Die Isolierung der roten Antibiotica β‐Rubromycin und γ‐Rubromycin wird beschrieben. – β‐Rubromycin isomerisiert sich in siedendem Pyridin quantitativ zu α‐Rubromycin und wird durch verd. Mineralsäuren unter Verseifung eines Methoxyls in γ‐Rubromycin verwandelt. γ‐iso‐Rubromycin entsteht: 1. Aus γ‐Rubromycin durch Erhitzen mit Pyridin oder konz. Schwefelsäure, 2. aus α‐Rubromycin durch Chlorwasserstoff in Chloroform. – β‐Rubromycin (11) enthält als Chromophor 8‐Hydroxy‐5.7‐dimethoxy‐naphthochinon‐(1.2), das über Sauerstoff an C‐4 und eine Methylengruppe an C‐3 mit dem Rest des Moleküls verbunden ist. – Chromophor der drei anderen Rubromycine (12, 13, 14a) ist 5.8‐Dihydroxy‐2(bzw. 7)‐methoxy‐naphthochinon‐(1.4) – in α‐Rubromycin am 5‐Hydroxyl methyliert –, an dem über Sauerstoff an C‐7 (bzw. C‐2) und Kohlenstoff an C‐6 (bzw. C‐3) der Rest des Moleküls hängt.
1. 14C-Diethylene glycol (DEG), administered orally to rats at 1, 5, and 10 ml/kg, gave elimination half-lives of 6, 6, and 10 h, respectively, from urinary excretion data. Half-logarithmic plots of urinary 14C excretion rates versus time indicated zero-order elimination for the first 9 and 18 h after oral doses of 5 and 10 ml of 14C-DEG/kg, respectively. 14C-DEG urinary elimination kinetics changed into first-order 6, 9, and 18 h after oral doses of 1, 5, and 10 ml/kg, with a half-life of 3 h. 2. After oral doses of 3 and 5 ml ethylene glycol (EG)/kg, half-lives of 4.5 and 4.1 h were estimated from cumulative urinary excretion data for non-metabolized EG. A half-life of 2 h was determined from half-logarithmic plots of urinary excretion rates of non-metabolized EG after the same oral doses of EG. 3. The urinary concentrations of non-metabolized DEG and its metabolite, 2-hydroxyethoxyacetic acid (2-HEAA), determined by high-resolution n.m.r. spectroscopy in the urine of rats doses with DEG were 61-68% and 16-31% dose, respectively. 4. Urinary concentrations of non-metabolized EG and its metabolite, glycolic acid (GA), determined by n.m.r., gave 62-67% for non-metabolized EG and 28.7% for GA following oral doses of EG. 5. Oxidation of DEG and EG in rats was accompanied by a change of urinary pH, reflecting metabolic acidosis. 6. Comparison of the KM for DEG oxidation in vitro by ADH with that of ethanol oxidation, showed a 680-fold difference in substrate affinity. DEG inhibited ethanol oxidation non-competitively, the Ki being 0.44 M.
