TY  - JOUR
A1  - Rauwald, Hans Wilhelm
A1  - Niyonzima, Deo-Douglas
T1  - Neue Untersuchung über Inhaltsstoffe aus Aloe-und Rhamnus-Arten, XV [1]. Homonataloin A und B aus Aloe lateritia: Reindarstellung, Konstitutions-und Konfigurationsaufklärung der Diastereomeren
T1  - A new investigation on constituents of aloe and rhamnus species, XV [1]. Homonataloins A and B from aloe lateritia: isolation, structure and configurational determination of the diastereomers
T2  - Zeitschrift für Naturforschung, C
N2  - From the leaf exudate of Aloe lateritia ENGLER the C-glucosyl com pounds homonataloin, aloeresin A and aloesin (synon. aloeresin B) were isolated together with the anthraquinone nataloeem odin-8-methylether and spectroscopically identified. Hom onataloin, widely distributed in Aloe species, was separated into homonataloin A and B by combined TLC and DCCC. In their 1 D and 2D 1H NMR spectra only the shifts of the 2′-hydroxyl protons of both glucosyl residues differ significantly, indicative of 10 S (A) resp. 10 S (B) configurations. In both com pounds the anthrone is in β-position of the D-glucopyranosyl, as determined by the large coupling constants of the anomeric protons. The 13C NMR signals are unambiguously assigned by the use of DEPT, APT and gated-decoupling methods. Only the chemical shifts of C -11 and C -14 show significant differences between both diastereomers due to the adjacent 2′-sugar hydroxyls. The two homonataloins differ mostly in optical rotation and circulardichroism due to different configurations at C - 10 of the anthrone part. The absolute configurations of the diastereomers are determined by correlation of their CD spectra with the CD spectra of the structural analogues 7-hydroxyaloins A and B, which shows that hom onataloin A is the 10 S, 1′S-compound and that homonataloin B has 10 R, 1′S-configuration.
KW  - Aloe lateritia ENGLER
KW  - Homonataloins A and B
KW  - Anthrones
KW  - Chromones
KW  - Stereochemistry
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/79915
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-799158
SN  - 0939-5075
SN  - 1865-7125
VL  - 46.1991
IS  - 3-4
SP  - 177
EP  - 182
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -