Guanidine Alkaloids from Monanchora arbuscula: Chemistry and Antitumor Potential |
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| Authors: | Elthon G. Ferreira Diego V. Wilke Paula C. Jimenez Julieta R. de Oliveira Otília Deusdênia L. Pessoa Edilberto R. Silveira Francisco A. Viana Cláudia Pessoa Manoel Odorico de Moraes Eduardo Hajdu Letícia Veras Costa‐Lotufo |
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| Affiliation: | 1. Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Rua Cel. Nunes de Melo, 1127, 60430‐270 Fortaleza, Ceará, Brazil (phone: 55?85?3366?8255;2. fax: 55?85?3366?8333);3. Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, CE, Brasil;4. Departamento de Química Organica e Inorganica, Universidade Federal do Ceará, Fortaleza, CE, Brasil;5. Departamento de Química, Universidade do Estado do Rio Grande do Norte, 59610‐210, Mossoró‐RN, Brasil;6. Museu Nacional do Rio de Janeiro, Universidade Federal do Rio de Janeiro, RJ, Brasil |
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| Abstract: | Five guanidine alkaloids, mirabilin B ( 1 ), 8bβ‐hydroxyptilocaulin ( 2 ), ptilocaulin ( 3 ), and a mixture of the 8β‐ and 8α‐epimers, 4 and 5 , of 8‐hydroxymirabilin (1,8a;8b,3a‐didehydro‐8‐hydroxyptilocaulin), were isolated from Monanchora arbuscula colonies collected off the northeastern Brazilian coast. All structures were elucidated by spectroscopic analysis, including 1D (1H‐, 13C‐ (BB), and 13C‐DEPT) and 2D (COSY, HSQC, and HMBC) NMR experiments, and comparison with the literature data. The cytotoxicity of the isolated compounds were evaluated against four tumor cell lines, showing that mirabilin B ( 1 ) and the two epimers were inactive, while 8bβ‐hydroxyptilocaulin ( 2 ) and ptilocaulin ( 3 ) presented IC50 values in the range of 7.9 to 61.5 μM , and 5.8 to 40.0 μM , respectively. Further studies on the mechanism of action of ptilocaulin, using HL‐60 leukemia cells, demonstrated that this guanidine compound induced apoptosis of the treated cells. |
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| Keywords: | Monanchora arbuscula Guanidine alkaloids Alkaloids Cytotoxic activity |
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