Oral doses of 1 and 5 ml/kg 14C-diethylene glycol (DEG) given to rats were rapidly and almost completely absorbed, the invasion constants being 2.95 h-1 and 4.24 h-1. The kinetics of invasion were determined with the method of residuals (Rowland and Tozer 1989) and by reconstruction of the invasion curves according to Kübler (1970). 14C-DEG was rapidly distributed from the blood into the organs and tissues in the order kidneys > brain > spleen > liver > muscle > fat, i.e. the same order as the blood flow. The relative volume of distribution, app. VD, was determined at 298 ml, indicating distribution over the whole body. After oral doses of 1, 5, and 10 ml 14C-DEG/kg 64, 87, and 91% of 14C activity in rat blood disappeared in 12-16 h with a half-life of 3.4 h and the remaining 9, 5, and 4% with half-lives of 39 h, 45 h, and 49 h. A total of 73-96% of 14C activity in blood was excreted with the urine and 0.7-2.2% with the faeces. From the cumulative urinary excretion kinetics half-lives of 6 h were determined for doses of 1 and 5 ml/kg and 10 h for the dose of 10 ml/kg. After doses of 5 ml/kg and 10 ml/kg 14C-DEG semi-logarithmic plots of elimination rate versus time were constant for 5 and 9 h, respectively, indicating that DEG accelerated its renal elimination by inducing osmotic diuresis. Thereafter urinary excretion followed first order kinetics with elimination half-lives of 3.6 h. After oral doses of 5 ml/kg 14C-DEG given to rats of 336 g body weight with an app. VD of 297 ml, the total clearance of 14C activity was determined at 63 ml/h, and the renal clearance of unmetabolized DEG was 66 ml/h. The ratio of ClDEG to Cl(inulin) = 0.64 indicated that DEG and its metabolite 2-hydroxyethoxyacetate (2-HEAA) were reabsorbed from the tubuli into the blood capillaries. DEG produced metabolic acidosis, which was completely balanced after doses of 1 and 5 ml/kg, but doses greater than 10 ml/kg produced non-compensated metabolic acidosis, hydropic degeneration of the tubuli, oliguria, anuria, accumulation of urea-N, and death in uraemic coma.
Aus einem Srrepromyces-Stamm wurden drei kristallisierte, als q-, <-und ePyrromycinon bezeichnete Farbstoffe isoliert. q-Pyrromycinon ist ein l .4.6-Trihydroxy-carbomethoxy-ilthyl-tetracenchinon, <-und t-Pyrromycinon sind Derivate des 1.4.6-Trihydroxy-7.8.9.IO-tetrahydro-tetracenchinons rnit einer Carbomethoxygruppe, einer bithylgruppe und einer bzw. zwei Hydroxygruppen. Durch Dehydrierung bzw. Wasserabspaltung lassen sie sich in q-Pyrromycinon iiberfilhren. Fur alle drei Pyrromycinone werden Konstitutionsformeln aufgestellt. Die Pyrromycinone stehen den Rhodomycinonen nahe, rnit denen sie ilber das aus q-Pyrromycinon dargestellte q-Iso-pyrromycinon strukturell verknupft werden konnten. Aus Erdproben verschiedener Herkunft wurden in unserern lnstitut rnehrere Strepron?vces-Sti i mmeyces-St&nme isoliert3). deren Mycel und 1.4.6-Trihydroxy-tetracenchinons (III).Derivate des Tetracenchinons sind bisher in der Natur nicht aufgefunden worden. Descarbomethoxy-q-pyrromycinon lieferte bei der KmN-Row-Oxydation 0.6 Moll.fluchtiger Saure, die im Papierchromatogramm als Essigsaure 14) identifiziert wurde. Wie nicht anders zu erwarten, enthalt es demnach ebenso wie q-Pyrromycinon eine C-Methylgruppe. Seine Bruttoformel C20H1405 ist um CH2 groBer als die eines Trihydroxy-methyl-tetracenchinons, was ebenso, wie beim q-Pyrromycinon, nur dadurch erklart werden kann, daD eine khylgruppe vorhanden und Descarbomethoxyq-pyrromycinon somit ein 1.4.6-Trihydroxy-athyl-tetracenchinon (IV b) ist.Hier wie beim q-Pyrromycinon stiitzt sich die Annahme. daB eine Xthylgruppe vorliegt, auf die C,H-Werte von Descarbomethoxy-q-pyrromycinon bzw. 7-Pyrromycinon. die auf eine um CH2 kleinere Formel schlecht passen. Unabhangig davon wird die Anwesenheit einer Xthylgruppe dadurch bewiesen, daB, wie unten gezeigt, bei der Oxydation von <-und ePyrromycinon (die beide in q-Pyrromycinon libergehen k6nnen) neben Essigsaure auch Propionsaure entsteht.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.