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1.
Minhang Xin 《Steroids》2010,75(1):53-7742
An efficient and practical scheme to synthesize 2-methoxyestradiol has been developed. The key step was the copper-mediated methoxylation using ethyl acetate as a co-catalyst to introduce a methoxyl group. These synthetic procedures of four steps from 17β-estradiol as starting material gave 2-methoxyestradiol with a 61% overall yield. 相似文献
2.
P. Witzgall W. Sauter H.-R. Buser S. Rauscher H. Arn P. J. Charmillot Th. Wildbolz 《Entomologia Experimentalis et Applicata》1989,53(2):133-136
As shown by chemical analysis and field trapping, the sex pheromone of Grapholita lobarzewskii consists of a blend of (E)-8-dodecenyl acetate and (Z)-8-dodecenyl acetate. Maximum attractiveness was found at 80–95%. Dodecyl acetate and tetradecyl acetate, both present in the female gland, did not affect trap catch. G. lobarzewskii has recently gained importance as a pest of apple and plum, but has so far been referred to as Grapholita janthinana. The latter is attracted to the same two compounds, but in reversed portions (20% E).
Zusammenfassung Chemische Analysen und Feldversuche zeigen, dass das Sexualpheromon des Kleinen Fruchtwicklers, G. lobarzewskii aus (E)-8-Dodecenylacetat (Z8-12:Ac) und (Z)-8-Dodecenylacetat (Z8-12:Ac) besteht. Die grösste Lockwirkung wurde mit einem Gemisch der beiden Substanzen bei einem E-Anteil von 80–95% erzielt. Dodecylacetat (12:Ac) und Tetradecylacetat (14:Ac) wurden ebenfalls in den weiblichen Pheromondrüsen nachgewiesen, hatten aber im Freiland keinen Einfluss auf die Lockwirkung. G. lobarzewskii tritt seit einiger Zeit in der Schweiz als Schädling von Apfel und Zwetschge auf und ist an ihrem charakteristischem Frassgang leicht erkennbar. Die Art wurde bisher irrtümlich als G. janthinana bezeichnet. G. janthinana lebt auf Rosaceen, und wird vom gleichen Substanzpaar angelockt, allerdings bei umgekehrtem Mischungsverhältnis (20% E).相似文献
3.
Abstract Acetobacterium woodii was continuously grown on 3,4,5-trimethoxybenzoate as pure culture or in commensalistic combination with Pelobacter acidigallici and Desulfobacter postgatei . Under pure culture conditions the following growth parameters were determined: μ max = 0.112 h−1 , K s = 1.07 mM, Y max = 35 g/mol, and m = 0.22 mmol·g−1 ·h−1 . In coculture with P. acidigallici the affinity for the substrate increased and the K s value was found to be 135 μM. Under batch culture conditions mixed populations of A. woodii, P. acidigallici , and D. postgatei completely mineralized 3,4,5-trimethoxybenzoate to CO2 , whereas under continuous culture conditions more than 3 mM acetate remained unused. 相似文献
4.
