caa a22 4500 469038500 CHVBK 20180323132802.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF00811548 doi (NATIONALLICENCE)springer-10.1007/BF00811548 On the synthesis of hypericin by oxidative trimethylemodin anthrone and emodin anthrone dimerization: Isohypericin [Elektronische Daten] [Heinz Falk, Gerhard Schoppel] Zur Synthese von Hypericin durch oxidative Dimerisierung von Trimethylemodinanthron und Emodinanthron: Isohypericin Summary: The base catalyzed oxidative dimerization of emodin anthrone exclusively yields hypericin. However, on oxidative dimerization of trimethylemodinanthrone a mixture of hexamethylhypericin and hexamethylisohypericin was obtained. Chromatographic separation of the hexabenzoyl derivatives was achieved, and by saponification about equal amounts of hypericin and isohypericrin were produced. Isohypericin could be characterized for the first time by its spectroscopic data and its protonation and deprotonationpK a andpK a * values. Springer-Verlag, 1992 Trimethylemodin anthrone nationallicence Emodin anthrone nationallicence Hypericin nationallicence Isohypericin nationallicence Spectroscopic properties nationallicence pK a-values nationallicence Synthesis nationallicence Falk Heinz Institut für Chemie, Johannes-Kepler-Universität Linz, A-4040, Linz, Austria aut Schoppel Gerhard Institut für Chemie, Johannes-Kepler-Universität Linz, A-4040, Linz, Austria aut Monatshefte für Chemie / Chemical Monthly Springer-Verlag 123/10(1992-10-01), 931-938 0026-9247 123:10<931 1992 123 706 https://doi.org/10.1007/BF00811548 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00811548 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Falk Heinz Institut für Chemie, Johannes-Kepler-Universität Linz, A-4040, Linz, Austria aut NATIONALLICENCE 700 1- Schoppel Gerhard Institut für Chemie, Johannes-Kepler-Universität Linz, A-4040, Linz, Austria aut NATIONALLICENCE 773 0- Monatshefte für Chemie / Chemical Monthly Springer-Verlag 123/10(1992-10-01), 931-938 0026-9247 123:10<931 1992 123 706 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer