We have investigated the flavonoid composition of the epigeal part of Halocnemum strobilaceum, ram. Chenopodiaceae, gathered in the dried up bed of the Aral Sea in the flowering phase.It was found that this plant contained 31.0% of extractive substances. A quantitative determination of the total fiavon~ds was made by the phctceleoroedorim~ric method. According to a calibration graph it amounted to 1.2%, calculated as turin [ 1 ]. To obtain the total flavonoids, the air-dry raw material (500.0 g) was extracted first with benzene to eliminate lipc0dlic substances, and then with aqueous ethanol. The aqueous alcohofic extract, concentrated to an aqueous residue, was ueated with ethyl acetate. The ethyl acetate extract, concentrated to minimal volume, was deposited on a column of polyamide sorbent and was eluted with water and alcohol at various concentrations.The following flavonoids and flavonoid glycosides were isolated:Substance (1) -- C21H2oO12, mp 237--240~ (from MeOH), [a]v 2~ -62.2 ~ (c 0.1; ethanol); Xm~(C2HsOH) 362, 255 tun -- quercetin 3-O-[l-D-glucopyranoside, or isoquercitrin [2].Substance (2) -- C22H22Ot2, mp 220---222~ (from MeOH), [aid 22 -54 ~ (c 0.335, ethanol); Xmx(C2HsOH) 256, 275 (sh), 367 nm -- isorhamnetin 3-O-~-D-glucopyranoside.Substance (3) -- Ci6Hl207 mp 305~ (from MeOH), Xma~(C2H5OH) 254, 278 (sh), 370 nm -- isorhamnetin [3].Substance (4) -- C17H1407, mp 214 216~ (from (MeOH), Xm,x(C2HsOH) 254, 374 nm -- rhamnazin.Substance (5) -- C22H23012 N, mp 241--243~ (from MeOH), [a]D 22 +89 ~ (c 0.4; ethanol); [M]a.K,+219. ~m(C2HsOFL nm) 360, 256 (sh), 265; + CH3COONa: 362, 255 (sh), 266; + H3BO 3 + CH3COONa: 360, 254 (sh), 264; + C2H5ONa: 392, 254 (sh), 270; + AIC13: 405, 257 (sh), 270; + AICI 3 + HCI: 380, 256 (sh), 268. Vm~ (KBr, cm-t: 3600---3400 (OH); 2940 (OCH3) , deformation vibrations: 1610 (N--H), 1100~1000 (three peaks), 840 (a-configuration of a glycosidic bond).Acid hydrolysis (2% HCI, 2 h) formed isorhamnetin with mp 350~To determine the sugar fragment, the aqueous residue obtained after acid hydrolysis was concentrated and purified chromatographically. With the o-toluidine reagent the sugar gave a blue-green coloration, and with ninhydrin a violet-red coloration.The sugar formed white crystals with mp 82--84~ PMR spectrum (D20 + DSS), ppm: 4.15 (d, H-I', J = 2 Hz); 4.02 (d, H-2'); 3.85--3.81 (m, H-3'); 3.64 (m, H-4'); 3.42 (2H-5'). In the 14N spectrum of the sugar a signal of amine nitrogen was observed in the 329.302 ppm region Consequently this sugar residue was that of an amino sugar -- namely, glucosamine [4].UV and IR spectroscopies showed that the aminosugar was attached in the C-7 position and had the pyranose form and the a-configuration of the glycosidic bond in the molecule of the monoglycoside.Thus, on the basis of chemical and spectral analyses, for substance (5) we propose the structure of 3,4',5-trihydroxy-3' methoxyflavone 7-O-a-D-glucosaminopyranoside.