Montbresides A–D: antibacterial p-coumaroyl esters of a new sucrose-based tetrasaccharide from Crocosmia × crocosmiiflora (montbretia) flowers

Crocosmia × crocosmiiflora (montbretia) flowers yielded four esters (montbresides A–D) of a new sucrose-based tetrasaccharide, 3-O-β-d-glucopyranosyl-4´-O-α-d-rhamnopyranosyl-sucrose [β-d-Glc-(1 → 3)-α-d-Glc-(1↔2)-β-d-Fru-(4 ← 1)-α-d-Rha]. All four possess O-p-coumaroyl residues on C-3 of fructose and C-4 of α-glucose, plus O-acetyl residues on C-2 and C-3 of rhamnose and C-6 of fructose. Montbresides A and B are additionally O-acetylated on C-1...