共查询到20条相似文献,搜索用时 31 毫秒
1.
Zur Stereochemie der Propandioldehydrase-Reaktion 总被引:2,自引:0,他引:2
Summary Propanedioldehydrase is shown to convert both (+)-(S)-2-2H-propanediol,3, and (–)-(R)-1-2H2-propanediol,5, to specimens of deuterated propion-aldehyde, for which the (S)-configuration has been established. Thus, in the propanedioldehydrase reaction migration of hydrogen atoms from C–1 to C–2 always occurs with inversion of configuration. 相似文献
2.
P. Ciminiello E. Fattorusso S. Magno A. Mangoni A. Ialenti M. Di Rosa 《Cellular and molecular life sciences : CMLS》1991,47(7):739-743
Summary Three new furan fatty acids, (9Z, 19Z)-3, 6-epoxyhexacosa-3,5,19-tetraenoic acid (1a), (8Z, 11Z, 14Z, 17Z)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (2a), and (8Z, 11Z, 14Z, 17E)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (3a), and a new polyunsaturated fatty acid (5Z, 8Z, 11Z, 14Z, 17E)-eicosa-5,8,11,14,17-pentaenoic acid (6a), present in the spongeDictyonella incisa as the respective steryl esters, have been isolated as methyl esters and their structures have been determined by spectral and chemical analysis. The furan fatty acid esters have shown a high inflammatory activity, which suggests their potential role as feeding deterrents. 相似文献
3.
C. Fuganti D. Ghiringhelli P. Grasselli 《Cellular and molecular life sciences : CMLS》1978,34(3):297-298
Summary (1
R) [1-3H,2H1] 3-Phenylpropanol, the key intermediate in the synthesis of (4
R) [4-3H,2H1] D, L-homoserine and of the (4
S)-isomer, is obtained from (1
S) [1-2H1] 3-phenylpropanol and (1
RS) [1-3H] ethanol upon incubation with yeast alcohol dehydrogenase and NAD+; under similar conditions 2-phenylethanol undergoes very small exchange with [1-2H2] ethanol. 相似文献
4.
Zusammenfassung Durch Zugabe und durch Auswaschen von Mg-Pyrophosphat (0,5 mM) oder Mg-Tripoly-Phosphat (1 mM) konnten (in Abwesenheit von ATP) in glyzerinextrahierten Fasern von fibrillären Insektenmuskeln (Lethocerus maximus) reversible Kontraktionszyklen und Änderungen des Dehnungswiderstandes bewirkt werden.
Supported by Grant No. Ru 154/b of the Deutsche Forschungsgemeinschaft. The excellent technical assistance of Mrs.Helgard Jung is gratefully acknowledged. 相似文献
Supported by Grant No. Ru 154/b of the Deutsche Forschungsgemeinschaft. The excellent technical assistance of Mrs.Helgard Jung is gratefully acknowledged. 相似文献
5.
E. Curio 《Cellular and molecular life sciences : CMLS》1961,17(4):188-189
Summary German Pied Flycatchers (Ficedula hypoleuca hypoleuca) show a mobbing response to the Redbacked Shrike (Lanius collurio) as well as to owls. Spanish Pied Flycatchers (Ficedula hypoleuca iberiae) mob only at the latter. This correlates well with the fact that only nominatehypoleuca occurs together with the shrike, but both subspecies share their habitats with owls.
Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. 相似文献
Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. 相似文献
6.
R. N. Chakravarti 《Cellular and molecular life sciences : CMLS》1947,3(4):149-149
Summary K(CdCl3) has a structure of the E 24-type. In comparison with the isotype (NH4) (CdCl3) only two of the three lattice constants have noticeably different values. They area andb which show a contraction of about 2%, whereas the constantc is about the same for both salts. 相似文献
7.
