Diosmetin from

VI. Isolation of Diosmetin from Crude Apigenin and Its Identification as 5,7,3 -Trihydroxy-4 -methoxyflavone. 63... 

Fig. 2.85. Examples of chromatograms, (a) extract of 1ml blank plasma (b) plasma sample obtained from a female healthy subject 2h after oral administration of a Daflon tablet (diosmin/hesperidin, 450/50 mg) containing 61.2 ng/ml of diosmetin. Peaks I = internal standard, 7-ethoxycoumarin II = diosmetin. Reprinted with permission from F. I. Kanaze el al. [205].

Diosmetin. After v. Kostanecki and coworkers isolated true apigenin from crude apigenin and proved its identity with the syn-... 

Different extracts of Citrus were subjected to SPE on Cig cartridges to remove polar components. The retained flavonoids (mainly flavanones) were eluted with methanol-dimethyl sulfoxide, which enhanced solubility of hesperidin, diosmin, and diosmetin. Recoveries of eriocitrin, naringin, hesperidin, and tangeretin from spiked samples of mesocarp tissue exceeded 96%. Flavones were relatively abundant in the leaves. ... 

Series of cassiaoccidentalins built on a 6-C-(6-deoxy-ribo-hexos-3-ulosyl)flavone general structure, and isolated from Cassia — cassiaoccidentalin A 6-C-glycosyl 2 -0-rhamnosyl)apigenin B 6-C-glycosyl (2"-0-rhamnosyl)luteolin and C 6-C-glycosyl (2"-0-rhamnosyl)diosmetin. 

Substantial quantities of luteolin-7-O-glucuronide, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside occur in Red Oak Leaf and Lollo Rosso, two red-leaved varieties of lettuce (Lactuca sativa) [Llorach et al., 2008], Polymethoxylated flavones such as nobiletin, scutellarein, sinensetin, and tangeretin (Fig. 1.8) are found exclusively in citrus species [Crozier et al., 2006c], while diosmetin-7-O-glucuronide has been isolated from the fruits of a Chinese herb, Luffa cylindrical. 

Fig. 2 Separation of 25 flavonoid standards (1—eriocitrin 2— neoeriocitrin 3—robinetin 4—narirutin 5—naringin 6— rutin 7— hesperidin 8—neohesperidin 9—isorhoifolin 10— rhoifolin 11—diosmin 12—neodiosmin 13—neoponcirin 14—quercetin 15— poncirin 16—luteolin 17—kaempferol 18—apigenin 19—isorhamnetin 20—diosmetin 21— rhamnetin 22—isosakuranetin 23— sinensetin 24—acacetin 25—tangeretin) using Cig Lichrospher 100, 250 x 4.0 mm, 5 pm, Merck gradient elution with 0.01 M phosphoric acid-methanol with flow rate of 0.6 mL/min at 40°C and detection at 285 nm. (From Ref. [8].)...

In our first study with Salvia species, S. triloba L.f. [8] we have isolated a new flavone salvigenin (1) (6,7,4 -trimethylapigenin), later the same compound was obtained from other Salvia species. From S. tomentosa [9] cirsimaritin (2), jaceosidin (3), 5-hydroxy-6,7,3 ,4 -tetramethoxyflavone (4), 6-methoxyluteolin (5), luteolin (6), luteolin 7-glucoside (7) were isolated, in an other study with the same plant [10] further compounds eupatilin (8), cirsilineol (9), diosmetin (10), 6-hydroxyluteolin 7- and 5-glucosides (11 and 12) were obtained. 

Afanas ev et al. demonstrated the ability of rutin to form a stable complex with Fe2+ at physiological pH [142]. The absorption spectrum of the Fe2+-rutin complex did not change during 8 hours [142]. Morel et al. investigated radiochemically the capacity of three flavonoids (catechin, quercetin and diosmetin) and desferrioxamine - a powerful chelator of Fe3+ - to remove Fe3+ from iron-loaded hepatocytes [18, 143]. Nitrilotriacetic acid - a low affinity iron-chelator - was used to maintain Fe3+ in a soluble state. The iron-chelating ability decreased in the following order desferrioxamine > catechin > quercetin > diosmetin (which had a very low activity) [18, 143]. 

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