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1.
Summary The host-selective phytotoxin victorin, produced by the fungusCochliobolus victoriae, was found to be at least partially peptidic in nature, and did not contain victoxinine. The exact mass of the M-H ion was measured by FABMS as 795.1877. Derivatives of three major acid hydrolysis products were isolated. The structures of the corresponding amino acids were assigned as 2S,3R-3-hydroxyleucine, 5,5-dichloroleucine, and 3-hydroxylysine. A into victorin by the fungus in vivo.  相似文献   

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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   

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Antimutagenic unusual amino acids from plants   总被引:2,自引:0,他引:2  
Five unusual amino acids were identified as antimutagens against spontaneous mutation of Salmonella typhimurium TA100: L-azetidine-2-carboxylic acid (1) from Liliaceae plants, alpha-(methylenecyclopropyl)glycine (2) from Litchi 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) from Euphoria longana seeds. The absolute stereochemistry of 5 was determined by its chiral synthesis from L-allylglycine, proving that 5 is the C-4 epimer of the amino acid previously isolated from dried longan seeds.  相似文献   

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Zusammenfassung Die Konformation einiger natürlicher Aminosäuren wird auf Grund einer erweiterten Hückel-Molekular-Orbital-Theorie berechnet.

Recipient of a Public Health Service Research Career Development Award No. AM1159.  相似文献   

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Zusammenfassung N-(DL-Seryl)-N-(2,3,4-trihydroxybenzyl)hydrazin (Ro 4-4602) bewriktin vitro starke Hemmung der Decarboxylase, die durch Pyridoxal-5-phosphat nicht und durch Dialyse nur wenig vermindert werden kann. Nach i.p. Applikation der Substanz kommt es zu starker Verminderung der Decarboxylase-Aktivität und zu mässiger Herabsetzung von 5-Hydroxytryptamin und Noradrenalin in verschiedenen Organen. Monoaminoxydase des Gehirns wirdin vivo durch Ro 4-4602 nicht beeinflusst.  相似文献   

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This paper presents the results of a study to determine whether new forecasting technologies might be of use to electric utilities for sales forecasting up to 3 years into the future. The methods considered included ordinary least squares on dynamic structural models, autocorrelated error models, adaptive variance and adaptive parameter models. Overall, the more adaptive models performed best, but most of the methods proved vastly superior to simple least squares models which do not take dynamics into account.  相似文献   

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Riassunto Sono stati esaminati comparativamente tre reagenti per la titolazione di C3, rispettivamente allestiti con siero di cavia inattivato con zymosan, formalina e «Liquoid». Le differenze esistenti tra essi sono state analizzate e discusse in base alle attuali conoscenze sulla natura del terzo componente complementare.

Supported in part by Contract DA-49-007-MD-696 with the Office of the Surgeon General, Department of the Army.  相似文献   

8.
Riassunto Viene confermato che la sintesi fotochimica degli aminoacidi da paraformaldeide catalizzata da composti inorganici avviene sia in presenza sia in assenza di una sorgente inorganica di azoto fissato (aria). Inoltre viene dimostrato che i tipi di aminoacidi prodotti come la velocità di formazione dipendono dal catalizzatore usato.

Supported in part by the Air Force Cambridge Research Laboratories, under Grant AF EOAR No. 63–116, through the European Office of Aerospace Research, United States Air Force.  相似文献   

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Zusammenfassung Durch katalytische Hydrierung von C-aktivierten Carbobenzoxyaminosäurederivaten, z. B. von gemischten Anhydriden und aktivierten Estern, werden via die Carbaminsäurederivate die entsprechenden Leuchsschen Anhydride und Polypeptide erhalten.

This work was supported by grants from the National Institutes of Health, U.S. Public Health Service (G.M. 06579 and G.M. 08795).  相似文献   

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Summary Due to the electric polarisation induced by the carbon and nitrogen atoms, the molecules of the nucleotide bases present a stereo-asymmetry. The DNA right-handed double helix is determined by the asymmetry of the nucleotide bases and it is concordant with the right-handed -helix of the polypeptide molecules formed by L-amino acids.  相似文献   

14.
Résumé La composition de l'amine acide libre dans les deux espèces deTubularia a été examinée au moyen de la chromatographie. Les tissus d'hydranthe deT. crocea avaient 21 amines acides libres dont 18 ont été identifiées dans les hydrocauli et dans les hydranthes régénérés deT. crocea, 19 dans les hydranthes deT. spectabilis et 14 dans les hydrocauli deT. spectabilis. La différence principale entre les hydranthes et les hydrocauli réside dans la distribution de certaines taches non-identifiées qui apparurent dans les chromatogrammes developpés avec la ninhydrine et les réactifs pour les groupes des imidazoles, guanidines, ou sulfhydriles.

Part of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Florida State University. Aided by a National Science Foundation Predoctoral Fellowship and a National Science Foundation Grant to Dr. C. B.Metz, Contribution number 122 from the Oceanographic Institute, Florida State University.  相似文献   

15.
Zusammenfassung Auf Grund vorausgegangener Experimente, besonders über degenerierte Triplettcodons, wird ein Verfahren entwickelt, aus dem sich die Austauschmöglichkeiten von Aminosäuren in Eiweißstoffe ergeben, dann nämlich, wenn im Codon nur je eine Base des Tripletts ersetzt wird.  相似文献   

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Summary Tumor cells isolated from a murine fibrosarcoma were grown in primary culture for two days and then separated on a basis of size by velocity sedimentation. Centrifugal elutriation and STAPUT methods were compared for their ability to isolate biophysically unique tumor subpopulations. The isolated cell fractions were assayed for cell number, incorporation of triatiated thymidine and Coulter volume. Both methods were comparable with regard to ability to separate tumor cells on a basis of size. Elutriation had the advantage of speed but required sophisticated equipment. The STAPUT method was less expensive but required somewhat longer times for separation.Supported in part by NIH-NCI grants No. CA-06294 and CA-18628.  相似文献   

18.
Summary Hydroxy amino acids are synthesized from unsaturated aliphatic carboxylic acid using aqueous ammonia under conditions of contact glow discharge electrolysis.This work was supported partly by a grant from the Ministry of Education.  相似文献   

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