Leonurine

Leonurine is an alkaloid isolated from Herba leonuri, with anti-oxidative and anti-inflammatory.

Leonurine is a trihydroxybenzoic acid.

To a stirred solution of compound 2 (5.6g, 20mmol) in DMF (15mL) was added S-methylisothiourea hemisulfate (3) (15percent in water, 23.1g, 25mmol), the mixture was heated to reflux and stirred at 120°C for 6h. HPLC indicated the disappearance of starting material, the solvent was removed in vacuo and the residue was dissolved in water. NaHCO(15mL) in the step (3) obtained motherwort amine (5.6g, 20mmol) was added DMF, then add methylisothiourea sulfate (15percent aqueous solution, 23.1g, 25mmol), was heated to 120 reaction 6h.HPLC detection reaction, complete disappearance of starting material, out of the solvent under reduced pressure, dissolved in water, to which was added sodium hydrogencarbonate (2.31g, 27.5mmol) and, a large number of the solid, the solid product was recovered by filtration to give a white solid product, that is the final product leonurine (4.0g), the structural formula as shown in formula VI.Take the mother herb (11g) dissolved150 mL of DMF was addedS-methylisothiourea sulfuric acid (50 g) was added to the mixture140 , reaction 5h, TLC tracking. Recovery solvent, add sodium chloride aqueous solution for salting out, and then alkalized with sodium bicarbonate, immediately a large number of crystal precipitation, put the refrigerator, filter ash to get purple crystal. The crystals were recrystallized from methanol to give 17 g of white crystals having a melting point of 214-215 ° C.Take the mother herb (11g) dissolved150 mL of DMF was addedS-methylisothiourea sulfuric acid (50 g) was added to the mixture140 , reaction 5h, TLC tracking. Recovery solvent, add sodium chloride aqueous solution for salting out, and then alkalized with sodium bicarbonate, immediately a large number of crystal precipitation, put the refrigerator, filter ash to get purple crystal. The crystals were recrystallized from methanol to give 17 g of white crystals having a melting point of 214-215 C.To a stirred solution of compound 2 (5.6g, 20mmol) in DMF (15mL) was added S-methylisothiourea hemisulfate (3) (15% in water, 23.1g, 25mmol), the mixture was heated to reflux and stirred at 120C for 6h. HPLC indicated the disappearance of starting material, the solvent was removed in vacuo and the residue was dissolved in water. NaHCO3 (2.31g, 27.5mmol) was added and lots of solid began to appear as the mixture stirring. The solid was collected by filtration and dried to give Leonurine (1) (4.0g, 65% yield) as a white solid. 1H NMR (400MHz, CF3COOD): delta 7.38 (s, 2H), 4.42 (t, 2H, J=6.2Hz), 3.91 (s, 6H), 3.30 (t, 2H, J=6.7Hz), 1.89 (dt, 2H, J=13.3, 6.5Hz), 1.83-1.71 (m, 2H). lit. [18] 1H NMR (400MHz, CF3COOD): delta 7.36 (s, 2H), 4.3'4.55 (br, 2H), 3.94 (s, 6H), 3.15'3.45 (br, 2H), 1.75'2.05 (br, 4H).(15mL) in the step (3) obtained motherwort amine (5.6g, 20mmol) was added DMF, then add methylisothiourea sulfate (15% aqueous solution, 23.1g, 25mmol), was heated to 120 reaction 6h.HPLC detection reaction, complete disappearance of starting material, out of the solvent under reduced pressure, dissolved in water, to which was added sodium hydrogencarbonate (2.31g, 27.5mmol) and, a large number of the solid, the solid product was recovered by filtration to give a white solid product, that is the final product leonurine (4.0g), the structural formula as shown in formula VI.

Molecular Weight:311.33
XLogP3:0.5
Hydrogen Bond Donor Count:3
Hydrogen Bond Acceptor Count:6
Rotatable Bond Count:9
Exact Mass:311.14812078
Monoisotopic Mass:311.14812078
Topological Polar Surface Area:129
Heavy Atom Count:22
Complexity:360
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes