Homer C. Scarborough

Bio: Homer C. Scarborough is an academic researcher. The author has contributed to research in topics: Thymine & Uracil. The author has an hindex of 1, co-authored 1 publications receiving 21 citations.

The synthesis of uracils as anticonvulsants.

Abstract: A convenient laboratory synthesis has been devised by which a series of new 5‐alkyluracils has been prepared for evaluation as anti‐convulsants. Certain other 5‐substituted uracils and their N,N‐dimethyl derivatives, and related compounds, have also been synthesized. The anticonvulsant activity of uracil and thymine has been surpassed by several members of this new series.

Nucleosidsynthesen, VII. Eine einfache Synthese von 2-Thiopyrimidin-nucleosiden

Abstract: Silylierte 2-Thiouracile reagieren mit acylierten Halogenzuckern in Gegenwart von Silberperchlorat in Benzol in hohen Ausbeuten zu den acylierten 2-Thiopyrimidin-nucleosiden. Analog werden 2-Thiocytidin und 2-Thiouridin-5-essigsaure-methylester, zwei seltene Nucleoside aus t-RNA, dargestellt. Der Mechanismus der Reaktion wird diskutiert. Syntheses of Nucleosides, VII. A New Synthesis of 2-Thiopyrimidine Nucleosides Silylated 2-thiouracils react with acylated 1-halosugars in the presence of silver perchlorate in benzene to give the acylated 2-thiopyrimidine nucleosides in high yields. 2-Thiocytidine and methyl 2-thiouridine-5-acetate, two rare nucleosides from t-RNA, are prepared analogously. The mechanism of the reaction is discussed.

Synthesis of 2′-Deoxypyrimidine Nucleosides via Copper (I) Iodide Catalysis

Abstract: The coupling of various 5-substituted-2,4- disilyl pyrimidines with a–2-deoxy-3,5-di-p-toluyl ribofuransyl chloride in the presence of copper (I) iodide in chloroform yields predominantly β-nucleosides (>15/1 β/α selectivity in some cases) in >90% overall yields.

Regioselective direct C-H arylations of protected uracils. Synthesis of 5- and 6-aryluracil bases.

Abstract: A new regioselective synthesis of 5- and 6-aryluracil bases based on direct C–H arylations of diverse 1,3-protected uracils has been developed. Benzyl-protected uracils were selected as the most practical in terms of stability during the arylation and facile cleavage of the benzyl groups. Pd-catalyzed C–H arylations in the absence of CuI gave preferentially 5-aryl-, whereas the reactions in the presence of CuI gave 6-aryl-1,3-dibenzyluracils. Final deprotection either by transfer hydrogenolysis over Pd/C or by treatment with BBr3 gave the desired free arylated uracil bases in good yields.

Uridine anticonvulsant effects: selective control of nucleoside incorporation in experimental epilepsy.

Abstract: Summary This study was designed to determine whether uridine is the only nucleoside that has anticonvulsant properties and is incorporated selectively into nucleic acids of epileptogenic regions, whether it enhances or inhibits epileptic activity and/or subsequent incorporation of nucleoside, and whether a change in RNA or DNA synthesis in epileptic regions is related to the etiology of seizures. Of all the nucleosides tested, only uridine exerted an anticonvulsant effect related to selective increase in nuclear neuronal RNA of epileptic regions. The time between administration of uridine and anticonvulsant effect on ECoG responses was consistent with the time required for maximal incorporation of uridine into nuclear RNA of brain components. Uridine also affected specifically the amount and cellular localization of all other nucleosides, in both control and epileptic animals. Increase in RNA but not in DNA synthesis, in both primary and mirror focal regions, was related to epileptic phenomena. It is proposed that increased synthesis of nuclear neuronal RNA in primary and mirror foci of penicillin-induced epilepsy is directly related to the etiology of seizures and that selective alteration of uridine concentration may be responsible for both initiation and termination of epileptic activity. REsume On a concu cetti etude pour preciser si 1'uridine est le seul nucleoside ayant des proprietes anticonvulsivantes et s'il est selectivement incorpore dans les acides nucleique des regions epileptogenique; pour voir si 1'uridine augmente ou diminue 1'activiteepileptique a la suite de l'incorporation du nucleoside, et si les modifications dans la synthese du RNA ou DNA dans les regions epileptiques sont en relation avec l'etiologie des crises. Parmi tous les nucleosides testes, seul 1'uridine avait une action anticonvulsivante en relation avec une augmentation selective du RNA nucleaire des neurones des regions epileptiques. L'intervalle de temps entre 1'administration d'uridine et l'effet anticonvulsivant sur les reponses ECoG etait en accord avec l'intervalle de temps necessaire a l'incorporation maximale de 1'uridine dans le RNA nucleaire des composants cerebraux. L'uridine interessait aussi specifiquement la quantite et la localisation cellulaire de tous les autres nucleosides dans les animaux de controle et ceux epileptiques. L'augmentation de la synthese du RNA mais non du DNA dans les regions primaires et de celles en miroir etait en relation avec les phenomenes epileptiques. On suggere que 1'augmentation de la synthese neuronale nucleaire du RNA dans le foyer primaire et en miroir produit par la penicilline est en relation directe avec l'etiologie des crises et que 1'alteration selective de la concentration d'uridine peut etre responsable du commencement et de la fin de l'activiteepileptique. RESUMEN Este estudio se ha programado para determinar si la uridina es el unico nucleosido que tiene propiedades anticonvulsivantes, si se incorpora selectivamente en los acidos nucleicos de los focos epileptogenos, si acentua o inhibe la actividad epiletogenica subsiguiente a la incorporacion de nucleosido y si algun cambio en la sintesis de RNA o DNA en regiones epileptogenicas puede estar imbricado en la etiologia de los ataques. De todos los nucleosidos estudiados solo la uridina ejercio un efecto anticonvulsivante relacionado con un aumento selectivo de RNA nuclear en regiones epileptogenicas. El tiempo transcurrido entre la administration de uridina y el efecto convulsivo en las respuestas del ECoG fue congruente con el tiempo requerido para una maxima incorporacion de la uridina en RNA nuclear cerebral. La uridina tambien altero especificamente la cantidad y la localization cerebral de los restantes nucleosidos en los animales control y en los epilepticos. El aumento de la sintesis de RNA y no de DNA, tanto en focos primarios como en los focos “en espejo,” estaba relacionado con los fenomenos epilepticos. Proponemos que el aumento de la sintesis de RNA nuclear neuronal en focos primarios y “en espejo” de las epilepsyias inducidas por penicilina, esta directamente relacionado con la etiologia de las epilepsias y que la alteration selectiva de la concentration de uridina puede ser responsable de la iniciacion y termination de la actividad epileptica. ZUSAMMEnfassung Diese Studie soil klairen, ob Uridin das einzige Nukleosid ist, das antikonvulsive Eigenschlaften hat, ob es selektiv in Nukleinsauren epileptogener Regionen eingebaut wird, ob es als Folge der Inkorporation der Nukleoside die epileptische Aktivitat vermehrt oder inibiert, ob schliesslich eine Anderung der RNA oder DNA-Synthese in epileptischen Regionen Beziehungen zur Atiologie der Krampfe aufweist. Von alien getesteten Nukleosiden zeigt nur Uridin eine antikonvulsive Wirkung die in Beziehung stand zur selektiven Erhohung der RNA in den Nervenzellkernen epileptischer Regionen. Die Zeit zwischen Verabfolgung von Uridin und antikonvulsiver Wirkung auf die elektrokortikographischen Antworten entsprach der Zeit, die erforderlich ist fur die maximale Inkorporation von Uridin in die RNA von Zellkernen der Hirnbestandteile. Uridin beeinflusste ferner spezifisch die Menge und die zellulare Lokalisation alter anderen Nukleoside sowohl bei Kontrolltieren wie bei epileptischen Tieren. Die Steigerung der RNA- aber nicht der DNA-Synthese sowohl im primaren wie im Spiegelfokus stand in Beziehung zu dem epileptischen Phanomen. Wir nehmen an, dass die vermehrte Synthese der nuklearen neuronalen RNA im primaren und Spiegelfokus der Penicillin induzierten Epilepsie direkte Beziehung hat zur Atiologie der Krampfe und dass die selektive Verainderung der Uridinkonzentration sowohl verantwortlich ist fur den Beginn wie fur die Beendigung der epileptischen Aktivitat.