Design and Synthesis of Dimethylaminomethyl-Substituted Curcumin Derivatives: Potent Anti-Inflammatory, Anti-Oxidant, and Radioprotection Activity, Improved Aqueous Solubility Compared with Curcumin.

Although the wide variety of bioactivities of curcumin has been reported by researchers, the clinical application of curcumin is still limited due to its poor aqueous solubility. In view of this, a series of dimethylaminomethyl-substituted curcumin derivatives were designed and synthesized (compounds 1-15). Acetate of these derivatives were prepared (compounds 1a-15a). The Mannich reaction and aldol condensation reaction are the main reactions involved in this study. Compounds 6, 10, 12, 3a, 5a, 6a, 7a, 8a, 10a, 11a, 12a, 13a, 14a, and 15a exhibited better in vitro anti-inflammatory activity compared to curcumin in the RAW264.7 cell line. Compounds 5, 1a, 5a, 8a, and 12a exhibited better in vitro antioxidant activity compared to curcumin in the PC 12 cell line. Compounds 11, 13, 5a, 7a, and 13a exhibited better in vitro radiation protection compared to curcumin in the PC 12 cell line. The aqueous solubilities of all the curcumin derivative acetates were greatly improved compared to curcumin.

Skeleton Synthesis of a Plant-Derived Radioprotective Alkaloid Born to Produce a Novel Fused Heterocycle.

Alkaloids are a material treasure bestowed on humans by nature owing to their numerous biological activities. Orychophragine D, an alkaloid isolated from the seeds of Orychophragmus violaceus was identified as bearing a novel skeleton and proved to have an excellent radioprotective effect. Different from the common alkaloid structure, the main block of orychophragine D is constructed of an oxotriazine and an oxopiperazine, which are connected in parallel by a C-N bond. In this paper, a preparation method for the novel heterocycle skeleton of orychophragine D is proposed for the first time. N-Boc-L-serine was utilized as the original material to complete the preparation with 11 steps in a 13% overall yield. A hydroxyl group was established on the side chain of the skeleton as the reaction site for researchers to conduct further structural modification or derivatization.

Polypyrrole/Schiff Base Composite as Electromagnetic Absorbing Material with High and Tunable Absorption Performance.

In recent years, Schiff base-related conjugated systems have received extensive attention, but little research has been done in the field of electromagnetic materials. In this work, an organic conjugated system based on polypyrrole/hydrazone Schiff base (PPy/HSB) composites was constructed via a Schiff base synthetic route and their electromagnetic behavior was investigated. The electromagnetic response of PPy/HSB complexes demonstrates fine electromagnetic absorption performance. When the filler loading is 30 wt% in a paraffin matrix, an absorption peak of -43.1 dB was achieved and its effective absorption bandwidth (EAB) was located in the range of 10.88-18.0 GHz. The electromagnetic response behavior of PPy/HSB complexes is explained by models involving electronic structure, multi-polarization and conductive network. The mechanisms of PPy/HSB complexes formation and HSB crystallization are also discussed through the compatibility of PPy/HSB and the structure of HSB. Moreover, the morphology transformation of HSB in the PPy/HSB systems has been studied. This study opens the exploration of organic-dielectric conjugated systems in the field of electromagnetic materials, and significantly broadens the application range of organic-dielectric-dielectric composites.

Polystyrene-Modulated Polypyrrole to Achieve Controllable Electromagnetic-Wave Absorption with Enhanced Environmental Stability.

The moderation of the dielectric properties of polymer composites and their environmental stability need to be considered comprehensively in the design of microwave-absorbing materials. In this work, polypyrrole/polystyrene (PPy/PS) composited particles were synthesized through a facile in situ bulk polymerization procedure. The PS component can be modulated conveniently by controlling the polymerization time. FTIR and Raman analyses disclosed that the PS component was immobilized in PPy via covalent bonds. The electromagnetic characterization results indicated that the dielectric properties and, thus, the microwave absorption could be controlled when the styrene polymerization was prolonged from 6 h (PPy-6) to 19 h (PPy-19). The composite PPy-19 displayed an optimal reflection loss of -51.7 dB with a matching thickness of 3.16 mm, and the effective absorption bandwidth (EAB) even reached 5.8 GHz at 2.4 mm. The PS component endowed PPy/PS composites with more robust environmental stability than homogeneous PPy. After being exposed to air for 365 days and hydrothermally treated at 100 °C for 12 h, PPy-19 still exhibited a reflection loss superior to -20 dB. The present work provides a new insight into the adjustment of the electromagnetic properties of PPy composites to fabricate high-performance microwave absorbers with superior environmental stability.

