Isoflavonoid production by adventitious-root cultures of Iris germanica (Iridaceae)

Abstract

We established the adventitious-root cultures of Iris germanica, a monocotyledonous plant known for isoflavonoid production. Irigenin (5,7,3Ј-trihydroxy-6,4Ј,5Ј-trimethoxyisoflavone) and iristectorigenin A (5,7,3Ј-trihydroxy-6,4Ј-dimethoxyisoflavone) along with their 7-O-b-D-glucosides, iridin and iristectorin A, respectively, were found as the major components in adventitious roots in the liquid medium, and the total isoflavone content was about 3.6 mmol per g fresh weight in 3-week-old cultures, which was much higher than the 0.7 mmol per g dry weight in the rhizome previously reported (Ali et al. 1983 Phytochemistry 22: 2061. Abiotic stress was applied by addition of 3 mM cupric chloride (CuCl 2 ) to the liquid medium. The isoflavone glucoside content was increased during the initial 6 h of CuCl 2 treatment, which was followed by a decrease; the aglycone level continued to increase throughout the 48 h of treatment. The decrease in glucoside content was negatively correlated with the increase in aglycone content between 6 and 48 h. The total isoflavone content (glucosidesϩaglycones) at 6 h after the start of CuCl 2 treatment was 1.4-fold the initial value, and nearly the same content was maintained for 48 h. Thus, the main effect of CuCl 2 treatment appeared to be the induction of hydrolysis of isoflavone glucosides. A cDNA of chalcone synthase was cloned, and the mRNA was expressed in the culture producing isoflavones.

New Constituents from the Rhizomes of Egyptian Iris germanica L.

“…A root decoction of the plant has been used as an antispasmodic, anti-inflammatory, emmengogue, stimulants, diuretic, aperients, and violently cathartic [11,12,15]. Iris germanica is considered as a rich source of secondary metabolites such as flavonoids [9,11,12,13,14,16,17,18,19,20], triterpenes [4,8,21,22,23,24,25,26], benzene and benzoquinones derivatives [15,19]. This article reports the isolation and characterization of two new compounds—irigenin S ( 7 ) and iriside A ( 12 )—along with ten known compounds: stigmasterol ( 1 ) [27], α-irone ( 2 ) [23], γ-irone ( 3 ) [23], 3-hydroxy-5-methoxyacetophenone ( 4 ) [28], irilone ( 5 ) [17,29,30], irisolidone ( 6 ) [15,17,31], irigenin ( 8 ) [16,17,32], stigmasterol-3- O - β - D -glucopyranoside ( 9 ) [33], irilone 4'- O - β - D -glucopyranoside ( 10 ) [14] and iridin ( 11 ) [15,17,34] (Figure 1) from the rhizomes of I. germanica L. growing in Egypt, the antimicrobial activity of its methanolic extract, as well as anti-inflammatory activity of the methanolic extract and the isolated flavonoids.…”

Phytochemistry and Biological Activities of Iris Species Growing in Iraqi Kurdistan and Phenolic Constituents of the Traditional Plant Iris postii

“…Iris isoflavonoids include germanaism A ( 1 ) [ 15 , 33 , 34 ], B ( 2 ) [ 15 , 17 , 33 , 34 ], C ( 3 ) [ 17 ], D ( 4 ) [ 17 ], E ( 5 ) [ 15 , 17 ], F ( 6 ) [ 17 ], G ( 7 ) [ 17 ], and H ( 8 ) [ 34 ], tectoridin ( 9 ) [ 35 , 36 ], iridin ( 10 ) [ 15 , 24 , 33 , 35 , 37 , 38 , 39 , 40 ], iridin A ( 11 ) [ 40 ], and S ( 12 ) [ 38 , 40 , 41 ], iristectorin A ( 13 ) [ 39 ], irisolidone-7- O -β- d -glucopyranoside ( 14 ) [ 15 , 37 , 42 ], 5,3′-dihydroxy-4′,5′-dimethoxyisoflavone 7- O -glucoside ( 15 ) [ 37 ], homotectoridin ( 16 ) [ 36 ], irilone ( 17 ) [ 14 , 15 , 24 , 34 , 38 , 40 , 42 , 43 ,…”

Going Back To The Roots

“…Additionally, previously published phytochemical studies, especially of iris in particular, were consulted to select a solvent. Conveniently, methanol and ethanol were used in a number of phytochemical studies (Akashi et al, 2005;Ali et al, 1983;Ibrahim et al, 2012;Kukula-koch et al, 2015;Rahman et al, 2003;Roger et al, 2010;Schütz et al, 2011;Wollenweber et al, 2003), as both are relatively non-toxic and widely…”

“…In accordance with a number of iris studies (Akashi et al, 2005;Ali et al, 1983;Ibrahim et al, 2012;Kukula-koch et al, 2015;Rahman et al, 2003;Wollenweber et al, 2003), methanol (MeOH) was also investigated as a maceration solvent. Having determined from the ethanol macerations that less than one day is not sufficient for full maceration, methanol macerations were conducted (again with 1 g orris, 3 mL 100% MeOH, at room temperature) for one day and four days, to determine if the different solvent benefited from extra maceration time.…”

“…Isoflavonoids are a class of molecules built off of a few variously-substituted versions of the 3phenylchromen-4-one backbone. Isoflavonoids are known in a range of plant genera, but a number of specific isoflavonoids are unique to the Iridaceae genus (Iris) (Akashi et al, 2005;Ali et al, 1983;Choudhary & Alam, 2017;Crisan & Cantor, 2016;Ibrahim et al, 2012;Kukula-koch et al, 2015;Mykhailenko, 2018;Rahman et al, 2003;Schütz et al, 2011;Wang et al, 2010;Wollenweber et al, 2003). The specificity of many of these compounds and relatively new research being done on them resulted in their absence from the NIST library that was used to identify compounds from the GC-MS data.…”