title: 8-Hydroxyirilone 5-methyl ether and 8-hydroxyirilone, new antioxidant and α-amylase inhibitors isoflavonoids from Iris germanica rhizomes.
abstract: Iris species are well recognized as wealthy sources of isoflavonoids. In the present study, phytochemical investigation of the rhizomes of Iris germanica (Iridaceae) procure the isolation of two new isoflavonoids namely, 8-hydroxyirilone 5-methyl ether (2) and 8-hydroxyirilone (3), along with eight known isoflavonoids: irilone 4'-methyl ether (1), irilone (4), irisolidone (5), irigenin S (6), irigenin (7), irilone 4'-O-β-d-glucopyranoside (8), iridin S (9), and iridin (10). The isolated flavonoids were structurally characterized with the assist of comprehensive spectroscopic analyses (UV, IR, 1D and 2D NMR, and HRMS) and comparing with the published data. They were estimated for their antioxidant and antidaibetic capacities using DPPH and α-amylase inhibition assays, respectively. Compounds 2, 3, and 4 exhibited prominent antioxidant activities with IC50values of 12.92, 9.23, and 10.46μM, respectively compared to propyl gallate (IC507.11μM). Moreover, 2-5 possessed highest α-amylase inhibitory activity with % inhibition 66.1, 78.3, 67.3, and 70.1, respectively in comparison to acarbose (reference α-amylase inhibitor). Additionally, their structure-activity relationship has been discussed.
authors.affiliation: Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah Al Munawwarah 30078, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt. Electronic address: sribrahim@taibahu.edu.sa.
authors.forename: Sabrin R M
authors.initials: SR
authors.lastname: Ibrahim
authors.affiliation: Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, 71524 Assiut, Egypt.
authors.forename: Gamal A
authors.initials: GA
authors.lastname: Mohamed
authors.affiliation: Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah Al Munawwarah 30078, Saudi Arabia; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt.
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Zayed
authors.affiliation: National Center for Natural Products Research, Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, MS 38677, USA.
authors.forename: Samir A
authors.initials: SA
authors.lastname: Ross
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D031323:Iris Plant / Q000737:chemistry*; D007529:Isoflavones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D008738:Methyl Ethers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D027343:Rhizome / Q000737:chemistry*; D013329:Structure-Activity Relationship; D000516:alpha-Amylases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D007529:Isoflavones; D008738:Methyl Ethers; C530234:irilone; D000516:alpha-Amylases
keywords: 8-Hydroxyirilone; 8-Hydroxyirilone 5-methyl ether; Antioxidant; Iridaceae; Iris germanica; Isoflavonoid; α-Amylase inhibitors