Two new naphthylisoquinoline alkaloids from stems and leaves of Ancistrocladus tectorius

Abstract

Two new alkaloids, 4'-O-demethylhamatine (1) and ancistrotectoriline C (2), were isolated from the stems and leaves of Ancistrocladus tectorius. These two compounds represent one 5,1'-coupled and one 7,6'-coupled naphthylisoquinoline alkaloid, respectively. Their structures were elucidated by 1D- and 2D-NMR spectra and other spectroscopic studies.

Five novel naphthylisoquinoline alkaloids with growth inhibitory activities against human leukemia cells HL-60, K562 and U937 from stems and leaves of Ancistrocladus tectorius

“…The molecular formula of C 26 H 31 NO 4 was Table 1 1 H, 13 C NMR data and HMBC correlations of compounds 1 and 2. . Based on the aforementioned data, compound 1 is most likely a naphthylisoquinoline alkaloid [10]. The signals of H-4 ax and H-4 eq at δ 2.60, 2.63 indicated that they were not affected by shielding effect, which suggested that the naphthyl moiety was attached to C-7 instead of C-5.…”

“…The signals of H-4 ax and H-4 eq at δ 2.60, 2.63 indicated that they were not affected by shielding effect, which suggested that the naphthyl moiety was attached to C-7 instead of C-5. Two neighboring aromatic protons instead of an ABC coupling system excluded the biaryl axis from being attached to C-1′ or C-3′, leaving only C-6′ or C-8′ for the coupling position [10]. The HMBC correlations from H-8′ to C-1′, and from H-1′ to C-8′ (see Fig.…”

“…Structurally, naphthylisoquinoline alkaloids can be sorted into different subtypes according to the location of biaryl axis between naphthyl and isoquinoline moieties. To date, the coupling modes of 5-1′ [5][6][7][8], 5-3′ [8], 5-8′ [3,4,6], 7-1′ [6][7][8]11], 7-3′ [2,9,15], 7-6′ [8,10], 7-8′ [1,2,4,17,18] and C-N [4] were reported, however, there is limited data of 5,3′ and 7,6′-coupled compounds (Fig. 1).…”

“…Its decoction of leaves and stems is traditionally used as treatment of malaria and parasite infections by the people of Li ethnicity. Previous phytochemical investigation on this plant led to the isolation of six coupling modes including 5-1′ [6,10,[12][13][14][15], 5-8′ [6], 7-1′ [6], 7-3′ [9,15] and 7-8′ [18] along with several dimers [16], meanwhile, only one 7,6'-coupled naphthylisoquinoline alkaloid [10] has been found in this plant so far, however, the ones with 5-3′ linkage have not been found in this plant yet. In the course of our studies on Li ethnomedicines, this study sought to identify the bioactive constituents present in the stems and leaves of A. tectorius.…”

“…Merr. (Ancistrocladaceae) is mainly distributed in Hainan Island, China [10]. Its decoction of leaves and stems is traditionally used as treatment of malaria and parasite infections by the people of Li ethnicity.…”