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The polycondensation of D,L-aspartic acid with N,-phthaloyl-L-ornithine in phosphoric acid at 185 "C gives rise to the formation, in 60-75% yield, of random copolymers of the poly(D,L-succinimide-co-N,-phthaloyl-D,L-ornithine) type 6 possessing inherent viscosities (DMF) in the range of 5 -15 ml g-l. Copolyimides of the same compositions 6 and comparable chain lengths are obtained from aspartic acid and the copper chelate of the phthaloylornithine. Treatment of copolymers 6 with hydrazine hydrate in DMF leads to N-deprotection and opening of the intrachain succinimide rings with formation of hydrazide side groups. The resultant polyamides are of the poly(a,bD,L-asparthydrazide-co-D,L-ornithine) type 7. Shorter reaction periods give incomplete hydrazinolytic ring opening, and the remaining succinimide units are cleaved hydrolytically during the subsequent aqueous workup, thereby transforming into aspartic acid units. The polyamides so formed possess the general poly(a,bD,basparthydrazide-co-a,bD,L-aspartic acid-co-D,L-ornithine) structure 8. Both types 7 and 8 are soluble in water and, in this medium, give inherent viscosities of 5 -14 ml g-'. The potential drug-anchoring capabilities of these amine-functionalized polyamides are demonstrated by coupling reactions with model carboxylic acids. ZUSAMMENFASSUNG: Bei der Polycondensation von D,L-Asparaginsaure mit N,-phthaloyl-L-ornithin in Phosphorsaure bei 185 "C entstehen statistische Copolymere (Ausbeute 60-70%) aus Poly(D,L-succinimid-co-N,-p~thaloyl-D,L-ornithin), Formel 6, mit inharenten Viskositaten (DMF) von 5 bis 15 ml g-'. Copolyimide der selben Zusammensetzung 6 und vergleichbarer Kettenlange werden aus AsparaginsLure und dem Kupferchelat des Phthaloylornithins erhalten. Die Behandlung des Copolymeren 6 mit Hydrazinhydrat fiihrt zur Offnung der Succinimid-Kettenglieder unter Bildung von Hydrazid-Seitengruppen. Die resultierenden Polyamide sind Poly(a,bD,L-asparaginsaurehydrazid-co-D,L-ornithin), Formel 7. Kurzere Reaktionszeiten bedingen unvollstandige Ring-Offnung, und die verbleibenden Succinimid-Gruppen werden bei der folgenden Aufarbeitung hydrolytisch gespalten unter Bildung von Asparagindure-Gruppen; die so 0 1990 Hiithig & Wepf Verlag, Base1 CCC 0003-3146/90/$03.00
The polycondensation of D,L-aspartic acid with N,-phthaloyl-L-ornithine in phosphoric acid at 185 "C gives rise to the formation, in 60-75% yield, of random copolymers of the poly(D,L-succinimide-co-N,-phthaloyl-D,L-ornithine) type 6 possessing inherent viscosities (DMF) in the range of 5 -15 ml g-l. Copolyimides of the same compositions 6 and comparable chain lengths are obtained from aspartic acid and the copper chelate of the phthaloylornithine. Treatment of copolymers 6 with hydrazine hydrate in DMF leads to N-deprotection and opening of the intrachain succinimide rings with formation of hydrazide side groups. The resultant polyamides are of the poly(a,bD,L-asparthydrazide-co-D,L-ornithine) type 7. Shorter reaction periods give incomplete hydrazinolytic ring opening, and the remaining succinimide units are cleaved hydrolytically during the subsequent aqueous workup, thereby transforming into aspartic acid units. The polyamides so formed possess the general poly(a,bD,basparthydrazide-co-a,bD,L-aspartic acid-co-D,L-ornithine) structure 8. Both types 7 and 8 are soluble in water and, in this medium, give inherent viscosities of 5 -14 ml g-'. The potential drug-anchoring capabilities of these amine-functionalized polyamides are demonstrated by coupling reactions with model carboxylic acids. ZUSAMMENFASSUNG: Bei der Polycondensation von D,L-Asparaginsaure mit N,-phthaloyl-L-ornithin in Phosphorsaure bei 185 "C entstehen statistische Copolymere (Ausbeute 60-70%) aus Poly(D,L-succinimid-co-N,-p~thaloyl-D,L-ornithin), Formel 6, mit inharenten Viskositaten (DMF) von 5 bis 15 ml g-'. Copolyimide der selben Zusammensetzung 6 und vergleichbarer Kettenlange werden aus AsparaginsLure und dem Kupferchelat des Phthaloylornithins erhalten. Die Behandlung des Copolymeren 6 mit Hydrazinhydrat fiihrt zur Offnung der Succinimid-Kettenglieder unter Bildung von Hydrazid-Seitengruppen. Die resultierenden Polyamide sind Poly(a,bD,L-asparaginsaurehydrazid-co-D,L-ornithin), Formel 7. Kurzere Reaktionszeiten bedingen unvollstandige Ring-Offnung, und die verbleibenden Succinimid-Gruppen werden bei der folgenden Aufarbeitung hydrolytisch gespalten unter Bildung von Asparagindure-Gruppen; die so 0 1990 Hiithig & Wepf Verlag, Base1 CCC 0003-3146/90/$03.00
The appearance and the properties of protobiocopolymers are critically discussed. Simulating the geologically relevant primeval Earth conditions, i.e., taking into account the early atmosphere, hydrosphere, and available energies, the possibility of simultaneous appearance of some protobiocopolymers is suggested. The self‐assembling of these macromolecules in well‐defined individual systems (microspheres), their special electrical properties, such as membrane potential and semiconductivity, and their stability in rather severe physicochemtcal conditions, e.g., pH, temperature, mechanical stress, and irradiation with UV light, bring forward the “protocell” which could arise on this track on our primitive planet.
SYNOPSISThe biological and biochemical activity of protobiopolymers and their macromolecular aggregates (microspheres) synthesized in simulative primeval Earth conditions has been investigated. In vitm and in vivo experiments were carried out on bovine albumine and Tubifex egg cells, respectively. The activity of trypsin encapsulated microspheres was studied also. Intense biological and biochemical activities of the protobiopolymers and the trypsin encapsulated microspheres have been observed. It is noteworthy that the development and the division of the egg cells are influenced dramatically.theory [ 1-41 (S. W. Fox) is based on the heating of anhydrous amino acid mixtures in order to get high molecular weight (many thousand) polypeptidelike compounds, having enzymelike activities. The proteinlike polymers of alpha-amino acids synthesized by Fox [5-71, and later by others [8-141, the so-called proteinoids , could contain all the amino acids common to contemporary proteins. These "biopolymers" self-assemble in mild acid media forming very uniform 10-15-pm-diameter microspheres, which exhibit membranelike properties and selectivity in retention of certain chemical compounds [15-351.
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