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1.
Summary TheNeurospora crassa serine auxotrophser-3 and the wild type ST4A were compared with respect to their phosphoserine and serine aminotransferase activities. The results obtained indicate no deficiency of either of these enzymes in the mutant strain.This work was supported in part by a grant to D.G. from the California Foundation for Biochemical Research. The authors also wish to thank Dr Robert G. Wolcott, formerly of the Department of Chemistry, California State University, Northridge, for his valuable advice and for the use of his department's liquid scintillation counting system. We acknowledge with appreciation the skilled technical assistance of Mr Tom Harper.  相似文献   

2.
Summary The interaction of sodium sulphite and sodium benzoate with nucleosides and DNA has been studied in vitro. Reduction in UV-absorbance was consistently noticed. However, no new products result from such interaction. It is likely that our previous observations of the effects of the 2 food preservatives on DNA synthesis and mitotis inVicia faba root meristems is not due to direct action of the chemicals at the level of genetic material.We are grateful to Professor P.A. Robbins and Dr. A.S. Herbin of the Department of Chemistry, University of Nairobi for their help.  相似文献   

3.
Summary Reevaluation of the previously proposed structure of helminthosporoside, a host-specific toxin fromHelminthosporium sacchari, reveals a sesquiterpenoid bis-digalactoside. The carbohydrate portion of the toxin was characterized by13C-NMR spectroscopy, methylation analyses, FD and FAB mass spectroscopy. The ring size and anomeric configuration of the galactose moieties were determined by utilizing a13C-NMR structural analysis method. A new partial structure is proposed.Acknowledgment. We extend special thanks to C.E. Costello, Department of Chemistry, M.I.T., Cambridge, MA, for FD mass spectral analyses, and to C.E. Ballou, Department of Biochemistry, University of California, Berkeley, CA, for FAB mass spectral analyses. We submit sincere appreciation to both V.N. Reihold, Harvard Medical School, Boston, MA, and P. Albersheim, Department of Chemistry, University of Colorado, Boulder, CO, for methylation analyses. We thank J.S. Frye at the Colorado State University Regional NMR-Center, funded by National Science Foundation grant No. DHE 78-18581, Department of Chemistry, Colorado State University, Fort Collins, Co, for high resolution CMR and NMR, and we are grateful to P.W. Jennings, Department of Chemistry, Montana State University, Bozeman, Mt, for total carbon analyses. This work was supported in part by a Herman Frasch Foundation grant to G.A. Strobel, by NSF grant PCM-78-22517, and funds from the Montana Agricultural Experiment Station. B.P. Mundy acknowledges the partial support of NSF (ISP-801149).  相似文献   

4.
Summary Two insect development inhibitors againstDrosophila melanogaster have been isolated from the leaves ofX. canadense and identified as xanthumin and 8-epi-xanthatin.Search for Insect Development Inhibitors in Plants, IV. Part III, Heterocycles10, 117 (1978).This investigation was supported in part by grants (No. 056141 and No. 376065) from the Ministry of Education of Japan. The authors express their sincere thanks to Prof. Junkichi Iwasa of this department for his encouragement and to Dr Kenji Uneyama, Department of Industrial Chemistry of this University, for13C-NMR measurements.  相似文献   

5.
Summary The square mosaic pattern of retinal cones in the guppy,Poecilia reticulata, changes during dark adaptation into a row mosaic. The functional significance of this change is discussed.Thanks are due to Dr A. Yacob, Biology Department, Mosul University, for supplying the photomicrograph for figure 2A, and to Dr C. Wise, Department of Zoology, University College, Dublin, and B. A. Collins, The Marine Biological Laboratory, Woods Hole, for technical assistance.  相似文献   

6.
Summary The antibiotic properties of 2 acidic C24H40O4 nor-sesterterpenoid peroxides, prianicin A (1) and B (2), against gram-positive and gram-negative bacteria, and against fungi are herein described. They are 4–10 times more effective than tetracycline againstbeta hemolytic Streptococcus, but significantly non-effective against a variety of gram-negative bacteria.Acknowledgment. The authors are grateful to Prof. A. Kjaer of the Organic Chemistry Department of the Technical University of Denmark, for his help and fruitful discussions.  相似文献   

