RESUMEN
Fifteen bromotyrosine-derived alkaloids were isolated from the sponge Pseudoceratina cf. purpurea. The acetylcholinesterase-inhibiting activity of all the isolated compounds were examined; to purealidin Q, isoanomoian A, aplyzanzine A, and aplysamine 2 were active with IC50 values of 1.2, 70, 104, and 1.3 µM, respectively. On the other hand, antiproliferative activity against MCF-7 cells of aerophobin 1 gave an IC50 value of 0.8 µM. The Michaelis-Menten plots of the active alkaloids indicated that all the four compounds inhibited acetylcholinesterase in a non-competitive manner. The structures of the active compounds suggested that the N,N-dimethylaminopropyloxydibromotyramine moiety may play an important role in the enzyme-inhibiting activity, presumably on the anionic and hydrophobic binding sites.
Asunto(s)
Acetilcolinesterasa/metabolismo , Alcaloides/química , Alcaloides/farmacología , Inhibidores de la Colinesterasa/química , Tirosina/análogos & derivados , Proliferación Celular/efectos de los fármacos , Inhibidores de la Colinesterasa/farmacología , Activación Enzimática/efectos de los fármacos , Humanos , Células MCF-7 , Estructura Molecular , Tirosina/química , Tirosina/farmacologíaRESUMEN
The composition of the essential oil of the leaves of Tetrapleura tetraptera (Schum. & Thonn.) Taubert. from Nigeria were analyzed by GC/MS. Forty-one compounds representing 89.5% of the essential oil were characterized. The essential oil was dominated by 1,8-cineole (19.4%), 6,10,14-trimethyl-2-pentadecanone (13.6%), phytol (9.1%), alpha-pinene (8.1%) and geranylacetone (6.7%). The oil exhibited moderate toxicity in the brine shrimp lethality assay (117.5 microg/mL), and displayed weak antibacterial activity against Bacillus subtilis.