 5 and 6 significantly inhibited ear edema compared with compound 1 (p<0.05), indicating that the introduction of p-Chlorobenzylidene to C-15 of compound 2 enhances the anti-inflammatory effect. Moreover, compound 6 exhibited the strongest anti-inflammatory effect against ear edema in mice (79.4%; 1.35 mmol/kg, ig) and paw edema in rats (50.4%; 0.90 mmol/kg, ig). In addition, compound 6 significantly (p<0.05) inhibited granuloma formation and reduced the increase in vascular permeability induced by peritoneal injection of 0.6% acetic acid solution in mice. Findings indicate that compound 6 exerts its enhanced anti-inflammatory effects by decreasing serum iNOS activity, NO production, and PGE(2) production.

Synthesis of 3beta, 7alpha, 11alpha-trihydroxy-pregn-21-benzylidene-5-en-20-one derivatives and their cytotoxic activities.

A series of novel 3beta, 7alpha, 11alpha-trihydroxy-pregn-21-benzylidene-5-en-20-one derivatives were synthesized and characterized by NMR, HRMS. The pregnenolone (1) was first biotransformed by Mucor circinelloides var lusitanicus to 3beta, 7alpha, 11alpha-trihydroxy-pregn-5-en-20-one (3), then 3 was treated with various benzaldehydes to produce 3beta, 7alpha, 11alpha-trihydroxy-pregn-21-benzylidene-5-en-20-one derivatives. These derivatives showed remarkable activity against EC109 cells. The absolute configuration of 3 was also confirmed by signal-crystal X-ray analysis.