7.
Summary The odorous and physiologically active substances of the secretions of Japanese stink bugs (Cydnidae) were investigated. The main components of the secretions ofM. japonensis andA. nigritus aren-tridecane andn-pentadecane together with 2-octenal and 2-decenal, while 2-hexenal is the main components in the secretion ofA. magna.The authors are indepted to Dr.Nakayama and MissEguchi (Department of Chemistry, Hiroshima University) for measurement of the mass spectra.  相似文献   

8.
Summary Large nuclear blebs have been observed in oocytes of the fish,Clarias batrachus. The bleb, which contains nucleoplasm, is finally extruded from the nucleus. The extruded body is DNase-sensitive, and it implies that some amount of DNA is extruded from the nucleus of these oocytes.Acknowledgments. We are thankful to Dr. R.K. Sharan, Department of Zoology, Patna University, for providing laboratory facilities, and to Dr V.G. Jhingran and Dr P.V. Dehadrai of ICAR for their keen interest in the work.  相似文献   

9.
Summary North American populations of the monarch butterfly,Danaus plexippus, have been found to contain pyrrolizidine alkaloids and their N-oxides. Analytical methods (TLC, GC, and GC/MS) have been developed to isolate, quantitate, and structurally elucidate the alkaloids. Examples of at least two classes of pyrrolizidine alkaloids have been identified, the macrocyclic diesters, senecionine, integerrimine, and seneciphylline, and the monoesters, echinatine, intermedine, and lycopsamine.21 November 1986This work was supported by NSF (Grants BSR-81-19391 and BSR-81-19382), and a Stauffer Chemical Company fellowship. We thank David Hodapp, Mark Stelljes, and Cordula Bruenner for technical help, Dr T.P. Krick, University of Minnesota, St. Paul, Minn., USA, for assistance in GC/MS analysis of PAs, and Dr J.A. Edgar, CSIRO, Parkville, Victoria, Australia, for samples of authentic reference compounds.  相似文献   

10.
Zusammenfassung 45tägiger Riboflavinmangel bewirkte bei männlichen Albinoratten in der Leber eine Erhöhung der Alanin-Transaminase-Aktivität sowie des Pyridoxal- und Glykogengehaltes. Diese Befunde weisen darauf hin, dass die Aktivität der Nebennierenrinde beim Riboflavinmangel erhöht ist.

Acknowledgment: The authors wish to express their sincere gratitude to Prof. S. R.Maitra, Head of the Department of Physiology, Calcutta University, for constant encouragement and for providing the laboratory facilities. The authors are also thankful to Dr.D. Sen of the Department of Applied Chemistry, Calcutta University, for translating the English summary into German.  相似文献   

11.
Summary Danaus plexippus L. andDanaus chrysippus L. have been found to store pyrrolizidine alkaloids obtained from adult food plants and it is suggested that the alkaloids contribute to the unpalatability of the butterflies to potential predators.Acknowledgment. We thank Dr.C. C. J. Culvenor for rearing some of the butterflies andJ. M. Smith for plant collection. The plants were identified by the national Herbarium, Melbourne.  相似文献   

12.
Summary A sesquiterpene isolated from the roots ofAristolochia indica (Linn.) was found to exert 100% interceptive activity and 91.7% anti-implantation activity in mice at a single oral dose of 100mg/kg b. wt. No toxic effect was found at the dose levels used.The authors wish to thank Dr S. C. Pakrashi and his associate Mr P. P. Ghosh Dastidar of Medicinal Chemistry Department for isolating the compound for this study. Thanks are also due to Director-General of Indian Council of Medical Research for granting a Junior Research Fellowship to C.S.  相似文献   

13.
Summary Specific chemical assays, including carbohydrate, hexosamines and hexuronic acid, were determined on the lens insoluble albumoid. It was noticed that the carbohydrate composition varies with age. The significance of carbohydrate in the lens in discussed.This work was supported by the College of Medicine of the University of Lagos, and financed by the British Council. The work was undertaken at the Department of Chemistry and Applied Chemistry, University of Salford, Salford (England).Special thanks are expressed to Dr L. R. Croft and Prof. G. I. Phillip for their help, support and encouragement throughout this study.  相似文献   

