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1.
Prostaglandin congeners wherein the 15-hydroxy group is moved to the C16, C17, or C20 position or is replaced by a hydroxymethyl group were prepared the 1,4-addition of a lithium trialkyl- -alkenyl alanate to an appropriate cyclopentenone. Several of the 16-hydroxy derivatives showed significant activity as constrictors of the isolated gerbil colon and in bronchodilator and anti-secretory assays.  相似文献   

2.
Prostaglandin congeners wherein the 15-hydroxy group is moved to the C16, C17, or C20 position or is replaced by a hydroxymethyl group were prepared via the 1,4-addition of a lithium trialkyl-trans-alkenyl alanate to an appropriate cyclopentenone. Several of the 16-hydroxy derivatives showed significant activity as constrictors of the isolated gerbil colon and in bronchodilator and anti-secretory assays.  相似文献   

3.
Prostaglandin congeners wherein the 15-hydroxy group is moved to the C16, C17, or C20 position or is replaced by a hydroxymethyl group were prepared via the 1, 4-addition of a lithium trialkyl-trans-alkenyl alanate to an appropriate cyclopentenone. Several of the 16-hydroxy derivatives showed significant activity as constrictors of the isolated gerbil colon and in bronchodilator and anti-secretory assays.  相似文献   

4.
The iturinic antibiotics, which contain long chain β-amino acids, are produced by Bacillus subtilis. Screening these strains for the presence of a possible precursor of the iturinic antibiotics, we isolated a lipopeptide containing β-hydroxy fatty acids. The structure of this compound was studied and it appears to be identical or structurally very similar to surfactin. The carbon chain of its β-hydroxy fatty acids was n C16, iso C16, iso C15 or anteiso C15. The percentages of each β-hydroxy fatty acids varied according to the strain producing iturinic antibiotics and were influenced by addition of branched-chain α-amino acids to the culture medium. These results demonstrate for the first time that iso C14 β-hydroxy fatty acid is a constituent present in such a surfactin like lipopeptide. Besides, the presence of radioactive β-hydroxy fatty acids in the phospholipids when the strains were grown in the presence of sodium [14C]acetate seems also characterize the different strains producing iturinic antibiotics.  相似文献   

5.
Summary Direct and maternal genetic effects were evaluated for maturing patterns of body weight in mice using a crossfostering design. Crossfostering was performed in one group using dams from populations selected for rapid growth rate (M16 and H6) and their reciprocal F1. crosses. A second crossfostering group consisted of dams from the respective control populations (ICR and C2) and their reciprocal F1. 's. Population differences were partitioned into direct and maternal effects due to genetic origin, correlated selection responses, heterosis and cytoplasmic or sex-linked effects. Degree of maturity was calculated at birth, 12, 21, 31 and 42 days of age by dividing body weight at each age by 63-day weight. Absolute and relative maturing rates were calculated in adjacent age intervals between birth and 63 days. Genetic origin effects (ICR vs. C2; M16 vs. H6) were significant for many maturity traits, with average direct being more important than average maternal genetic effects. In general, correlated responses to selection for maturity traits were larger in the M16 population (M16 vs. ICR) than in the H6 population (H6 vs. C2) and correlated responses in average direct effects were larger than average maternal effects. Positive correlated responses in average direct effects were found for relative maturing rates at all ages and for absolute maturing rates from 31 to 63 days. Apparent correlated responses in degree of maturity were negative for M16 and H6. However, further analysis suggested that the correlated response for degree of maturity in H6 may be positive at later ages and negative at earlier ages. Direct and maternal heterosis for degree of maturity was positive in the selected and control crosses. Absolute and relative maturing rates showed positive heterosis initially, followed by negative heterosis. Reciprocal differences due to the cytoplasm or sex-linkage were not important for patterns of maturity.Paper No. 5244 the Journal Series of the North Carolina Agricultural Experiment Station, Ealeigh, Animal Research Institute Contribution No. 683 and Agricultural University at Wageningen Contribution No. 654–490–12On leave from the Animal Research Institute, Agriculture Canada at Ottawa, OntarioOn leave from the Department of Animal Husbandry, Agricultural University at Wagenitgen, the Netherlands  相似文献   

