No abstract
In continuation of research on isoprenoids from plants of the genus Astragalus [1], we isolated from leaves of A. caucasicus Pall. (Leguminosae L.) compounds called cycloascaulosides A, B, and C. Herein the structure of cycloascauloside A is reported.The PMR spectrum of cycloascauloside A (1) contained two 1H doublets coupled in an AB-type system at 0.39-0.54 ppm with SSCC 2 J = 4.5 Hz in addition to signals for seven methyls at 0.80-1.78 ppm. This enabled 1 to be considered as a cycloartane triterpenoid [1][2][3]. This conclusion was confirmed by absorption bands in the IR spectrum at 3045 and 1452 cm -1 and the preparation of cyclogalegigenin (2) upon acid hydrolysis of 1 and its Smith decomposition [2][3][4]. The carbohydrate part of the hydrolysate contained D-glucose and L-rhamnose in a 1:1 ratio according to paper (PC) and gas chromatography [5]. 1: R = α-L-Rhap-(1→6)-β-D-(2-O-Ac)-Glcp 2: R = H 3: R = α-L-Rhap-(1→6)-β-D-Glcp 4: R = β-D-GlcpThe IR spectrum of 1 exhibited absorption bands at 1755 and 1240 cm -1 (ester); the PMR spectrum, a 3H singlet at 1.98 ppm belonging to an acetyl. As expected, the 13 C NMR spectrum of 1 contained signals for C atoms of one acetyl at 19.70 and 170.02 ppm.Glycoside 1 treated with dilute base solutions gave progenin 3, which underwent partial hydrolysis. The resulting products included cyclogalegigenin and glycoside 4, acid hydrolysis of which gave D-glucose and genin 2. Therefore, D-glucose was directly bound to cyclogalegigenin.
547.972In the leaves of Pueraria h/rsuta L. (Thunberg kudzu bean), faro. Leguminosae, growing in Georgia we have detected six flay,hold compounds derived from quercetin and kaempferol [1], including a flavonoid glycoside, robinin, from which the antiuremic drug flaronin has been created [2].The individual flavonoid (1) crystallized out from a chloroform-purified aqueous alcoholic extract. By extraction with ethyl acetate, the mother liquor remaining after the separation of this compound yielded the total flavonoids, from which the individual compounds (1)-(4) were isolated.Flay.hold (1) --mp 192-193"C; [Ct]D 2° --83.5* (c 0.1; ethanol-DMFA 99:1), ~maxC2H5 °H, rim: 355, 265. This was decomposed by acid into an aglycon --kaempferol, with nap 274-278"C, D-galactose and L-rhamnose. The yield of the aglyeon was 36 %. Substance (1) was identified as robinin [2]. Flavonoid (2) --mp 182-186"C; [OdD 2° -26.5* (c 0.5; DMSO), kmaxC2H5 °H nm: 363, 255. This was decomposed by acid into quercetin with nap 302-305"C, D-glucose, and L-rhamnose. Flavonoid (2) was characterized as rutin [3, 5]. Flay.hold (3) --mp 181-184"C; [tX]D 2° --32.5 ° (C 0.5; DMSO); hmax C2HS°H, nm: 352, 266. This was decomposed into kaempferol and rutinose. Substance (3) was identified as nicotiflorin [3, 4].Flay.hold (4) --mp 239-242°C; [OdD 2° -23.1" (c 0.52; DMSO), kmax CH3°H, nm: 250, 260 sh. Acid hydrolysis formed the aglycon daidzein with mp 320-322"C and D-glucose. Substance (4) proved to be the isoflavone daidzin [3].The amount of robinin in the leaves of P. hirsuta was 1.7 %, of which 1.4% was isolated by direct crystallization. The considerable raw material resources of P. h/rsuta in Georgia and its high robinin content permit this plant to be recommended as an additional source of the drug flaronin [5].
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