Characterisation and quantification of flavonoids in Iris germanica L. and Iris pallida Lam. resinoids from Morocco.
BACKGROUND
Iris resinoid obtained from Iris germanica or Iris pallida rhizomes is widely used in the perfume industry but its chemical composition has not yet been reported. Nevertheless, very active compounds have been identified in iris rhizomes including iridals and isoflavones.


OBJECTIVE
In this first study concerning iris resinoid composition, flavonoids were qualitatively and quantitatively investigated in I. germanica and I. pallida resinoids.


METHODS
Resinoids were first fractionated by reverse-phase flash chromatography in order to obtain fractions containing all isoflavones. These fractions were analysed by HPLC-DAD (diode array detector) and the fractions containing isoflavones were analysed by HPLC-QTOF (quadrupole time of flight)-MS. Then, the main isoflavones were isolated and identified by NMR and high-resolution mass spectroscopy (HRMS). Finally, total and individual isoflavones were quantified by HPLC-DAD at 265 nm using an external calibration method with irigenin as the external standard.


RESULTS
Eight isoflavones were identified in both resinoids (irigenin, iristectorigenin A, nigricin, nigricanin, irisflorentin, iriskumaonin methyl ether, irilone, iriflogenin), one isoflavone only was identified in I. germanica resinoid (irisolidone), whereas one isoflavone (8-hydroxyirigenin), one isoflavanone (2,3-dihydroirigenin) and one benzophenone (2,6,4'-trihydroxy-4-methoxybenzophenone) only were identified in I. pallida resinoid. Isoflavones were quantified in I. germanica and I. pallida resinoids at 180 ± 1.6 mg/g and 120 ± 3.3 mg/g respectively.


CONCLUSIONS
The study shows that I. germanica and I. pallida resinoids are rich in flavonoids and that these two Iris species can be distinguished by simply analysing the polyphenol fraction.
Société Phytotagante, 9 Boulevard de Clairfont, 66350 Toulouges, France.
B
B
Roger
V
V
Jeannot
X
X
Fernandez
S
S
Cerantola
J
J
Chahboun
D001577:Benzophenones / Q000737:chemistry / Q000302:isolation & purification; D005591:Chemical Fractionation / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D031323:Iris Plant / Q000737:chemistry*; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D009018:Morocco; D027343:Rhizome / Q000737:chemistry*; D013045:Species Specificity
D001577:Benzophenones; D005419:Flavonoids; D007529:Isoflavones; C530234:irilone; C570745:irisflorentin; C509874:irigenin; C569021:4-methoxybenzophenone