Furostanol Saponins from the Bulbs of Welsh Onion, Allium fistulosum L.

Abstract

An extensive phytochemical analysis of the polar extracts from bulbs of Welsh onion Allium fistulosum L. led to the isolation of nine saponins, four of them, named fistulosaponins G (1a/1b), H (2), I (3a/3b), and J (4), have never been reported previously. Fistulosaponins G and I were isolated as a couple of isomers in equilibrium. On the basis of 2D NMR and mass spectrometry data, the structure of the novel compounds were elucidated as (25R)-26-[(β-D-glucopyranosyl)oxy]-3β,22β-dihydroxyfurost-5-en-1β-yl O-α-L-rhamnopyranosyl-(1 → 4)-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside (1a) with its 22α epimer (1b), (25R)-26-[(β-D-glucopyranosyl)oxy]-3β-hydroxyfurost-5,20-dien-1β-yl O-α-L-rhamnopyranosyl-(1 → 4)-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside (2), (25R)-26-[(β-D-glucopyranosyl)oxy]-3β,22β-dihydroxyfurost-5-en-1β-yl O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside (3a) with its 22α epimer (3b), and (25R)-26-[(β-D-glucopyranosyl)oxy]-3β-hydroxyfurost-5,20-dien-1β-yl O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside (4). This is the first report of furostanol saponins in A. fistulosum bulbs. In addition, data on the antibacterial tests of the isolated saponins against Escherichia coli and Enterococcus faecalis are reported.

Key words

Welsh onion - Allium fistulosum L. - Amaryllidaceae - furostanol saponins - fistulosaponins - NMR spectroscopy - antibacterial tests

• References

• 1 Stearn WT. Allium . In: Tutin TG, Heywood V, Burges N, Moore D, Valentine DH, Walters SM, Webb DA, eds. Flora Europea. Cambridge: Cambridge Press University; 1980: 64
• 2 Fritsch RM, Friesen N. Chapter 1: Evolution, Domestication, and Taxonomy. In: Rabinowitch HD, Currah L, eds. Allium Crop Science: recent Advances. Wallingford: CABI Publishing; 2002: 18
• 3 Li SZ. Compendium of Materia Medica. Bejing: Peopleʼs Medical Publishing House; 2004: 26-27
• 4 Institute of Materia Medica. Chinese medicine records. Bejing: Peopleʼs Medical Publishing House; 1984: 621-622
• 5 Do JC, Jung KY. Steroidal saponins from the subterranean part of Allium fistulosum . J Nat Prod 1992; 55: 168-173
• 6 Lai W, Wu Z, Lin H, Li T, Sun L, Chai Y, Chen W. Anti-ischemia steroidal saponins from the seeds of Allium fistulosum . J Nat Prod 2010; 73: 1053-1057
• 7 Lanzotti V, Barile E, Antignani V, Bonanomi G, Scala F. Antifungal saponins from bulbs of garlic, Allium sativum L. var. Voghiera. Phytochemistry 2012; 78: 126-134
• 8 Lanzotti V, Romano A, Lanzuise S, Bonanomi G, Scala F. Antifungal saponins from bulbs of white onion, Allium cepa L. Phytochemistry 2012; 74: 133-139
• 9 Zolfaghari B, Sadeghi M, Troiano R, Lanzotti V. Vavilosides A1/A2-B1/B2, new furostane glycosides from the bulbs of Allium vavilovii with cytotoxic activity. Bioorg Med Chem 2013; 21: 1905-1910
• 10 Barile E, Zolfaghari B, Sajjadi SE, Lanzotti V. Saponins of Allium elburzense . J Nat Prod 2004; 67: 2037-2042
• 11 Corea G, Fattorusso E, Lanzotti V. Saponins and flavonoids of Allium triquetrum . J Nat Prod 2003; 66: 1405-1411
• 12 Sadeghi M, Zolfaghari B, Senatore M, Lanzotti V. Spirostane, furostane and cholestane saponins from persian leek with antifungal activity. Food Chem 2013; 141: 1512-1521
• 13 Lanzotti V, Bonanomi G, Scala F. What makes Allium species effective against pathogenic microbes?. Phytochem Rev 2013; 12: 751-772
• 14 Rezgui A, Mitaine-Offer AC, Pertuit D, Miyamoto T, Tanaka C, Delemasure S, Dutartre P, Lacaille-Dubois MA. Steroidal saponins from Dracaena marginata . Nat Prod Commun 2013; 8: 157-160
• 15 Napolitano A, Musashvili T, Perrone A, Pizza C, Kemertelidze E, Piacente S. Steroidal glycosides from Ruscus ponticus . Phytochemistry 2001; 72: 651-661
• 16 Fattorusso E, Iorizzi M, Lanzotti V, Taglialatela-Scafati O. Chemical composition of shallot (Allium ascalonicum Hort.). J Agric Food Chem 2002; 50: 5686-5690
• 17 Dong M, Feng X, Wang B, Wu L, Ikejima T. Two novel furostanol saponins from the rhizomes of Dioscorea panthaica Prain et Burkill and their cytotoxic activity. Tetrahedron 2001; 57: 501-506
• 18 Agrawal PK, Jain DC, Gupta RK, Thakur RS. Carbon-13 NMR spectroscopy of steroidal sapogenins and steroidal saponins. Phytochemistry 1985; 24: 2479-2496
• 19 Kasai E, Ohikara M, Asakawa J, Mizutani K, Tanaka O. ¹³C NMR study of alpha- and beta-anomeric pairs of D-mannopyranosides and L-rhamnopyranosides. Tetrahedron 1979; 35: 1427-1432
• 20 Bokaeian M, Farazmand R, Kyghobadi S, Saeidi S. Study of the antimicrobial activity of Allium sativum extract on Staphylococcus aureus strains resistant to different antibiotics. J Plant Res 2015; 28: 34-40