A phytochemical study of Allium hirtifolium Boiss flowers has led to the isolation of high amounts of six new furostanol and spirostanol saponins, named hirtifoliosides A1/A2 (1a/1b), B(2), C1/C2 (3a/3b), and D (4) along with three known spirostanol saponins, alliogenin 3-O-beta-D-glucopyranoside, gitogenin 3-O-beta-D-glucopyranosyl-(1 -> 4)-O-beta-D-glucopyranoside, and agapanthagenin 3-O-beta-D-glucopyranoside. High concentrations of the following known flavonol glycosides have been isolated from both flowers and bulbs: kaempferol 3-O-beta-D-rhamnopyranosyl-(1 -> 2)-glucopyranoside, kaempferol 3-O-beta-D-glucopyranosyl-(1 -> 4)-glucopyranoside, kaempferol 3-O-glucopyranoside, kaempferol 7-O-glucopyranoside. The isolated saponins along with the four saponins elburzensosides A1/A2 and C1/C2 and the sapogenin agapanthagenin, previously described from A. elburzense, have been subjected to biological assays for evaluating possible antispasmodic activity in the guinea-pig isolated ileum. The obtained results served as a basis for the establishment of structure-activity relationships within this class of antispasmodic agents. They highlight the positive effects of a hydroxyl group at position 5 and of a glucose unit at position 26 and demonstrate the detrimental effects of both a hydroxyl group at position 6 and of a glucose unit at position 3. Among the tested compounds, elburzensosides C1/C2 and agapanthagenin showed the highest activity in reducing induced contractions as measured by the reduction of histamine release by about 50%. The observed effect therefore contributes to the explanation of the traditional use of onion and garlic in the treatment of disturbances of the gastrointestinal tract.
Structure-activity relationships for Saponins from Allium hirtifolium and Allium elburzense and their antispasmodic activity / E., Barile; Capasso, Raffaele; Izzo, ANGELO ANTONIO; Lanzotti, Virginia; S. E., Sajjadi; B., Zolfaghari. - In: PLANTA MEDICA. - ISSN 0032-0943. - ELETTRONICO. - 71:(2005), pp. 1010-1018. [10.1055/s-2005-873134]
Structure-activity relationships for Saponins from Allium hirtifolium and Allium elburzense and their antispasmodic activity
CAPASSO, RAFFAELE;IZZO, ANGELO ANTONIO;LANZOTTI, VIRGINIA;
2005
Abstract
A phytochemical study of Allium hirtifolium Boiss flowers has led to the isolation of high amounts of six new furostanol and spirostanol saponins, named hirtifoliosides A1/A2 (1a/1b), B(2), C1/C2 (3a/3b), and D (4) along with three known spirostanol saponins, alliogenin 3-O-beta-D-glucopyranoside, gitogenin 3-O-beta-D-glucopyranosyl-(1 -> 4)-O-beta-D-glucopyranoside, and agapanthagenin 3-O-beta-D-glucopyranoside. High concentrations of the following known flavonol glycosides have been isolated from both flowers and bulbs: kaempferol 3-O-beta-D-rhamnopyranosyl-(1 -> 2)-glucopyranoside, kaempferol 3-O-beta-D-glucopyranosyl-(1 -> 4)-glucopyranoside, kaempferol 3-O-glucopyranoside, kaempferol 7-O-glucopyranoside. The isolated saponins along with the four saponins elburzensosides A1/A2 and C1/C2 and the sapogenin agapanthagenin, previously described from A. elburzense, have been subjected to biological assays for evaluating possible antispasmodic activity in the guinea-pig isolated ileum. The obtained results served as a basis for the establishment of structure-activity relationships within this class of antispasmodic agents. They highlight the positive effects of a hydroxyl group at position 5 and of a glucose unit at position 26 and demonstrate the detrimental effects of both a hydroxyl group at position 6 and of a glucose unit at position 3. Among the tested compounds, elburzensosides C1/C2 and agapanthagenin showed the highest activity in reducing induced contractions as measured by the reduction of histamine release by about 50%. The observed effect therefore contributes to the explanation of the traditional use of onion and garlic in the treatment of disturbances of the gastrointestinal tract.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.