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1.
The hydrocarbons (3Z,6Z,9Z)-3,6,9-octadecatriene (3Z,6Z,9Z-18:H) and (3Z,6Z,9Z)-3,6,9-nonadecatriene (3Z,6Z,9Z-19:H) constitute the pheromone of the winter moth, Erannis bajaria. These compounds belong to a large group of lepidopteran pheromones which consist of unsaturated hydrocarbons and their corresponding
oxygenated derivatives. The biosynthesis of such hydrocarbons with an odd number of carbons in the chain is well understood.
In contrast, knowledge about the biosynthesis of even numbered derivatives is lacking. We investigated the biosynthesis of
3Z,6Z,9Z-18:H by applying deuterium-labeled precursors to females of E. bajaria followed by gas chromatography–mass spectrometry analysis of extracts of the pheromone gland. A mixture of deuterium-labeled
[17,17,18,18-2H4]-3Z,6Z,9Z-18:H and the unlabeled 3Z,6Z,9Z-18:H was obtained after topical application and injection of (10Z,13Z,16Z)-[2,2,3,3-2H4]-10,13,16-nonadecatrienoic acid ([2,2,3,3-2H4]-10Z,13Z,16Z-19:acid) or (11Z,14Z,17Z)-[3,3,4,4-2H4]-11,14,17-icosatrienoic acid ([3,3,4,4-2H4]-11Z,14Z,17Z-20:acid). These results are consistent with a biosynthetic pathway that starts with α-linolenic acid (9Z,12Z,15Z-18:acid). Chain elongation leads to 11Z,14Z,17Z-20:acid, which is shortened by α-oxidation as the key step to yield 10Z,13Z,16Z-19:acid. This acid can be finally reduced to an aldehyde and decarbonylated or decarboxylated to furnish the pheromone component
3Z,6Z,9Z-18:H. A similar transformation of 11Z,14Z,17Z-20:acid yields the second pheromone component, 3Z,6Z,9Z-19:H. 相似文献
2.
A new version of the STRUCTON-1.2 computer program (2009) has been presented. The program combines the algorithm for calculating
real distributions of Q
n
structons in binary silicate melts (with allowance made for their disproportionation) and the statistical simulation of molecular-mass
distributions of polymerized ions at different temperatures. This model has been used to perform test calculations for two
melts in the Na2O-SiO2 system (Na6Si2O7, Na6Si3O9). The results of the calculations have made it possible to trace variations in the set and concentrations of chain and ring
silicon-oxygen complexes with a decrease in the temperature in the order: stochastic molecular-mass → distribution molecular-mass
distribution at T = 2000 K → molecular-mass distribution at the liquidus temperature. The main result of these calculations is that the dominant
species of silicon-oxygen anions at the liquidus temperatures (in contrast to the stochastic distributions) exactly correspond
to the stoichiometry of the initial melts: the Si2O76− chain anions and (Si
n
O3n
)3n− ring complexes are dominant in the Na6Si2O7 and Na6Si3O9 melts, respectively. It has been established that, with a decrease in the temperature, the average size of polymer complexes
varies weakly in the Na6Si2O7 melt but increases by a factor of approximately 1.5 in the metasilicate system. 相似文献
3.
Two antibacterial and xanthine oxidase inhibitory cerebrosides, one of which is chemically new, were characterized from the
chloroform-methanol (1∶1) extract of Fusarium sp. IFB-121, an endophytic fungus in Quercus variabilis. By means of chemical and spectral methods [IR, electrospray ionization MS (ESI-MS), tandem ESI-MS, 1H and 13C NMR, distortionless enhancement by polarization transfer, COSY, heteronuclear multiple-quantum coherence, heteronuclear
multiple-bond correlation, and 2-D nuclear Overhauser effect correlation spectroscopy], the structure of the new metabolite
named fusaruside was established as (2S,2′R,3R,3′E,4E,8E,10E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8,10-sphingatrienine, and the structure of the other was identified as
(2S,2′R,3R,3′E,4E,8E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine. Both new and known cerebrosides, although inactive to
Trichophyton rubrum and Candida albicans, showed strong antibacterial activities against Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens, with their minimum inhibitory concentrations being 3.9, 3.9, and 1.9 μg/mL, and 7.8, 3.9, and 7.8 μg/mL, respectively. Furthermore,
both metabolites were inhibitory to xanthine oxidase, with the IC50 value of fusaruside being 43.8±3.6 μM and the known cerebroside being 55.5±1.8 μM. 相似文献
4.
As a continuation of our study on plants of the Sapindaceae, the chemical composition of the oil extracted from seeds of Allophylus natalensis (Sonder) De Winter and of A. dregeanus (Sonder) De Winter has been investigated. The oil from both species contained approximately equal amounts of TAG and type
I cyanolipids (CL), 1-cyano-2-hydroxymethylprop-2-en-1-oldiesters, with minor amounts of type III CL, 1-cyano-2-hydroxymethylprop-1-en-3-ol-diesters.
Structural investigation of the oil components was accomplished by chemical, chromatographic (TLC, CC, GC, and GC-MS), and
spectroscopic (IR, NMR) means. GC and GC-MS analysis showed that C20 FA were dominant in the CL components of the oil from the two species (44–80% vs. 21–26% in TAG), with cis-11-eicosenoic acid (36–46%) and cis 13-eicosenoic acid (paullinic acid, 23–37%) as the major esterified fatty acyl chains in A. natalensis and A. dregeanus, respectively. cis-Vaccenic acid was particularly abundant (11–31%) in the CL from A. dregeanus, whereas eicosanoic acid (10–22%) was also a major component of CL in both species. 相似文献
5.
Elena Pastor-Cavada Rocio Juan Julio E. Pastor Manuel Alaiz Javier Vioque 《Journal of the American Oil Chemists' Society》2009,86(4):329-335
The fatty acid composition of the seed oil of 19 wild legume species from southern Spain was analyzed by gas chromatography.
The main seed oil fatty acids ranged from C14:0 to C20:0. Among unsaturated fatty acids, the most abundant were linoleic, oleic and linolenic acids, except for Lathyrus angulatus, L. aphaca, L. clymenum, L. sphaericus and L. nigricans where C18:3 contents were higher than C18:1 contents. Palmitic acid was the most abundant saturated acid in studied species, ranging from 11.6% in Lathyrus sativus to 19.3% in Lens nigricans. All studied species showed higher amounts of total unsaturated fatty acids than saturated ones. Among studied species, the
ω6/ω3 ratio was variable, ranging from 2.0% in L. nigricans to 13.8% in L. sativus, there being eight species in which the ω6/ω3 ratio was below 5. The fatty acids observed in these plants supports the use
of these plants as a source of important dietary lipids. 相似文献
6.
The physical parameters, which describe the relaxation phenomena occurring in both the bulk and contact regions of the systems
under investigation, have been calculated using experimental curves of isothermal relaxation of polarization current in thin
films of modified (As2Se3)100 − x
Bi
x
. The relation between the change in the internal structure of the studied materials and the processes of charge transfer
and charge accumulation has been revealed. The results obtained have been discussed with invoking the relay-race mechanism
of charge transfer. 相似文献
7.
J.-F. Butaud P. Raharivelomanana J.-P. Bianchini E. M. Gaydou 《Journal of the American Oil Chemists' Society》2008,85(4):353-356
The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry
(GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The
content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic
acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species
belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content. 相似文献
8.
The pinewood nematode (PWN), Bursaphelenchus xylophilus, the most important invasive species in pine forests of Asia, is transported to new pine hosts by beetles of the genus Monochamus. Third-stage dispersal juveniles (JIII) aggregate in pupal chambers around the vector as it matures. We demonstrated that the ratio of three terpenes (α-pinene,
β-pinene, and longifolene at 1:2.7:1.1) released by larval Monochamus alternatus strongly attract JIII, whereas the different ratio (1:0.1:0.01) of these three terpenes found in healthy xylem of Pinus massoniana attracts only the propagative stage (Jn) of the nematode. We suggest that the volatiles produced by the host plants could be the basis of a chemoecological relationship
between plant parasitic nematodes and their vector insects. Capture of JIII with terpene-baited trap tubes deployed for 2 hr in the field was demonstrated. This technique may lead to the development
of rapid sampling methodologies for use at either ports-of-entry or in the field. 相似文献
9.
The oxygen exchange between powders of the layered oxides LnBaCuFeO5 + δ (Ln = La, Pr) and the environment and the oxygen nonstoichiometry index δ of these oxides have been investigated using solidelectrolyte
coulometry in the temperature range 20–800°C and at oxygen partial pressures in the range 3–346 Pa. It has been found that
the evolution (absorption) of oxygen by the powdered samples proceeds in two stages and that the transition between the stages
corresponds to a particular value of the degree of filling of the layers with oxygen (δ ≈ 0.25 for Ln = La and δ ≈ 0.125 for Ln = Pr). The conclusion has been drawn from analyzing the results obtained that, in the layers -LnOδ-of the crystal structure of the LnBaCuFeO5 + δ phases, oxygen undergoes a sequential ordering and that, in these layers, oxygen can exist in two forms: ordered and disordered.
The latter form represents weakly bound oxygen which can be easily exchanged between the samples and the environment. 相似文献
10.
Two tunicates (Fudistoma bituminis and Cystodytes violatinctus, family Polycitoridae) were investigated for the FA content of their phospholipids. GC-MS analysis of their methyl esters
and N-acyl pyrrolidides revealed 40 FA in E. bituminis, and 26 in C. violatinctus. In both cases, the most abundant FA were the saturated ones (C10 to C18). Cystodytes violatinctus contained considerable oleic acid (20%). Both E. bituminis and C. violatinctus contained phytanic acid and Δ10-unsaturated FA, which had not previously been found in such organisms. The two tropical tunicates contained only trace amounts
of PUFA, which are usually predominant in this phylum. 相似文献
11.
A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods
as (2S, 3S, 4R, 2′R, 14E)-2-(2′-hydroxydocosanoylamino)-14-octadecene-1,3,4-triol (1), (2S,3S,4R,2′R, 14F)-2-(2′-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2′R,14F)-2-(2′-hydroxytetracosanoylamino)-14-octadecene-1,3,4-triol (3), (2S,3S,4R,2′R,14E)-2-(2′-hydroxypentacosanoylamino)-14-octadecene-1,3,4-triol (4), and (2S,3S,4R,2′R,14E)-2-(2′-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5). 相似文献
12.
Bogdan H. Dana C. John McAdam Brian H. Robinson Jim Simpson Hongsheng Wang 《Journal of Inorganic and Organometallic Polymers and Materials》2007,17(3):547-559
A series of N-allyl, N-ethylmethacrylate and N-phenylmethacrylatenaphthalimide monomers have been prepared with –C=CFc, –C≡CFc and –C≡CSiMe3 substituents at the 4-position of the naphthalimide ring. All have been characterised by elemental analysis and spectroscopy;
the X-ray structure of N-allyl-4-ethenylferrocenylnapththalimide is also reported. Free-radical polymerisation of these monomers gave homopolymers,
random co- and terpolymers with polydispersities ranging from 1.7 to 3.2. Incorporation into a polymer matrix has no effect
on the spectroscopic and electrochemical properties of the naphthalimide or ferrocenyl components. The ferrocenyl polymers
are electrochromic and when oxidised give naphthalimide charge-transfer bands in the NIR; this electrochromism was examined by OTTLE techniques. 相似文献
13.
Nguyen Van Duc Long Ju Weon Lee Thai-Hoang Le Jin-Il Kim Yoon-Mo Koo 《Korean Journal of Chemical Engineering》2011,28(4):1110-1119
In batch chromatography, solvent-gradient operations (SG) produce significant improvement in terms of the enrichment of products
and the separation time and the solvent consumption as compared with isocratic operations. This work studied solvent-gradient
operation in reversed-phase simulated moving bed unit to separate ortho-xylene and para-xylene. In a solvent-gradient mode, different mobile phase compositions lead to a different retention behavior of solutes,
i.e., different adsorption isotherms. Frontal analysis experiments for ortho-xylene and para-xylene were carried out with a reversed-phase column to measure adsorption parameters at several different mobile phase compositions,
such as 45%, 50%, 60%, 75% and 90% acetonitrile. Therefore, the parameters in the retention model for solvent-gradient operation
in the case of reversed-phase chromatography were estimated and applied to the design of an SMB system. A modified design
method for solvent-gradient simulated moving bed chromatography (SG-SMB) was proposed. The robust operating conditions were
obtained within the separation region on (φ
R
, φ
E
) plane (φ
R
and φ
E
are the volumetric content of organic modifier in the raffinate and the extract streams, respectively). The performance results
of isocratic and solvent-gradient SMB were compared. A partial-discard strategy and increasing of the solvent gradient level
were also applied to improve the performance of the SG-SMB. 相似文献
14.
Evidence suggests that minor isomers of conjugated linoleic acid (CLA), such as trans8, cis10 CLA, can elicit unique biological effects of their own. In order to determine the effect of a mixture of t8, c10+c9, t11 CLA isomers on selected aspects of lipid metabolism, 3T3-L1 preadipocytes were differentiated for 8 days in the presence
of 100 μM linoleic acid (LA); t8, c10+c9, t11 CLA; t10, c12+c9, t11 CLA or purified c9, t11 CLA. Whereas supplementation with c9, t11 and t10, c12+c9, t11 CLA resulted in cellular triglyceride (TG) concentrations of 3.4 ± 0.26 and 1.3 ± 0.11 μg TG/μg protein, respectively (P < 0.05), TG accumulation following treatment with CLA mixture t8, c10+c9, t11 was significantly intermediate (2.5 ± 0.22 μg TG/μg protein, P < 0.05) between the two other CLA treatments. However, these effects were not attributable to an alteration of the Δ9 desaturation index. Adiponectin content of adipocytes treated with t8, c10+c9, t11 mixture was similar to the individual isomer c9, t11 CLA, and both the t8, c10+c9, t11 and c9, t11 CLA groups were greater (P < 0.05) than in the t10, c12+c9, t11 CLA group. Overall, these results suggest that t8, c10+c9, t11 CLA mixture affects TG accumulation in 3T3-L1 cells differently from the c9, t11 and t10, c12 isomers. Furthermore, the reductions in TG accumulation occur without adversely affecting the adiponectin content of these
cells. 相似文献
15.
Five cerebrosides (1–5), including three new ones named cortenuamide A (1), cortenuamide B (2), and cortenuamide C (3), were isolated from the fruiting bodies of the basid-iomycete Cortinarius tenuipes. The structures of those compounds were elucidated as (4E,8E)-N-d-2′-hydroxytetracosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (1), (4E,8E)-N-d-2′-hydroxytricosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8 sphingadienine (2), (4E, 8E)-N-d-2′-hydroxydocosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (3), (4E, 8E)-N-d-2′-hydroxyoctadecanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (4), and (4E, 8E)-N-d-2′-hydroxypalmitoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (5) by spectral and chemical methods. 相似文献
16.
Asperamides A (1) and B (2), a sphingolipid and their corresponding glycosphingolipid possessing a hitherto unreported 9-methyl-C20-sphingosine moiety, were characterized from the culture extract of Aspergillus niger EN-13, an endophytic fungus isolated from marine brown alga Colpomenia sinuosa. The structures were elucidated by spectroscopic and chemical methods as (2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (1) and 1-O-β-d-glucopyranosyl-(2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (2). In the antifungal assay, asperamide A (1) displayed moderate activity against Candida albicans. 相似文献
17.
The optimum conditions for synthesizing LiNi1-y
Co
y
O2 (y=0.1, 0.3 and 0.5) by a simplified combustion method, in which the preheating step is omitted, and the electrochemical properties
of these materials were investigated. The optimum condition for synthesizing LiNi0.9Co0.1O2 by the simplified combustion method is calcination at 800 °C for 12 h in air in 3.6 mole ratio of urea to nitrate. The LiNi0.9Co0.1O2 synthesized under these conditions shows the smallest R-factor{(I
006+I
102)/I
101} and the largest I
003/I
104, indicating better hexagonal ordering and less cation mixing, respectively. The LiNi0.7Co0.3O2 synthesized at 800 °C for 12 h in air in 3.6 mole ratio of urea to nitrate has the largest first discharge capacity 156.2 mA h g−1 at 0.5C and shows relatively good cycling performance. This sample shows better hexagonal ordering and less cation mixing
than the other samples. The particle size of the LiNi0.7Co0.3O2 is relatively small and its particles are spherical with uniform particle size. 相似文献
18.
Andrzej Piasecki Sławomir Karczewski Irena Maliszewska 《Journal of surfactants and detergents》2007,10(2):93-101
A homologous series of new surface-active 1,1-bis{[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides were synthesized in the reaction of an appropriate diethyl 2-alkylmalonate with N,N-dimethylamino-1,3-propanediamine followed by oxidation with aqueous hydrogen peroxide. The adsorption isotherms of their
aqueous solutions were measured and evaluated to obtain adsorption parameters: critical micelle concentration (CMC), surface
excess concentration (ΓCMC), equilibrium surface tension at the CMC (γCMC), cross-sectional area of the adsorbed surfactant molecule (A
CMC), efficiency of surface adsorption (pC20), standard free energies of adsorption (ΔG°ads), and micellization (ΔG°CMC). All investigated di-amidoamines and di-N-oxides were practically non-toxic to selected bacteria and yeasts. These compounds are readily biodegradable in the Closed
Bottle Test inoculated with activated sludge. Surface and biological properties showed that this group of N-oxide-type compounds has high surface activity and fulfills requirements for environmental acceptance.
相似文献
Andrzej PiaseckiEmail: |
19.
Ramesh Pratibha Nalini Larysa Khomenkova Olivier Debieu Julien Cardin Christian Dufour Marzia Carrada Fabrice Gourbilleau 《Nanoscale research letters》2012,7(1):124
Microstructural, electrical, and optical properties of undoped and Nd3+-doped SiO
x
/SiN
y
multilayers fabricated by reactive radio frequency magnetron co-sputtering have been investigated with regard to thermal
treatment. This letter demonstrates the advantages of using SiN
y
as the alternating sublayer instead of SiO2. A high density of silicon nanoclusters of the order 1019 nc/cm3 is achieved in the SiO
x
sublayers. Enhanced conductivity, emission, and absorption are attained at low thermal budget, which are promising for photovoltaic
applications. Furthermore, the enhancement of Nd3+ emission in these multilayers in comparison with the SiO
x
/SiO2 counterparts offers promising future photonic applications. 相似文献
20.
Shanyin Yan Wenqiu Chen Xiaojin Yang Chuan Chen Mingfu Huang Zushun Xu Kelvin W. K. Yeung Changfeng Yi 《Polymer Bulletin》2011,66(9):1191-1206
A novel pyridine-containing aromatic diamine monomer, 4-phenyl-2,6-bis[3-(4-aminophenoxy)phenyl]pyridine (m,p-PAPP), was successfully synthesized by a modified Chichibabin reaction of benzaldehyde and a substituted acetophenone, 3-(4-nitrophenoxy)acetophenone
(m,p-NPAP), followed by a reduction of the resulting dinitro compound 4-phenyl-2,6-bis[3-(4-nitrophenoxy)phenyl]pyridine (m,p-PNPP) with Pd/C and hydrazine monohydrate. The aromatic diamine was employed to synthesize a series of pyridine-containing
polyimides (PIs) by polycondensation with various aromatic dianhydrides in N,N-dimethylformamide (DMF) via the conventional two-step method, and further thermal or chemical imidization forming PIs. The
inherent viscosities of the resulting poly(amic acid)s and PIs were 0.59–0.73 and 0.56–0.68 dL/g; most of the PIs obtained
by chemical imidization were readily soluble in common organic solvents such as DMF, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), etc. Meanwhile, strong and flexible PI films were obtained, which had
good thermal stability, with the glass transition temperature (T
g) of 204.5–237.4 °C and the temperature at 10% weight loss of 527.7–552.0 °C in nitrogen atmosphere, as well as outstanding
mechanical properties with tensile strengths of 88.6–90.4 MPa, a tensile moduli of 1.04–1.56 GPa, and elongations at break
of 7.2–8.7%. The PI films also were found to possess low water uptake of 0.89–0.98%. 相似文献