The effect of phorbol myristate acetate, phorbol dibutyrate, ethanol, dimethylsulfoxide, phenol, and seven metabolites of phenol on metabolic cooperation were assessed as a function of mutant cell recovery from populations of cocultivated hypoxanthine-guanine phosphoribosyl transferase-deficient mutant (HGPRT–) and wild-type (HGPRT+) Chinese hamster V79 lung fibroblasts. Phorbol myristate acetate and phorbol diputyrate, two established tumor promoters, were potent inhibitors of metabolic cooperation. Ethanol and dimethylsulfoxide, solvents commonly used to prepare chemicals for testing, weakly inhibited metabolic cooperation. Phenol and phenylglucuronide had no effect on metabolic cooperation. Four oxidative metabolites (1,4-benzoquinone, catechol, hydroxyquinol and quinol) inhibited metabolic cooperation. Phenylsulfate weakly inhibited metabolic cooperation. Conversely, 2-methoxyphenol, a methylated derivative of catechol, appeared to enhance metabolic cooperation. These results generallyAbbreviations CAS
Chemical Abstracts Service
- DMSO
dimethylsulfoxide
- ETOH
ethanol
- HGPRT
hypoxanthine-guanine phosphoribosyl transferase
- HGPRT+
HGPRT-competent
- HGPRT–
HGPRT-te]deficient
- MC
metabolic cooperation
- MC+
metabolic cooperation-competent
- MC–
metabolic cooperation-deficient
- MEM
minimum essential medium
- PDBu
phorbol dibutyrate
- PMA
phorbol myristate acetate
- 6TG
6-thioguanine
- 6TGr
6-thioguanine-resistant
- 6TGs
6-thioguanine-sensitive
- V79/MC assay
Chinese hamster V79 lung fibroblast assay for metabolic cooperation 相似文献
5.
A method is presented for the rapid enzymatic determination of acetate in spent bacterial culture supernatants. The assay is based on a previously published assay for acetate kinase [Bergmeyer et al. (1974) in Methods of Enzymatic Analysis (Bergmeyer, H. V., ed.), Vol. 1, pp. 425-426, Verlag Chemie-Academic Press, New York/London], and is sufficiently sensitive to detect acetate levels of 50 microM. The assay is cheaper than commercially available assays and is particularly useful for occasional use by laboratories not equipped for routine acetate analysis using gas chromatography. The application of the assay to the measurement of acetate in bacterial cultures is described, though it should also be applicable to other biological fluids and foodstuffs. 相似文献
6.
In Vivo Substitution of Choline for Sodium Evokes a Selective Osmoinsensitive Increase of Extracellular Taurine in the Rat Hippocampus 总被引:1,自引:0,他引:1
Recent investigations have demonstrated that taurine and phosphoethanolamine (PEA) are the amino acids most sensitive to microdialysis-perfusion with reduced concentrations of NaCl. The aim of the present work was to assess the importance of Na+ deficiency in evoking this response. Further, the previously described selectivity of replacement of Cl- with acetate with respect to amino acid release was reinvestigated. The hippocampus of urethane-anesthetized rats was dialyzed with Krebs-Ringer bicarbonate buffer, and amino acid concentrations of the perfusate were determined. Choline chloride was then stepwise substituted for NaCl, and, in some cases, mannitol (122 mM) was included in low sodium-containing media. In other experiments, NaCl was replaced with sodium acetate. The dialysate levels of taurine increased selectively in response to Na+ substitution. The elevation of taurine was linearly related to the increase in choline chloride, and maximal levels amounted to 335% of basal levels. The increase in extracellular taurine was not inhibited by perfusion with medium made hyperosmotic with mannitol. Replacement of Cl- with acetate stimulated the release of taurine to 652% of resting levels. In addition, PEA levels increased to 250% of control concentration. Other amino acids were unaffected by Cl- substitution. The results show that taurine transport is considerably more sensitive to Na+ depletion than glutamate transport, which also is known to be Na+ dependent. The taurine increase evoked by low Na+ is not caused by cellular swelling as it was unaffected by hyperosmolar medium. Finally, substitution of acetate for Cl- causes a specific elevation of extracellular taurine and PEA, possibly as a result of cytotoxic edema. 相似文献
7.
Susumu Kimura 《Microbiology and immunology》1996,40(9):645-650
Reactivation of herpes simplex virus type 1 (HSV-1) occurred rapidly in cells of latently infected adult mouse trigeminal ganglia which were cultured in serum-free medium in the presence of sufficient nerve growth factor (NGF). However, HSV-1 reactivation was delayed significantly in ganglionic cultures in the absence of exogenous NGF or in cultures treated with 2-aminopurine in the presence of NGF. The delayed viral reactivation in ganglionic cultures without NGF was accelerated by treatment with phorbol myristate acetate or dibutyryl cyclic AMP. Culture conditions which affected HSV-1 reactivation did not affect replication of HSV-1 in normal ganglionic cultures. 相似文献
8.
