Levels of Crotonaldehyde and 4-hydroxy-(E)-2-nonenal and Expression of Genes Encoding Carbonyl-Scavenging Enzyme at Critical Node During Rice Seed Aging

The critical node(CN) is an important stage during seed aging, which is related to effective genebank conservation. Previous studies have demonstrated that proteins undergo carbonylated modification at the CN in rice, indicating oxidative damage. However, the levels of reactive carbonyl species(RCS) and the associated scavenging system at the CN are largely unknown. In this study, we optimized methods for the extraction and analysis of RCS from dry rice embryos. In order to acquire seeds at the CN, rice seeds were subjected to natural conditions for 7, 9, 11 and 13 months, and the seed germination rates were reduced to 90%, 82%, 71% and 57%, respectively. We chose the stage with seed germination rate of 82% as the CN according to the rice seed vigor loss curve. The levels of crotonaldehyde and 4-hydroxy-(E)-2-nonenal(HNE) were significantly increased at the CN. In addition, genes encoding carbonyl-scavenging enzyme, including Os ALDHs and Os AKRs, were significantly down-regulated at the CN, and reductions in the expression of Os ALDH2-2, Os ALDH2-5, Os ALDH3-4, Os ALDH7, Os AKR1 and Os AKR2 in particular could be responsible for RCS accumulation. Thus, the accumulations of crotonaldehyde and HNE and down-regulation of genes encoding carbonyl-scavenging enzyme might be related to an accelerating loss of seed viability at the CN.

SYNTHESIS OF POLYMER-STABILIZED PLATINUM/RUTHENIUM BIMETALLIC COLLOIDS AND THEIR CATALYTIC PROPERTIES FOR SELECTIVE HYDROGENATION OF CROTONALDEHYDE

Polymer-stabilized platinum/ruthenium bimetallic colloids （Pt/Ru） were synthesized by polyol reduction with microwave irradiation and characterized by TEM and XPS. The colloidal nanoparticles have small and narrow size distributions. Catalytic performance of the Pt/Ru colloidal catalysts was investigated on the selective hydrogenation of crontonaldehyde （CRAL）. A suitable amount of the added metal ions and base can improve the selectivity of CRAL to crotylalcohol （CROL） remarkably. The catalytic activity and the selectivity are dependent on the compositions of bimetallic colloids. Thereinto, PVP-stabilized 9Pt/1Ru colloid with a molar ratio of metals Pt：Ru = 9：1 shows the highest catalytic selectivity 77.3% to CROL at 333 K under 4.0 MPa of hydrogen.

Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater(CMW)on biological acidification.To reveal the inhibitory effect of wastewater to the anaerobic granular sludge(AnGS),variations of the specific acidogenic activity(SAA)and activities of key enzymes were investigated.The results indicated that the dosage of CMW causing a 50%effect concentration(EC50)on the activity of total volatile fatty acids(TVFA)production was 380 mg COD/g VSS.The inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal,and their inhibitory degrees on individual VFA productions were acetic acid(Ac)>n-butyric acid(n-Bu),which could correspond to the variations in the activities of acetate kinase(AK)and butyrate kinase(BK).Furthermore,the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant,and the contribution of the relative toxicity to CMW was 77.27%.Additionally,the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and(E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of aldehyde.Nevertheless,the removal of ethyl sorbate was primarily based on adsorption.In conclusion,biological acidification has a limited ability to treatment CMW,therefore,a further pretreatment technology should be used to remove the main toxicant of wastewater.

Effect or long-term crotonaldehyde exposure on heart damage in male rats

Objective To observe the effect of long term crotonaldehyde exposure on heart damage in male rats,and to explore the possible mechanism of toxic action.Methods 24 specific pathogen free healthy male wistar rats were randomly divided into 4 groups with 6 rats in each group.Rats were treated with 8.5,4.5,2.5 and 0.0 mg/kg body weight crotonaldehyde by gavage,once a day for consecutive 150 days.After the last treatment,they were anesthetized and blood samples were collected by cardiac puncture.The heart was rapidly separated after cervical dislocation.The cardiac organ coefficient was calculated and the histopathology changes in heart were observed by HE staining.At the same time,the activities of creatine kinase(CK),lactate dehydrogenase-L(LDH-L)in serum were determined by automatic biochemical analyzer.Moreover,the levels of cardiac troponin(cTnT),Angiotensin Ⅱ(Ang Ⅱ),Brain natriuretic peptide(BNP),Aldosterone(ALD)and interleukin(IL)-6,8,1β,interferon(IFN)-γ and tumor necrosis factor(TNF)-α in heart were determined by enzyme linked immunosorbent assay.Results At the 90 d,120 d,and 150 d exposure,compared with the control group,the body weight gain in 4.5 and 8.5 mg/kg groups were decreased.Moreover,the heart weight in 4.5 and 8.5 mg/kg groups,and heart coefficient in 8.5 mg/kg group were decreased(P<0.05).With the increasing dosage of crotonaldehyde,the degree of pathological changes in the heart of exposed rats were aggravated.The major pathological changes of heart in 4.5 and 8.5 mg/kg groups could be summarized as lymphocyte infiltration,abnormal cardiac muscle fiber arrangements,necrosis and fibrous connective tissue hyperplasia.Compared with the control group,the serum CK activity in 4.5 mg/kg group,CK and LDH-L activitivies in 8.5 mg/kg group were increased(P<0.05);Compared with the control group,the levels of ALD and ANGII in the heart of 4.5 and 8.5 mg/kg groups were increased,BNP level were decreased,and cTNT level in 8.5 mg/kg group were increased(P<0.05).Compared with the control group,the levels of IL-1β、IL-6、IL-8 in 4.5 mg/kg group and IL-1β、 IL-6、IL-8、TNF-α、IFN-γ in 8.5 mg/kg group were increased(P<0.05).Conclusion Crotonaldehyde could up-regulate cardiac inflammatory cytokines and alter the balance of angiotensin-aldosterone-brain natriuretic peptide caused heart damage.

Rh/ZnO-Al_2O_3催化剂用于巴豆醛选择性加氢(英文)

Gas phase hydrogenation of crotonaldehyde was performed over 1 wt% Rh/ZnO-Al2O3 catalysts with various Zn/Rh atomic ratios. Monometallic Rh/Al2O3 was also prepared for comparison. The samples were prepared by the successive impregnation of Al2O3 with chlo-ride precursors of zinc and rhodium. The solids have been characterized by H2 chemisorption,temperature-programmed reduction,scanning electron microscopy,and cyclohexane dehydrogenation. Their catalytic behaviour in the gas phase crotonaldehyde hydrogenation reaction after reduction treatment in flowing hydrogen at 723 K was investigated. The relationship between catalytic activity,selectivity for crotyl alcohol,and physicochemical properties of the catalysts was examined. Results obtained showed that the presence of Zn clearly promotes the hydrogenation of the carbonyl bond. The catalyst with Zn/Rh atomic ratio of 5 displayed good catalytic stability and the highest selectivity for crotyl alcohol(70%) along with alloy formation.

Identification and mechanism of formation of certain mutagenic components in the volatile condensates from oxidized and heated edible oils

Edible oils-rapeseed oil, soybean oil and peanut oil are heated in air at 270-280 ℃respectively. The volatile condensates are collected and analyzed by means of GC/MS. Eithercrotonaldehyde or 2-methylacrolein is found respectively in the condensates of rapeseed oil andsoybean oil. Neither crotonaldehyde nor 2-methylacrolein is found in the condensates of peanut oil.Mechanism of formation of crotonaldehyde is discussed.

Effect of impregnation strategy on catalytic hydrogenation behavior of PtCo catalysts supported on La2O2CO3 nanorods

Small Pt and Pt-Co nanoparticles（NPs） stabilized on La2 O2 CO3 nanorods（LOC） were prepared by wet impregnation method,and probed in liquid-phase chemoselective hydrogenation of crotonaldehyde（CRAL） to crotyl alcohol（CROL）.It is found that incorporation of Co atoms into Pt catalyst significantly improves the hydrogenation activity and desired selectivity to CROL as it destroys the Pt-lanthanum interfaces and results into the formation of Pt-Co particles.In addition,a close examination of catalyst surface and reactive performance suggests that the impregnation sequence of Pt and Co exerts great influence on the physicochemical property and the catalytic hydrogenation behavior of PtCo/LOC catalysts.As a result of the interaction between Pt and Co species,high alloying degree of Pt-Co NPs is obtained in the co-impregnated catalyst（Pt-Co/LOC）,thus achieving the highest hydrogenation activity.The selective deposit of Co atoms onto the low-coordinated Pt sites leads to the smallest metal particle size and high dispersion of Pt-Co NPs over the Pt/Co/LOC,giving rise to the highest selectivity and yield to CROL.