3,4-Dimethoxy-3,4-desmethylendioxycubebin, ein neues lignan aus aristolochia triangularis

Melanogenesis Stimulation in Murine B16 Melanoma Cells by Piper nigrum Leaf Extract and Its Lignan Constituents

“…Table 2]. On the basis of comparison of the physicochemical data of 1 and 2 with those of the reported data, [7][8][9][10][11][12][13][14] 1 and 2 were identified as (Ϫ)-cubebin and (Ϫ)-3,4-dimethoxy-3,4-desmethylenedioxycubebin, respectively. The comparisons of 1 H-and 13 C-NMR spectral data of 1 with the reported data 11,13,14) are shown in Tables 1 and 2, respectively.…”

“…As to the substituted position of two substituted benzyl moieties in a dibenzylbutyrolactol class of lignans, EI-MS spectral data have been informative in the structural determination, because it has been noted that C 7 -C 8 fission is preferable to C 7Ј -C 8Ј fission in the EI-MS spectra of lignans belonging to the dibenzylbutyrolactol class. 10) In fact, a fragment ion produced by C 7 -C 8 fission was observed at m/z 203 [corresponding to M ϩ (m/z 372)Ϫ18 (H 2 O)Ϫ151 (3,4-dimethoxybenzyl ion)] with 16% relative intensity in the EI-MS spectra of 2, whereas a fragment ion produced by C 7Ј -C 8Ј fission observed at m/z 219 [corresponding to M ϩ Ϫ18Ϫ135 (3,4-methylenedioxybenzyl ion)] had 5% relative intensity. In the EI-MS spectra of 3, a fragment ion produced by C 7 -C 8 Stimulation of Melanogenesis in Cultured B16 Melanoma Cells Melanogenesis activity in the cultured murine B16 melanoma cells is closely related to the amount of produced melanin which is estimated from the sum of the amount of melanin retained in the cells (intracellular melanin) and that excreted into the cultured medium (extracellular melanin).…”

Configurational analysis of cubebins and bicubebin from Aristolochia lagesiana and Aristolochia pubescens

“…However, the configuration of this anomeric center is still unclear, as with other butyrolactol lignans (Brown and Daugan, 1989;Li et al, 2003;Gö zler et al, 1996;Bhandari et al, 1998;Rü cker and Langmann, 1978;Barrero et al, 1994;Cambie et al, 1985).…”

Inhaltsstoffe vonAristolochia triangularis*

“…Ober die Struktur eiries neuen Lignans aus A. triangularis, des 3,4-Dimethoxy-3,4-desmethylendioxycubebins, haben wir schon berichtet [14]. Von diesem konnte die ebenfalls bisher unbekannte isomere Verbindung 3 ,4 '-Dimethoxy-3',4 '-desmethylendioxycubebin chromatogrphisch nicht abgetrennt werden.…”

“…Eine Trennung gelang erst nach Oxidation der Halbacetale zum Gemisch der eatsprechenden Lactone. Diese unterscheiden sich charakteristisch in ihrer massenspektrometrischen Fragmentierung [14]. thy!ierungsprodukt des Pluviatolids [15].…”