Triterpenes from the leaves ofBetula ermanii
SummaryFrom the unsaponifiable fraction of an ethereal extract of the leaves ofBetula ermanii a new triterpene of the dammarane series — 20,24-epoxydammarane-3β,6α,25-trol (II) — and its 6-O-acetyl derivative (I) have been isolated.
Zur Struktur von Zeorin und Leucotylin
Die Isolierung von Zeorin und Leucotylin aus der Flechte Lecanora muralis var. muralis wird beschrieben. Wolff-Kishner-Reduktion von Zeorinon fuhrt zu 6-Desoxy-zeorin, das sich zu 6-Desoxy-zeorinin dehydratisieren last. Letztere beiden Verbindungen sind wahrscheinlich mit Hydroxyhopan bzw. Hopen-I identisch. 22-Desoxy-zeorinon liefert bei der Reduktion nach Wolff-Kishner Zeorinan. Leucotylin last sich mit Chromsaure in Essig-bzw. Schwefelsaure zu zwei verschiedenen Produkten oxydieren. Daraus folgt fur Leucotylin wahrscheinlich die Struktur eines 3-Hydroxy-zeorins.
The relation of food quantity to rumination behavior.
Preliminary work suggested that the quantity of food ingested by retarded individuals who usually ruminated following meals was related to the frequency and duration of ruminating responses. This possible relation was experimentally examined by systematically varying food quantity from regular portions to satiation levels for three retarded individuals who exhibited high levels of ruminating. A clear functional relation of food quantity to ruminating emerged, with satiation procedures producing rapid and large decreases in the relatively high frequencies and durations of ruminating characteristic of baseline food quantity conditions.