6.
ABSTRACT. A glycosphingolipid fraction from Trypanosoma mega was isolated after acetylation and was further purified on a silicic acid column. Final purification was by preparative thin-layer chromatography. The carbohydrate components of the glycolipid were fucose and galactose in approximately equimolar amounts. The neutral glycolipid of T. mega has a sphingosine base composition that consists of sphingosine and traces of dihydrosphingosine. Fatty acids forming amide groups with the sphingosine bases were analyzed by gas-liquid chromatography-mass spectrometry and are a mixture of normal and α-hydroxy fatty acids. Normal C16:0, C18:0, and 2-hydroxy C18:0 are the predominant fatty acids.  相似文献   

7.
Abstract

The syntheses of 6-(4) and 7-p-chlorphenyl-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-lumazine (6), was well as the debenzoylation to the corresponding free nucleosides 5 and 7, were improved. Thiation of 4 and 6 by P4S10 led in excellent yields to 4-thiolumazine nucleosides (8, 10) which could be deblocked to 9 and 11 and converted on treatment with ammonia into the isopterin-N-1- ribofuranosides 13 and 14. 2,2′-Anhydro-nucleoside formation worked well with 5 and 7 respectively to give 15 and 16, which formed on acid hydrolysis the 6- and 7-substituted 1-β-D-arabinofuranosyl-lumazines 18 and 19. The new nucleosides have been characterized by UV and 1H-NMR spectra.  相似文献   

8.
Incubation of peripheral blood leukocytes with arachidonic acid (and ionophore A23187) led to the formation of leukotriene B4, Δ6-trans-leukotriene B4, Δ6-trans-12-epi-leukotriene B4, 5-hydroxy-icosatetraenoic acid, 12-hydroxy-icosatetraenoic acid and of 5S,12S-dihydroxy-6,8,10,14-(E,Z,E,Z)-icosatetraenoic acid (5S,12S-DiHETE). Incubation of leukocytes with leukotriene A4 resulted in the formation of leukotriene B4 and of its two Δ6-trans-isomers but not of the 5S,12S-DiHETE. 18O2 labeling experiments have shown that the hydroxyl groups at C5 and C12 in the 5S,12S-DiHETE are derived from molecular oxygen. The tetraacetylenic analog of arachidonic acid was found to be a potent inhibitor of the formation of the 5S,12S-DiHETE whereas it potentiated the synthesis of the 5-hydroxy acid and of leukotriene B4. Addition of the 12-hydroxy-icosatetraenoic acid to leukocytes, or of the 5-hydroxy-icosatetraenoic acid to a suspension of platelets caused the formation of the 5S,12S-DiHETE. It is concluded that the 5S,12S-DiHETE is not derived from leukotriene A4 but is a product of the successive reactions of arachidonic acid with two lipoxygenases of different positional specificities.  相似文献   

9.
The monocarboxylic fatty acids and hydroxy fatty acids of three species of freshwater microalgae—Vischeria punctata Vischer, Vischeria helvetica (Vischer et Pascher) Taylor, and Eustigmatos vischeri (Hulbert) Taylor, all from the class Eustigmatophyceae— were examined. Each species displayed a very similar distribution of fatty acids, the most abundant of which were 20:5n-3, 16:0, and 16:1n-7; C18 polyunsaturated fatty acids were minor components. These fatty acid distributions closely resemble those found in marine eustigmatophytes but are quite distinct from those found in most other algal classes. These microalgae also contain long-chain saturated and unsaturated monohydroxy fatty acids. Two distinct types of hydroxy fatty acids were found: a series of saturated α-hydroxy acids ranging from C24 to C30 with a shorter series of monounsaturated α-hydroxy acids ranging from C26 to C30 together with a series of saturated β-hydroxy acids ranging from C26 to C30. The latter have not previously been reported in either marine or freshwater microalgae, although C30 to C34 midchain (ω-18)-hydroxy fatty acids have been identified in hydrolyzed extracts from marine eustigmatophytes of the genus Nannochloropsis, and C22 to C26 saturated and monounsaturated α-hydroxy fatty acids have been found in three marine chlorophytes. These findings have provided a more complete picture of the lipid distributions within this little studied group of microalgae as well as a range of unusual compounds that might prove useful chemotaxonomic markers. The functions of the hydroxy fatty acids are not known, but a link to the formation of the lipid precursors of highly aliphatic biopolymers is suggested.  相似文献   

