6 resultados
New treatment options are needed for medullary thyroid carcinoma (MTC), a highly metastasizing neuroendocrine tumor that is resistant to standard radiotherapy and chemotherapy. We show that the following shikonin derivatives inhibit cell proliferation and cell viability of the MTC cell line TT:
The root extracts of Onosma leptanhtha were evaluated for their anti-iflammatory and cytotoxic activities. The cyclohexane extract, which appeared as the most active in both assays, has been further subjected to bioassay-directed fractionation to afford the naphthazarine derivatives:
In the present study, five root extracts of Onosma visianii Clem were investigated for their in vitro cytotoxic activity. On the basis of HPLC-PDA analysis, these extracts have proved to be a rich source of naphthoquinones as natural colourants for food and cosmetic industry. All investigated root
In the present work we modified the procedure for isolation of naphthoquinones α-methylbutyrylshikon ( 1 ), acetylshikonin ( 2 ) and β-hydroxyisovalerylshikonin ( 3 ) from Onosma visianii Clem. We also investigated possible mechanisms of 1 , 2 and
Activity-guided fractionation of a petroleum ether-soluble extract of the roots of Onosma paniculata, which has been shown to affect the cell cycle and to induce apoptosis in melanoma cells, led to the isolation of several shikonin derivatives, namely, β-hydroxyisovalerylshikonin (1), acetylshikonin
In this study, the antibacterial and cytotoxic activities of isolated compounds from the roots of Onosma visianii were investigated. By using different chromatographic techniques and appropriate spectroscopic methods, the seven naphthoquinones were described: deoxyshikonin ( 1 ), isobutyrylshikonin