In HMBC spectrum of 1, correlations of pyridine protons δ C 8.53 (s) with substituents aromatic carbons at δ C 146.3 (C-7), 137.6 (C-2), and oxymethine at δ C 71.3 (C-3), indicated substituents pattern (Fig.
The 1H and 13C NMR spectral data of 1 (Table 1), assumed that 1 was a tri-substituents pyridine derivative with two typical downfield protons assigned to be pyridine aromatic protons. Its IR spectrum revealed a characteristic absorption band at 1724 (C=O).
The molecular formula of 1 was determined to be C 13H 17NO 4, by a quasi-molecular ion peak at m/z 252.1222 + (calcd for C 13H 18NO 4, 252.1230) in the positive HRESIMS. Herein, we report the isolation, structural elucidation of these compounds. Unfortunately, none of these compounds exhibited significant cytotoxicity at 20 μg/mL concentration. The new alkaloids were evaluated for their cytotoxicity against human glioma initiating cell lines (GITC-3 # and GITC-18 #), glioblastoma cell lines (U-87MG and T98G), and lung cancer cell line A-549 using the reported MTS assay with DMSO as the control group. The structures of new alkaloids were elucidated by means of spectroscopic methods. major in Pakistan, and then isolated three new pyridine alkaloids, named as (–)-vincapyridines A–C ( 1– 3) trivially (Fig. In our ongoing search for alkaloids from this plant growing in different habitats, we carried out the phytochemical investigation of the aerial parts of V. Previously, we isolated non-alkaloid constituents as well as indole alkaloids from V. In addition, a number of indole alkaloids are also reported from this plant.
major while chlorogenic acid, robinin, and flavonol triglycoside are extracted from its leaves. Delphinidin glycosides have been isolated from the flowers of V. Vinca major has been used for centuries as a folk remedy in the treatment of menorrhagia and diabetes, and as an abortifacient and vulnerary. The genus Vinca (Apocynaceae), distributed through Europe, Northwest Africa, and South-west Asia, represents a group of species which are rich in indole alkaloids of diverse structural patterns, many of which are of considerable therapeutic value.
0 kommentar(er)