P. P. Halarnkar G. P. Jackson K. M. Straub D. A. Schooley 《Cellular and molecular life sciences : CMLS》1993,49(11):988-994
We studied time-dependent metabolism of (10R)-[3H] juvenile hormone (JH) III and (10R, 11S)-[3H]JH I injected intoManduca sexta larvae; the hormones are metabolized to polar metabolites, expecially the JH acid-diol, and an unknown. Products were analyzed using a reversed-phase liquid chromatography assay. (10R)-JH III is metabolized much more rapidly than (10R, 11S)-[3H]JH I, whether injected seperately or as a mixture of hormones. The unknown metabolites of JH I and JH III were identified as phosphate conjugates of JH I and JH III diol by tandem mass spectral analysis of isolated samples. The phosphate conjugate of JH I diol is the principle end product of JH I metabolism. 相似文献
8.
Maria C. Shina Annette Müller-Taubenberger Can Ünal Michael Schleicher Michael Steinert Ludwig Eichinger Rolf Müller Rosemarie Blau-Wasser Gernot Glöckner Angelika A. Noegel 《Cellular and molecular life sciences : CMLS》2011,68(2):303-313
Dictyostelium discoideum harbors a short (CRN12) and a long coronin (CRN7) composed of one and two beta-propellers, respectively. They are primarily
present in the cell cortex and cells lacking CRN12 (corA
−) or CRN7 (corB
−) have defects in actin driven processes. We compared the characteristics of a mutant cell line (corA
−
/corB
−) lacking CRN12 and CRN7 with the single mutants focusing on cytokinesis, phagocytosis, chemotaxis and development. Cytokinesis,
uptake of small particles, and developmental defects were not enhanced in the corA
−
/corB
− strain as compared to the single mutants, whereas motility and phagocytosis of yeast particles were more severely impaired.
It appears that although both proteins affect the same processes they do not act in a redundant manner. Rather, they often
act antagonistically, which is in accordance with their proposed roles in the actin cytoskeleton where CRN12 acts in actin
disassembly whereas CRN7 stabilizes actin filaments and protects them from disassembly. 相似文献
9.
T. Yamada K. Kageyama Y. Joh J. Konishi K. Ienaga 《Cellular and molecular life sciences : CMLS》1998,54(2):125-128
2′-O-Methylinosine (1) has been isolated for the first time and shown to be an intrinsic hypotensive principle. Its probable in vivo precursor,
2′-O-methyladenosine (3), showed stronger and even orally potent hypotensive activity. Resistance of the methyladenosine (3) against adenosine deaminase is thought to contribute to its long-lasting activity. The effect of both nucleosides (1 and 3) was not accompanied with any significant change in heart rate, which is often observed with adenosine.
Received 2 October 1997; accepted 28 October 1997 相似文献
10.
B. P. Vaterlaus K. Doebel J. Kiss A. I. Rachlin H. Spiegelberg 《Cellular and molecular life sciences : CMLS》1963,19(8):383-391
Summary The synthesis of the antibiotic novobiocin is described. First the essential carbohydrate, the 3-O-carbamoylnoviose was synthesized fromd-glucose. A number of steps (1–6) led to the 3,5,6-tri-O-benzyl-2-O-methyl-d-galactono--lactone (6) which is characterized by the correct array of carbon atoms inherent to the noviose. Further transformations (7–15) finally yielded the carbohydrate. The problem of glycosidation is discussed in some detail. Glycosidation of a suitable aglycon precursor (18) with 2,3-O-carbonyl--noviosyl-chloride (22) proved possible and led to the isolation of an-glycoside (23) which was further transformed (24–28) into novobiocin.
Chemische Forschungsabteilung der F. Hoffmann-La Roche & Co. AG, Basel.
Vortrag Dr.B. P. Vaterlaus, gehalten an der Gordon Research Conference on Steroids and other Natural Products, 16.–20. Juli 1962, New Hampton, N.H., USA, und vor der Basler Chemischen Gesellschaft, 8. November 1962. Im Auszug:H. Spiegelberg,Synthèse du 3-O-carbamoylnoviose, sucre de la novobiocine, Symposium international de chimie organique, Bruxelles, 15. Juni 1962;J. Kiss,The Synthesis of Noviose and Allied Compounds, Birkbeck College (Univ. London), 23. Oktober 1962. Der vorliegende Aufsatz ist Gegenstand von Detailpublikationen in den Helv. chim. Acta, in Vorbereitung (1963). 相似文献
Chemische Forschungsabteilung der F. Hoffmann-La Roche & Co. AG, Basel.
Vortrag Dr.B. P. Vaterlaus, gehalten an der Gordon Research Conference on Steroids and other Natural Products, 16.–20. Juli 1962, New Hampton, N.H., USA, und vor der Basler Chemischen Gesellschaft, 8. November 1962. Im Auszug:H. Spiegelberg,Synthèse du 3-O-carbamoylnoviose, sucre de la novobiocine, Symposium international de chimie organique, Bruxelles, 15. Juni 1962;J. Kiss,The Synthesis of Noviose and Allied Compounds, Birkbeck College (Univ. London), 23. Oktober 1962. Der vorliegende Aufsatz ist Gegenstand von Detailpublikationen in den Helv. chim. Acta, in Vorbereitung (1963). 相似文献
11.
S. Dolfini A. M. Courgeon L. Tiepolo 《Cellular and molecular life sciences : CMLS》1970,26(9):1020-1021
Riassunto La durata media delle fasi del ciclo cellulare (G1, S e G2) e del tempo di generazione totale (G
T
) in una linea stabilizzata di cellule diDrosophila melanogaster risulta essere rispettivamente di 1.8, 10.0, 7.2 e 18.8 ore. 相似文献
12.
Richard Ashley 《Journal of forecasting》1983,2(3):211-223
A forecasting model for yt based on its relationship to exogenous variables (e.g. x?t) must use x?t, the forecast of x?t. An example is given where commercially available x?t's are sufficiently inaccurate that a univariate model for yt appears preferable. For a variety of types of models inclusion of an exogenous variable x?t is shown to worsen the yt forecasts whenever x?t must itself be forecast by x?t and MSE (x?t) > Var (x?t). Tests with forecasts from a variety of sources indicate that, with a few notable exceptions, MSE (x?t) > Var (x?t) is common for macroeconomic forecasts more than a quarter or two ahead. Thus, either:
- (a) available medium range forecasts for many macroeconomic variables (e.g. the GNP growth rate) are not an improvement over the sample mean (so that such variables are not useful explanatory variables in forecasting models), and/or
- (b) the suboptimization involved in directly replacing x?t by x?t is a luxury that we cannot afford.
13.
Summary The phenylpropylamine fraction ofCatha edulis FORSK. grown in Kenya has been investigated. The major components have been found to be (S)-(–)--aminopropiophenone (1), (+)-norpseudoephedrine (2) and(–)-norephedrine (3). Quantitative ratios of1, 2, 3 in tissues of different age are discussed.
ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft相似文献
14.
K. Yamada 《Cellular and molecular life sciences : CMLS》1964,20(8):444-445
Zusammenfassung In Parenchymzellen der Epithelkörperchen von Affen (Macaca cyclopis) und Wachteln (Coturnix coturnix japonica) lassen sich zwei Typen von Proteingranula histochemisch unterscheiden. Die cytophysiologische Wertung dieser Granula wurde diskutiert. 相似文献
15.
G. Cimino S. de Stefano W. Fenical L. Minale J. J. Sims 《Cellular and molecular life sciences : CMLS》1975,31(11):1250-1251
Summary A sesquiterpene-substituted 4-hydroxybenzoic acid, zonaroic acid (5), is described from the brown seaweedDictyopteris undulata (=zonarioides). The absolute stereochemistry in the zonarol (1)-chromazonarol (2) and zonaroic acid (5) series has also been defined. The occurrence of5 along with zonarol (1), the corresponding sesquiterpene-substituted hydroquinone, suggests that 4-hydroxybenzoic acid is the ring precursor as in ubiquinone biogenesis. 相似文献
16.