10.
The metabolism of several ring C and D-functionalized ent-kaur-16-en-19-oic acids by cultures of Gibberella fujikuroi, mutant B1-41a, to the corresponding derivatives of the normal fungal gibberellins (GAs) and ent-kaurenoids is described. A range of 12α- and 12β-hydroxyGAs and ent-kaurenoids are characterized by their mass spectra and GC Kovats retention indices. The mass spectral and GC data are used to identify the 12α-hydroxy derivatives of GA12, GA14, GA37 and GA4 (GA58), and of the 12β-hydroxy derivatives of ent-7α-hydroxy- and ent-6α, 7α-dihydroxykaurenoic acids, in seeds of Cucurbita maxima. Similarly the metabolites of GA9, formed in seeds of Pisum sativum and cultures of G.fujikuroi, mutant B1-41a, are identified as 12α-hydroxyGA9. ent-11β-Hydroxy- and ent-11-oxo-kaurenoic acids are metabolized by the fungus to the corresponding 11-oxygenated derivatives of the normal fungal ent-kaurenoids and some C20-GAs; no 11-oxygenated C19-GAs are formed. Grandiflorenic acid, 11β-hydroxygrandiflorenic acid, attractyligen and ent-15β-hydroxykaurenoic acid are metabolized to unidentified products.  相似文献   

11.
G-matrix FT projection NMR spectroscopy was employed for resonance assignment of the 79-residue subunit c of the Escherichia coli F1F0 ATP synthase embedded in micelles formed by lyso palmitoyl phosphatidyl glycerol (LPPG). Five GFT NMR experiments, that is, (3,2)D HNNCO, L-(4,3)D HNNC αβ C α, L-(4,3)D HNN(CO)C αβ C α, (4,2)D HACA(CO)NHN and (4,3)D HCCH, were acquired along with simultaneous 3D 15N, 13Caliphatic, 13Caromatic-resolved [1H,1H]-NOESY with a total measurement time of ∼43 h. Data analysis resulted in sequence specific assignments for all routinely measured backbone and 13Cβ shifts, and for 97% of the side chain shifts. Moreover, the use of two G2FT NMR experiments, that is, (5,3)D HN{N,CO}{C αβ C α} and (5,3)D {C αβ C α}{CON}HN, was explored to break the very high chemical shift degeneracy typically encountered for membrane proteins. It is shown that the 4D and 5D spectral information obtained rapidly from GFT and G2FT NMR experiments enables one to efficiently obtain (nearly) complete resonance assignments of membrane proteins. Qi Zhang, Hanudatta S. Atreya, Douglas E. Kamen, Mark E. Girvin and Thomas Szyperski—New York Consortium on Membrane Protein Structure.  相似文献   

12.
The structure and composition of the aliphatic monomers of the polymeric material deposited during wound-healing of tomato fruit, bean pods, and Jade leaves were examined. After removing the cuticle-containing layer of tissue, the wounds were healed for 14 days and the resulting surface layer was excised, lyophilized, solvent-extracted, and depolymerized by hydrogenolysis with LiAlH4 or transesterified with BF3 in methanol. The products obtained by the chemical depolymerization were subjected to thin layer chromatography and combined gas chromatography and mass spectrometry. The major aliphatic components isolated from the hydrogenolysate of the wound polymer produced by tomato fruit were hexadecane-1,16-diol and octadec-9-ene-1,18-diol, which were shown to be derived from a 1:1 mixture of ω-hydroxy and dicarboxylic acids of the appropriate chain length by LiAlH4 reduction. Also identified in the wound polymer were long chain (>C20) fatty acids and alcohols. This monomer composition is typical of suberin polymers and is in sharp contrast with that of the cutin of tomato fruit which contains dihydroxy C16 acid as the major aliphatic component. The hydrogenolysis of the wound material from bean pods gave octadecene-1,18-diol as the major aliphatic component, and smaller amounts of hexadecane-1,16-diol and long chain alcohols. Similar treatment of the normal cuticular tissue of these pods gave hexadecane triol, as well as C16 and C18 alcohols. Hydrogenolysis of wound material from the Jade leaves gave octadecene-1,18-diol, C16 and C22 diols, as well as alcohols from C16 to C26, whereas similar treatment of the cutin-containing tissue from these leaves gave C16 triol as the major aliphatic component. Thus, the major aliphatic monomers of the polymeric material deposited during the wound-healing of bean pods and Jade leaves are very similar to those of suberin, although the natural protective polymer of these tissues is cutin. From these results, it is concluded that suberization is a fundamental process involved in wound-healing in plants, irrespective of the chemical nature of the natural protective polymer of the tissue.  相似文献   