14.
Summary A crude extract of the venom of the marine snailConus textile Linné caused a powerful contraction in the guinea-pig isolated ileum. The extract of the venom has been fractionated, and the fractions monitored by the contractile effect. Arachidonic acid was shown to be present as an active substance.Acknowledgment. We are grateful to Mr Z. Nagahama of Okinawa island for suppling specimens ofC. textile and to Dr T. Higashijima and Prof. T. Miyazawa (Department of Biophysics and Biochemistry, Tokyo University) for 270 MHz1H-NMR-measurements.  相似文献   

15.
Summary Glycozoline and girinimbine isomers (IV andVII) were synthesized and their activity against 2 bacterial strains, viz.E. coli andS. aureus, and 2 fungal strains, viz.C. albicans andA. niger were studied. The hydroxy synthons (III) were also tested. The authors are thankful to Dr B.N. Apte, Association of Microbiologists of India, Bombay Unit, for providing some of the organisms, to Prof. A.K. De, Indian Institute of Technology, for financial assistance, to Prof. G. D. Shah, Department of Chemistry, Indian Institute of Technology for guidance, encouragement and helpful discussions.  相似文献   

16.
Summary Plasma amine oxidase activity increased from 23.4 nmol/ml/h during pregnancy to 49.5 nmol/ml/h during an extended post partum period in 10 rhesus monkeys. Comparison with non-pregnant control monkeys sampled at similar times indicated that the significant differences were in the extended post partum period.We thank Dr.C. H. Conaway and Dr.J. D. Loy of the Caribbean Primate Research Center andJ. G. Vandenbergh andW. Post of the North Carolina Department of Mental Health for the use of their facilities and animals. We also acknowledge the technical assistance ofC. H. Donnelly andMs. Suzanne Baulu. This work was supported by a grant from Dr.H. C. Robinson, Jr., through Yale University Medical School and by NIH Contract No. 71-2003.  相似文献   

17.
Summary Tryptophan can inhibit DOPA (3,4-dihydroxy phenylalanine) conversion to melanin both by the enzymatic and the nonenzymatic route. Its role has been studied in relation to vitiligo.Acknowledgments. The authors wishes to thank Dr S.C. Bhattacharyya, Bose Institute and Dr A. Sen, Department of Chemistry for their interest in the work.  相似文献   

18.
Summary The karyotypes ofTor khudree andTor tor, occurring in the Himalayan streams in India, are described. As reported earlier forT. putitora, the diploid complements in these 2 congeneric species also comprise 100 chromosomes. The modal number being 2n=50 in this family,Tor appears to be of tetraploid origin.The author is greatly indebted to Prof. G.K. Manna, and Prof. A.K. Bose, Department of Zoology, University of Kalyani, for encouragements and laboratory facilities. Financial aid from the University of Kalyani is gratefully acknowledged. Sincere thanks are also due to Dr M.K. Jyoti and Miss Anu Agarwal of the Department of Biosciences, Jammu University for their cordiality and help in various ways during my stay at Jammu.  相似文献   

19.
Summary It is shown that the Australian lungfish (Neoceratodus forsteri) synthesizes ascorbic acid in its kidney, suggesting that ascorbic acid synthesis started before the origin of the tetrapods.Acknowledgments. We would like to thank Dr G.C. Grigg, University of Sydney, Mr R. B. Humphries, Dr P.A. Janssens and Dr C.H. Tyndale-Biscoe, Australian National University, and Dr. M. Griffiths and J.C. MacIlroy C.S.I.R.O., Division of Wildlife Research for supplying the tissue.  相似文献   

20.
Summary Transection of the nervous connections between the brain and the corpus allatum (CA) inOncopeltus fasciatus does not alter the susceptibility of the CA to precocene II in vivo.The authors wish to thank Patricia Ferugia for rearing the insects; Dr D. Soderlund, Department of Entomology, New York State Agricultural Experiment Station for helpful discussions; and Dr A.O. Lea, Department of Entomology, University of Georgia for technical advice. To whom reprint requests should be addressed  相似文献   

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