Total Synthesis of Dispyrin, Purpurealidin E, and Aplysamine-1

Abstract

Bromotyrosine alkaloids dispyrin (1), purpurealidin E (2), and aplysamine-1 (3) isolated from marine sponge, were synthesized from commercially available tyramine (4) as a common starting material. The overall yield was 18%, 39%, and 22% for 1 from 4 in 5 steps, 2 in 5 steps, and 3 in 6 steps, respectively.

Synthesis of novel purpurealidin analogs and evaluation of their effect on the cancer-relevant potassium channel KV10.1

“…Synthesis of the simplified purpurealidin analogs was based on the amide coupling of purpurealidin E 4 or tyramine derivative 11 with aromatic carboxylic acids. Purpurealidin E 4 and 11 were synthesized in four steps from tyramine in an overall yield of 80% and 82%, respectively, improving the literature yields ( Fig 2 ) [ 4 , 13 , 14 ]. The synthetic route started with the bromination of tyramine.…”

Marine natural products

“…395 Dispyrin (Agelas dispar) 459 and purpurealidin (Psammaplysilla purpurea) 460 were synthesised from tyramine. 461 In a separate synthetic study, dispyrin was found to be a potent ligand and antagonist of a 1D and a 2A adrenergic and H2 and H3 histamine receptors. 462 Aplysamine 6 440, obtained from a Pseudoceratina sp.…”

Total Synthesis of the Marine Bromotyrosine Alkaloid Moloka'iakitamide

“…Introduction of a bromine atom at 5 was carried out by reported method in 2 steps. 15) Di-brominated phenol (6) was treated with iodide (8), which was prepared from N-(3-hydroxyproyl)phthalimide (7), 18) in the presence of potassium carbonate (K 2 CO 3 ) and benzyltriethylammonium chloride (BTAC) provided ether (9) in high yields (Chart 2).…”

“…IR spectra were recorded on a JASCO FT/IR-6300 spectrophotometer; ATRϭattenuated total reflectance system. NMR spectra were recorded on a JEOL JNM-ECX400 ( 15,18) Synthesis of Ether (9) A mixture of phenol (6) (410 mg, 1.04 mmol), iodide (8) (325 mg, 1.03 mmol), BTAC (24 mg, 0.105 mmol), and K 2 CO 3 (290 mg, 2.10 mmol) in CH 3 CN (6.0 ml) was stirred at rt for 48 h. The reaction mixture was poured into water, and extracted with AcOEt. The organic layer was washed with water and brine, dried over Na 2 SO 4 , and evaporated.…”

“…Because of these interesting activities, a number of synthetic studies on these alkaloids have been reported. [6][7][8][9][10][11][12][13][14][15][16] Moloka'iakitamide (1) 17) has been isolated from the Red Sea sponge Pseudoceratina arabica (Pseudoceratinidae) and shows significant parasympatholytic effects on isolated rabbit heart and jejunum, and weakly antifungal activity, contains one bromotyrosine unit and oxalamide moiety (Fig. 1).…”