13.
Cutin and suberin polymers from various anatomical regions of grapefruit were analyzed chemically and ultrastructurally. The leaf, fruit peel and juice-sac showed an amorphous cuticular layer. The cutin in the leaf was composed of 10,16-dihydroxy C16 acid and its positional isomers as the major monomers whereas 16-hydroxy-10-oxo C16 acid was a major component in the fruit peel. Juice-sac cutin, on the other hand, contained the dihydroxy C16 acids, hydroxyoxo C16 acids, hydroxyepoxy C18 acids and trihydroxy C18 acids. Ultrastructural examination of the inner seed coat showed that an amorphous cuticular layer encircled the entire seed except in the chalazal region which showed several layers of cells with lamellar suberin structure throughout the cell walls. Consistent with the ultrastructural assignment, the compositions of the aliphatic components of the polymers from the chalazal region and the non-chalazal region indicated the presence of suberin and cutin, respectively. The aliphatic portion of the polymer from the chalazal region of the inner seed coat contained C16, C18:1, C22 and C24 -hydroxy acids (46% combined total) and the corresponding dicarboxylic acids (43%) as the major components. -Hydroxy-9,10-epoxy C18 acids and 9,10,18-trihydroxy C18 acids were the major components (77%) of the polymer from the non-chalazal portion of the inner seed coat. The main portion and the chalazal region of the inner seed coat yielded 17 and 342 g/cm2 of aliphatic monomers, respectively, and the diffusion resistance of these two portions of the inner seed coat were 62 and 192 sec/cm, respectively. The inner seed coat was shown to be the major moisture diffusion barrier influencing imbibition and germination.Scientific Paper No. 5649, Project 2001, College of Agriculture Research Center, Washington State University, Pullman, Washington 99164  相似文献   

14.
Leaf wax of a glaucous variety of Poa ampla contains hydrocarbons (5%, C23–C35), esters (9%, C36–C56), free acids (3%, C16–C34), free alcohols (6%, mainly C26); hentriacontane-14,16-dione (14%), 5-oxohentriacontane-14,16-dione (1%); hydroxy β-diketones (56%) and unidentified material (6%). The hydroxy β-diketones, which are more abundant in this wax than in others, were shown by 13C NMR to consist of 4-hydroxy (15%), 5-hydroxy (70%) and 6-hydroxy (15%) hentriacontane-14,16-diones.  相似文献   

15.
Summary Hydrogen photoproduction has been achieved by coupling free or immobilized hydrogenases from Desulfovibrio species to illuminated chloroplasts through different electron mediators. Whereas D. gigas flavodoxin or ferredoxin I cannot directly mediate the electron flux from chloroplasts to hydrogenase, the addition of these mediators considerably enhances the H2 photoproduction of a system including cytochrome C3. These immobilized hydrogenases exhibit good stability under working conditions and can be re-used.  相似文献   

16.
Epicuticular waxes from whole plants of Agropyron dasystachyum var. psammophylum, A. riparium and A. elongatum contain hydrocarbons (5–8 %), long chain esters (12–15%) and free acids (2–5%). The major esters are C34C56 esters derived from C16C30 acids and alcohols (1-hexacosanol is the major alcohol) but C31, C33 and C35 esters (3–11%) are also present. The latter esters are C18 and C20 acid esters of C13 and C15 2-alkanols. A. dasystachyum wax contains 2% free alcohols, that of A. riparium contains 17% and that of A. elongatum 11% (1-hexacosanol is the major alcohol in each). Diesters (2%), C8C12 diols esterified by (E)-2-alkenoic acids, are present in A. riparium wax. Hentriacontane-14,16-dione is present: 29% in A. dasystachyum wax and 32% in A. riparium wax, but only 5% in A. elongatum wax. 25-Oxohentriacontane-14,16-dione forms 14% of A. dasystachyum wax and 27% of A. elongatum wax but the oxo β-diketones of A. riparium wax (5%) consist of both 10-oxo- and 25-oxohentriacontane-14,16-diones in the ratio 4:1. Hydroxy β-diketones of the waxes are 25- and 26-hydroxyhentriacontane-14,16-diones; in A. dasystachyum (20%) the ratio is 3:1, in A. elongatum (20%) the ratio is 9:1 but in A. riparium (5%) it is ca 1:2. The configuration of the hydroxyl group in the 26-hydroxy β-diketone is opposite to that in the 25-hydroxy derivative. The unusual composition of the oxygenated β-diketones of A. riparium confirms that this species should be regarded as separate from A. dasystachyum. Wax from A. elongatum also contains 4-hydroxy-25-oxohentriacontane-14,16-dione (4%) and an unusual oxo-β-ketol, 18-hydroxy-7,16-hentriacontanedione (2%), both these components are probably derived biosynthetically from the 25-oxo β-diketone which is the major component of this wax. Syntheses of racemic 18-hydroxy-7,16-hentriacontanedione and of a model β-ketol, 12-hydroxy-10-pentacosanone, are described.  相似文献   