H. Minakata H. Komura S. Y. Tamura Y. Ohfune K. Nakanishi T. Kada 《Cellular and molecular life sciences : CMLS》1985,41(12):1622-1623
Summary Five unusual amino acids were identified as antimutagens against spontaneous mutation ofSalmonella typhimurium TA100: L-azetidine-2-carboxylic acid (1) from Liliaceae plants, -(methylenecyclopropyl)glycine (2) fromLitchi chinensis seeds, and 2-amino-4-methylhex-5-ynoic acid (3), hypoglycin A (4), and (2S, 4R)-2-amino-4-hydroxyhept-6-ynoic acid (5) fromEuphoria longana seeds. The absolute stereochemistry of5 was determined by its chiral synthesis from L-allylglycine, proving that5 is the C-4 epimer of the amino acid previously isolated from dried longan seeds.This work was partly supported by a Grant-in-Aid form the Ministry of Education, Science, and Culture, Japan, No. 57740283 (to HK). 相似文献
17.
J. L. Boeve J. C. Braekman D. Daloze M. Houart J. M. Pasteels 《Cellular and molecular life sciences : CMLS》1984,40(6):546-547
Summary The composition of the defensive secretion of larvae of 8 Nematinae species is reported. 7 derivatives have been identified: benzaldehyde, (E)-2-hexenol, (E)-2-hexenal, (E)-4-oxo-2-hexenal, geranial, neral andcis, trans-dolichodial.Maître de recherches du Fonds National de la Recherche Scientifique.We gratefully acknowledge the Fonds National de la Recherche Scientifique for financial support. We express our sincere thanks to Professor B. Zwanenburg and Dr J. M. J. Verlaak for helpful suggestions. 相似文献
18.
H. Smith G. A. Hughes B. J. McLoughlin 《Cellular and molecular life sciences : CMLS》1963,19(4):177-178
Zusammenfassung Die Totalsynthesen von (±)-Östron, (±)-d-homo-Equilenin-methyläther und (±)-iso-Equilenin werden beschrieben.
Acknowledgments. We thank the Department of Scientific and Industrial Research for the award of maintenance grants. 相似文献
Acknowledgments. We thank the Department of Scientific and Industrial Research for the award of maintenance grants. 相似文献
19.
H. J. Bestmann J. Erler W. Garbe F. Kern V. Martischonok D. Schäfer O. Vostrowsky L. T. Wasserthal 《Cellular and molecular life sciences : CMLS》1992,48(6):610-613
By means of gas chromatographic and mass spectroscopic methods, and combined GC-electroantennogram and electrosensillogram techniques, (E)-11-hexadecenal and (10E, 12E)-10,12-hexadecadienal [(E,E)-bombykal is also the main constituent of the pheromone of the silver-striped hawk-mothHippotion celerio. The biological activity of the substances was demonstrated with electroantennogram and single cell recording, and the physiological efficacy of the different hexadecadienal isomers compared.Pheromones, 79; as Pheromones, 78 is taken: Wu, Cai-Hong, and Bestmann, H. J., Chinese Science Bulletin34 (1989) 1475; pheromones, 77: Attygalle, A. B., Steghaus0Kovac, S., Ahmed, V. U., Maschwitz, U., Vostrowsky, Ol, and Bestmann, H. J., Naturwissen-schaften78 (1991) 90. 相似文献
20.
Zusammenfassung Die Reaktion des mit Eserin vorbehandelten musculus rectus abdominis des Frosches auf Acetylcholin liess sich durch Oxotremorin (2.0·10–5
M), Arecolin (2.0·10–5M), Aceclidin (1.0·10–4
M) und Carbachol (2.0·10–7
M) verstärken, während Atropin (1.0·10–5
M) hemmend wirkte. Perchlorationen in Konzentrationen über 2 · 10–4
M sensibilisierten den Froschmuskel erheblich und reduzierten die Grenzdosis, bei der eine Potenzierung durch Substanzen mit muskarinähnlicher Wirkung beobachtet wird. Alle beschriebenen Reaktionen liessen sich durch Gehirnextrakte verstärken, in denen zuvor Acetylcholin durch Kochen in alkalischer Lösung zerstört worden war.
This work was supported by NIH Grants No. NB 03007 and No. 5-F1-GM-22,905. 相似文献
This work was supported by NIH Grants No. NB 03007 and No. 5-F1-GM-22,905. 相似文献