Resistance Risk Evaluated by Metaflumizone Selection and the Effects on Toxicities Over Other Insecticides in Spodoptera exigua (Lepidoptera: Noctuidae).

Metaflumizone is a novel semicarbazone insecticide. It functions as a sodium channel blocker insecticide (SCBI) with excellent insecticidal activity on most economically important lepidopterous pests. This study assessed the resistance risk of Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) to metaflumizone in the laboratory and the effects of metaflumizone selection on toxicities to other insecticides. Spodoptera exigua collected from a field population at Huizhou in 2012 were successively challenged by metaflumizone to evaluate the risk of resistance evolution. Twelve generations of selection increased resistance to metaflumizone by 3.4-fold and threshold trait analysis revealed that the realized heritability (h2) of this resistance was 0.086. When h2 was equal to 0.086 and 90% of individuals were killed at each generation, LC50 to metaflumizone increased by 10-fold after 15 generations. The selection by metaflumizone did not increase the resistance to indoxacarb, chlorantraniliprole, spinosad, methomyl, or endosulfan, suggesting a lack of cross-resistance. However, metaflumizone challenge upheld the recession of resistance to emamectin benzoate, chlorfluazuron, and tebufenozide. The block of resistance drops by metaflumizone exposure implied a possible cross-resistance between metaflumizone and these three insecticides. These results contribute to integrated resistance management of S. exigua.

NLRP3 inflammasome is essential for the development of chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is now recognized as an inflammatory disease and the nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasome was speculated to participate into its pathophysiological process, however, a direct role of NLRP3 has yet to be clearly shown. METHOD: COPD model was established by tobacco inhalation, COPD modeling and NLRP3 knockout mice were treated with similar dose and duration of tobacco inhalation for 12 months, the lung function, lung damage and immune responses were evaluated between control, wild type COPD and NLRP3 knock out C57B1/6 mice. RESULTS: 10 months after tobacco inhalation, the respiratory system resistance indexes of COPD mice was significantly higher than that of control and NLRP3 knockout mice (2.8 ± 0.5 vs. 1.2 ± 0.3 and 1.3 ± 0.1 cm H2O ml(-1) s(-1), P < 0.05); the respiratory system compliance indexes of COPD was significantly lower than that of control and NLRP3 knockout mice (0.31 ± 0.02 vs. 0.43 ± 0.04, and 0.39 ± 0.01 ml/cm H2O); the NLRP3 knockout mice displayed no distinguishable pathological damage in the lung. Of the broncho-alveolar lavage fluid (BALF), the concentration of IL-1 and IL-18 of the COPD were significantly higher than that of control and NLRP3 knockout mice (IL-1: 286.8 ± 1.7 vs. 23.8 ± 2.1 and 24.2 ± 1.3 pg/mL, P < 0.05; IL-18: 104.5 ± 4.2 vs. 12.6 ± 2.1 and 15.7 ± 2.8 pg/mL, P < 0.05); the total numbers of macrophages, eosinophils, lymphocyte and neutrophil of control, COPD and NLRP3 knockout mice were 2.3 ± 0.4, 0.5 ± 0.2, 10.3 ± 3.4 and 2.8 ± 2.7; 8.7 ± 1.1, 12.5 ± 1.1, 45.3 ± 3.3 and 29.2 ± 4.2; and 3.2 ± 0.7, 1.8 ± 0.4, 18.1 ± 1.1 and 12.8 ± 3.4 × 10(4) mL, respectively; the rates of NLRP3 positive macrophages in the BALF of control, COPD and NLRP3 knockout mice were 5.0 ± 1.0%, 78.1 ± 9.2% and 2.0 ± 0.9%, respectively. CONCLUSION: NLRP3 inflammasome is essential for the development of COPD and blockade of NLRP3 might be a possible therapeutic strategy for COPD.