(3,5-Dimethyl-1H-pyrazol-1-yl){3-[(3,5-dimethyl-1H-pyrazol-1-yl)carbon-yl]-5-methyl-indolizin-1-yl}methanone.

There are two independent mol-ecules in the asymmetric unit of the title compound, C21H21N5O2. In each mol-ecule, the indolizine ring system is essentially planar, with r.m.s. deviations of 0.030 and 0.028 Å. The dihedral angles between the indolizine ring system and the pyrazole rings are 54.7 (3) and 8.6 (3)° in one mol-ecule and 54.4 (3) and 6.6 (3)° in the other. In the crystal, weak C-H⋯O and C-H⋯N hydrogen bonds link mol-ecules, forming a two-dimensional network parallel to (100).

[Structural characteristics of humic acids from a long-term petroleum contaminated soil].

Petroleum contamination in soil decreases with the increase in the distance of soil to the drilling well. Accordingly, an abandoned petroleum well which had been exploited for about twenty years in Songyuan city of Jilin Province, China, was selected to investigate the structural characteristics of soil humic acids (HAs) under different petroleum contamination levels. Surface (0-20 cm) soil samples were collected at 0.5, 1.5, 3.5, 5.5 and 7.5 m deep from well head, and the petroleum contents were respectively 153.3, 148.4, 129.2, 50.5 and 5.62 g x kg(-1). HAs were extracted with 0.1 mol x L(-) NaOH and 0.1 mol x L(-1) Na4 P2O7 and were characterized with elemental analysis, Fourier transformed infrared (FTIR) spectroscopy and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy. Results showed that the atomic C/H, O/C and (N+O) /C ratios of HAs increased from 0.74, 0.41 and 0.45 for 7.5 m to 0.80, 0.83 and 0.88 for 0.5 m, respectively. The relative intensity of the peaks assigned to aliphatic carbon (2 921, 2 851 and 1 454 cm(-1)) in the FTIR spectra gradually decreased with increasing contamination levels, while that of the peak assigned to aromatic C(1 600 cm(-1)) increased, and the calculated absorption intensity ratio of 2 921 to 1 600 cm(-1) (2 921/1 600) declined from 0.22 for 7.5 m to 0.11 for 0.5 m. The solid-state 13C NMR data suggested that the relative content of alkyl C(0-50 ppm ) decreased from 49.9% for 7.5m to 30.9% for 0.5 m, while that of O-alkyl C(50-110 ppm), aromatic C(110-160 ppm) and carboxyl C(160-190 ppm) increased respectively from 20.1%, 13.1% and 14.3% to 28.0%, 18.8% and 19.3%. These results showed substantial chemical, structural, and molecular differences among these HAs. The aliphaticity and hydrophobicity of HAs decreased while aromaticity and polarity increased with the increase in petroleum content. Namely, HAs tended to become aged in molecular structure. Therefore, it is imperative to renew and activate the aged HAs by adopting appropriate measures for the remediation of petroleum contaminated soil.

A novel pyrazole-containing indolizine derivative suppresses NF-κB activation and protects against TNBS-induced colitis via a PPAR-γ-dependent pathway.

The nuclear factor-κB (NF-κB)-mediated activation of macrophages plays a key role in mucosal immune responses in Crohn's disease (CD). Moreover, increasing evidence shows that the activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) exerts satisfactory anti-inflammatory effects in experimental colitis models, mostly by suppressing NF-κB-mediated macrophage activation. Therefore, exploring therapeutic strategies to activate PPAR-γ and inhibit the NF-κB pathway in colonic macrophages holds great promise for the treatment of CD. In this study, five novel pyrazole-containing indolizine derivatives (B1, B2, B3, B4 and B5) were successfully synthesized and characterized, and their anti-inflammatory activities for CD treatment were also investigated. Among the five compounds, compound B4 effectively decreased the NF-κB-mediated production of the pro-inflammatory cytokine TNF-α in LPS-stimulated peritoneal macrophages. Moreover, compound B4 significantly ameliorated 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis symptoms, including body weight loss, colonic pathological damage and inflammatory cell infiltration. The results of western blotting and luciferase reporter assays indicated that compound B4 activated PPAR-γ and subsequently suppressed NF-κB activation. Conversely, the addition of the PPAR-γ antagonist GW9662 abrogated the anti-inflammatory effects of compound B4 both in vitro and in vivo. In summary, compound B4 activated the PPAR-γ pathway to inhibit downstream NF-κB signaling, which alleviated experimental colitis. Thus, this compound may serve as a potential therapeutic agent for patients with CD.

[Responses of enzyme activities in different particle-size aggregates of paddy soil in Taihu Lake region of China to long-term fertilization].

Taking a long-term fertilized paddy soil in Taihu Lake region as research object, the enzyme activities in <2, 2-20, 20-200, and 200-2000 microm aggregates under no fertilization (NF), chemical fertilization (CF), chemical fertilization plus straw return (CFS), and chemical fertilization plus pig manure (CFM) were investigated. Fertilization promoted the formation of 200-2000 microm aggregates significantly. The enzyme activities differed with aggregates' particle-size. Urease and invertase activities were the highest in <2 microm aggregates, whereas the activities of cellulase, polyphenoloxidase and FDA hydrolase were the highest in 200-2000 microm aggregates. Fertilization, especially the combined fertilization of inorganic and organic fertilizers, increased the activities of urease, invertase, cellulase and FDA hydrolase in 200-2000 microm aggregates significantly. With the geometric mean (GMea) of the five test enzyme activities as the integrative index of soil enzyme activities, it was found that under fertilization, the GMea was significantly higher in 200-2000 microm aggregates, suggesting the high sensitivity of enzyme activities in larger particle-size aggregates to fertilization practices. Long-term inorganic plus organic fertilization could enhance the soil bio-function via the promotion of the formation of larger particle-size aggregates and the enzyme activities in these aggregates.