No abstract

No abstract

No abstract

Jahrg. 91 Bei Verseifung mit alkohol. Kalilauge crfolgte Bildung der blaufluoreszierenden Harmancarbonsaure-(3) (Ill). RF-Wert 0.25, Laufmittel 5-prOZ. Ammoniak. Eine qualitative Auswertung des UV-Spektrums des Esters ergab ubereinstimmung mit dem in der Literatur beschriebenen Harmanspektrumzl). A, , , = 236my. 270my; kleinere Maxima A , , , = 33 I my, 345 my. Zum Vergleich wurde die Ausmessung des Harmanspektrums in Methanol wiederholt und die genaue Lage der Maxima bestimmt: A, , , = 212mp, log E = 4.287; 234mp, log E = 4.535; 287.5mp, logc = 4.171; 335mp. loge = 3.607; 348.5my, log& = 3.620 (Methanol, r = 0.0142 bzw. 0.0071 g/l). Die Peptidbindung in Dipeptiden wird in Anwesenheit geeigneter Metallionen gelost. -Der metallionenkatalytischen Spaltung liegt die Bildung eines zerfallsfahigen Reaktionszwischenproduktes durch koordinative Bindung desKatalysators an die freien Elektronenpaare des Amino-und des Carbonamid-Sticksioffes des Dipeptids zugrunde. -Die ,,peptidatische" Wirksamkeit der Katalysatoren nimmt in der Reihenfolge Ce4@ + Ce3@ -+ La3O ab. --Fur die gepriiften Dipeptide ergibt sich eine Stabilitatsreihe, ahnlich wie sie friiher bei der enzymatischen Spaltung und neuerdings bei der Hydrolyse mittels Ionenaustauscher gefunden worden ist.

Les auteurs sont seuls responsables des opinions exprim6es dans ces br6ves communications. -Ftir die Kurzmitteilungen ist ausschliesslich der Autor verantwortlich. -Per le brevi comunicazioni 6 responsabile solo l'autore. -The editors do not hold themselves responsible for the opinions expressed in the authors' brief reports. -OTBeTCTBeHH0CTb 3aK0p0TKHe C006meHH~ HeC~T HC~amqHTenbH0 aBT0p.--]~1 responsable de los informes reducidos, est& el autor. A New Phenylquinolizidol of Heimia salicifoliaIn continuing our studies on the alkaloids of Heimia salicifolia Link and Otto we have established the presence of 2-hydroxy(a)-4-(3-hydroxy-4-methoxyphenyl) (e)-trans- During investigations of the sequential appearance of the alkaloids of H. salici/olia the presence of two unknown alkaloids in 7-day-old seedlings was observed ~. We continued with these studies and have determined that one of the compounds is the phenylquinolizidol I by direct comparison with a synthetic sample. We found that I accumulates only in relatively young seedlings. It could not be found in the seeds, in 2-week-old seedlings a in 5-6-month-old plantlets, or in mature plants.Seedlings (5-day-old) and some ungerminated seeds were dried (6.7 g), and extracted (blender) with acetate buffer at pH 5. Undesirable material was eliminated from this solution with CttC1 a. CHC13-MeOH (4:1) extraction at pIK 8.5-9, gave the desired alkaloids (25.7 mg). R2 I, RI =OH, R2=HII, R1 = I'1, R2 = OH OCH3 III, R~, R=, = 0 Compound I, (0.6 rag) was obtained by preparative TLC [A1203GF254, NH~ saturated benzene-MeOH (190:10), double development, followed by NH~ saturated EtOAcEtOtt (210:2.5)]. That the natural compound was identical with the synthetic compound was verified by TLC (3 alumina and 7 silica gel systems) and by mass spectrometry.I possesses the same stereochemistry (C-2 oxygen axial, phenyl ring equatorial, nitrogen spin pair axial) as all the Heimia alkaloids. We have not detected the equatorial alcohol in any plant material analyzed.Condensation of pelletierine with isovanillin 6, ~ gave