17.
Abstract

The synthesis of pyrazolo[3,4-d]pyrimidine 2′-deoxyribo-nucleosides with various substituents at C-4 and C-6 (1 4) is described employing either liquid-liquid or solid-liquid phase-transfer glycosylation. From 1a (Z8C7Ad) and 2b (Z8C7Gd) the phosphoramidites 12a, b and 15a, b were synthesized. They were used in automated solid-phase synthesis resulting in the oligonucleotides 16 - 25. Deoxygenation (3′-OH) of 1a and 2b yielded pyrazolo[3,4-d]-pyrimidine 2′,3′-dideoxynucleosides isosteric to ddA, ddG, and ddI.  相似文献   

18.
Diatoms are one of the largest groups of primary producers in the oceans, yet despite their environmental importance little is known about their plastidial lipid biochemistry. It has been previously reported that Skeletonema species contain primarily C16/C16 and C20/C16 forms of mono‐ and digalactosyldiacylglycerol (MGDG and DGDG, respectively). Likewise, it was also reported that Phaeodactylum tricornutum contains primarily C16/C16 and C20/C20 forms of MGDG and DGDG. We seek to relate their studies to other diatoms, both in the centrics and pennates, with particular focus on the marennine‐producing pennate diatom, Haslea ostrearia. To this end, the composition and positional distribution of fatty acids of MGDG and DGDG were examined using positive‐ion electrospray ionization/mass spectrometry (ESI/MS). Two centric diatoms, Skeletonema marinoi and Thalassiosira weissflogii, and the pennate diatom, P. tricornutum, contained primarily C20/C16 (sn‐1/sn‐2) and C18/C16 forms of MGDG and DGDG. The other pennate diatoms, H. ostrearia and Navicula perminuta, contained primarily C18/C16 or C18/C18 forms of MGDG and DGDG, indicating a previously unrecognized fatty acid diversity in diatom MGDG and DGDG.  相似文献   

19.
Inhibition of dark CO2 fixation by susceptible corn leaves was used to compare the relative toxicity of synthetic analogs with that of the host-specific phytotoxin produced by the fungal corn pathogen, Helminthosporium maydis, race T. Analogs with C15, C25, or C26 chain lengths and 1,5-dioxo-3-hydroxy functions were only slightly less toxic (2–6 × 10?7M) than native T toxin (C35–C45 chain lengths) or its individual components (3 × 10?8M). Like native toxin, analogs were host-specific in that they did not inhibit dark CO2 fixation in leaf tissue of resistant corn at concentrations 102–103 times greater than those effective with susceptible corn. These findings support the structures previously proposed for native T toxin.  相似文献   

20.
Some ω-chain phenyl- and 16-phenoxy- analogues of (±)-11-deoxyprostaglandin F have been synthesized and evaluated for anti-fertility activity in the hamster. 11-Deoxy-16-phenoxy-17,18,19,20-tetranor-PGF was the most active member of the series with an ED50 equal to that of PGF. 11-Deoxy-17-phenyl-18,19,20-trinor-PGF, which was one third as active as PGF, was more potent than the corresponding 16- and 18-phenyl compounds. Aryl ring substitution was found to lower activity, except that with the 16-phenyl compound, p-bromo and m-trifluoromethyl substitution increased the potency.The antifertility activity of the phenoxy compounds, which were poor substrates for 15-hydroxyprostaglandin dehydrogenase, was shown to correlate well with the binding affinity for the bovine corpus luteum PGF receptor. Some quantitative structure-activity data supporting this finding are presented.  相似文献   

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