RESUMO
Plants of the Amaryllidaceae family are well-known (not only) for their ornamental value but also for the alkaloids that they produce. In this report, the first phytochemical study of Clinanthus genus was carried out. The chemical composition of alkaloid fractions from Clinanthus microstephium was analyzed by GC/MS and NMR. Seven known compounds belonging to three structural types of Amaryllidaceae alkaloids were identified. An epimeric mixture of a haemanthamine-type compound (6-hydroxymaritidine) was tested as an inhibitor against acetyl- and butyrylcholinesterase enzymes (AChE and BChE, respectively), two enzymes relevant in the treatment of Alzheimer's disease, with good results. Structure-activity relationships through molecular docking studies with this alkaloid and other structurally related compounds were discussed.
Assuntos
Alcaloides/química , Alcaloides de Amaryllidaceae/química , Amaryllidaceae/química , Inibidores da Colinesterase/química , Fenantridinas/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Alcaloides/metabolismo , Alcaloides/farmacologia , Amaryllidaceae/metabolismo , Sítios de Ligação , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Relação Estrutura-AtividadeRESUMO
Clinanthus milagroanthus S. Leiva & Meerow, sp. nov. is described from the Department of La Libertad in Peru. The new species is most closely related to Clinanthus mirabilis (Ravenna) Meerow, with further affinities to Clinanthus viridiflorus (R. & P.) Meerow. It can be distinguished from Clinanthus mirabilis by its wider leaves, the much more brightly colored and wide spreading limb, and the much lighter colored perigone tube (yellowish green vs. dark green in Clinanthus mirabilis). A conspicuous bulge just proximal to the midpoint of the tube is a unique character of the new species.
ResumenClinanthus milagroanthus S. Leiva & Meerow, sp. nov. se describe desde el Departamento de La Libertad, Perú. La nueva especie es más estrechamente relacionada con Clinanthus mirabilis (Ravenna) Meerow, con adicionales afinidades con Clinanthus viridiflorus (R. & P.) Meerow. Se puede distinguir de Clinanthus mirabilis por sus hojas más anchas, el limbo mucho más amplio de colores brillantes, y el color de tubo perigonio mucho más claro (color amarillento vs. verde verde oscuro en Clinanthus mirabilis). Una protuberancia visible casi proximal al punto medio del tubo es un carácter único de la nueva especie.