Hamilton D Goodwin J Clarke MB du Moulin GC Liu V Caplan B Babbitt B 《Biotechnology and bioengineering》1994,43(8):700-705
An in vitro assay that measures the activation level of ex vivo activated (EVA) T cells currently being used in the adoptive immunotherapy of metastatic renal cell carcinoma has been developed. This assay is based on the ability of activated, but not resting. T cells to proliferate in response to the protein kinase C activator, phorbol myristate (PMA). To utilize this assay for in-process monitoring and control, we have begun an initial validation of the overall reproducibility of this assay. The proliferation of activated T cells in response to PMA, as measured by the mean cpm values of (3)H-thymidine incorporated, was demonstrated to have intra-assay coefficients of variation (cv's) for individual analysts that were typically less than 10% and rarely exceeded 20%. Activated T cells could be frozen and stored for at least 6 weeks with little or no deterioration in their ability to proliferate in response to PMA. Using these cells, inter-assay cv's that were typically less than 15% were obtained by individual analysts, and overall cv's of 10% to 25% were obtained for different samples assayed by different analysts at different times. This level of variability is very reasonable for a cellular assay. Furhter validation of this assay will address the issues of sensitivity, linearity and selectivity. To date, this assay has been used to analyze over 90 patient EVA cell samples and has revealed a broad range of proliferative responses to PMA. Taken together, these results suggest that this assay may be useful in defining the potency of the activated T cell used therapeutically. 相似文献
9.
K. A. Buss C. Ingram-Smith J. G. Ferry D. A. Sanders M. S. Hasson 《Protein science : a publication of the Protein Society》1997,6(12):2659-2662
The unique biochemical properties of acetate kinase present a classic conundrum in the study of the mechanism of enzyme-catalyzed phosphoryl transfer. Large, single crystals of acetate kinase from Methanosarcina thermophila were grown from a solution of ammonium sulfate in the presence of ATP. The crystals diffract to beyond 1.7 A resolution. Analysis of X-ray data from the crystals is consistent with a space group of C2 and unit cell dimensions a = 181 A, b = 67 A, c = 83 A, beta = 103 degrees. Diffraction data have been collected from the crystals at 110 and 277 K. Data collected at 277 K extend to lower resolution, but are more reproducible. The orientation of a noncrystallographic two-fold axis of symmetry has been determined. Based on an analysis of the predicted amino acid sequences of acetate kinase from several organisms, we hypothesize that acetate kinase is a member of the sugar kinase/actin/hsp70 structural family. 相似文献
10.
Summary The arcuate nucleus of the hypothalamus (AH) of male rats which had been treated either with estradiol benzoate (E2B) or cyproterone acetate (CPA) was examined ultrastructurally for the presence of whorls of endoplasmic reticulum. The incidence of whorl containing neurons (WCN) was 2–4 times higher in the AH of animals treated for 2–3 weeks with E2B or for 2 weeks with CPA than in the AH of oil treated controls. CPA is a powerful anti-androgen while E2B acts both peripherally and centrally to limit testosterone production. These findings, together with previous evidence that whorls proliferate in AH of male rats deprived of androgen by morphine treatment or castration, suggest that steroid feedback (androgen alone or both androgen and estrogen) plays an important role in AH whorl proliferation. The possibility that WCN may be LH-RH containing neurons is suggested by the close correspondence between the number and location of WCN within AH as determined in this study and the distribution of LH-RH containing cells reported by others.The authors are indebted to Schering AG for supplying cyproterone acetate for this study. This work was supported by grants DA-00259, NS-09156 and MH-14677 from U.S.P.H.S.Research Scientist Development Award MH-38894Research Scientist Development Award MH-70180 相似文献