M. P. Yuldashev

The total flavonoids fromThermopsis alterniflora, Th. dolichocarpa, Vexibia alopecuroides, andRhaponticum carthamoides and their hypolipidemic activity

The total flavonoids have been isolated from the epigeal part ofThermopsis alterniflora andTh. dolichocarpa, and the roots and rhizomes ofVexibia alopecuroides, andRhaponticum carthamoides the compositions of the flavonoids present in each of the total extracts have been determined. It was found that the total flavonoid extracts investigated exhibited different degrees of hypolipidemic activity in relation to normal animals and animals with experimental hyperlipidemias. The total flavonoids fromTh. alterniflora possessed the most pronounced hyperlipidemic action.

Structures of two new flavonoids fromScutellaria ramosissima

The new 2(S)-2′,5-dihydroxy-7-β-D-glucopyranosyloxyflavanone has been isolated from the epigeal part ofScutellaria ramosissima M. Pop. Oroxylin A, woganin, 2′,6′-trihydroxy-6,7,8-trimethoxyflavone, and vanillic and syringic acids, and also the new substance 5,6-dihydroxy-7,8-dimethoxyflavone, have been isolated from the roots of this plant for the first time. The structures of the flavonoids isolated have been established on the basis of chemical transformations and spectral characteristics.

Flavonoids of Thermopsis alterniflora

From the epigeal part ofThermopsis alterniflora Rgl.et Schmalh. (Fabaceae), in addition to formononetin, ononin, cynaroside, and rothindin, two new acylated flavone glycosides have been isolated and, on the basis of chemical transformations and spectral characteristics, their structures have been established as 4′,5,7-trihydroxy-3′-methoxyflavone 7-O-(6″-O-crotonoyl-β-D-glucopyranoside) and 4′,5,7-trihydroxyflavone 7-O-(6″-O-crotonoyl-β-D-glucopyranoside).

Flavonoids ofCaragana alaica

A new isoflavonglycoside is isolated from the terrestrial part ofCaragana alaica A. Pojark in addition to the known flavonoids 3-O-α-L-rhamnopyrano- and 3-O-β-D-glucopyranosides of isorhamnetin, quercetin, and vistin. The structure 3′-hydroxy-6.4′-dimethoxy-7-O-β-D-glucopyranosylisoflavone is established on the basis of chemical and spectral data.

Flavonoids of the epigeal part of Kickxia elatine

From the epigeal part of Kickxiaelatine (L.) Dumort we have isolated demethoxycentaureidin 7-O-β-D-glucoside, pectolinarin, and acetylpectolinarin, and the new flavone glycoside demethoxycentaureidin 7-O-rutinoside, the structure of which was established on the basis of chemical transformations and spectral characteristics.

Flavonoids of Thermopsis dolichocarpa.

The air-dry comminuted raw material (2.6 kg) was exhaustively extracted with 85% ethanol. The extract was evaporated in vacuum, the residue was dissolved in water, and the solution was shaken successively with chloroform and with ethyl acetate. The ethyl acetate extract was evaporated and the residue (33.0 g) was treated with boiling aqueous ethanol. After cooling, the precipitate that had deposited was filtered off and the mother solution was evaporated in vacuum. By chromatography on a silica gel column in a chloroform-methanol gradient system the residue from the mother liquor yielded flavonoids (I-III), while the precipitate gave flavonoids (IV) and (V).

Flavonoids of the epigeal part of Scutellaria ramosissima

Chrysin 7-O-β-D-glucuronide and two new flavanones have been isolated from the epigeal part ofScutellaria ramosissima. It has been established on the basis of spectral characteristics and the results of chemical transformations that they have the structures of 2(S)-2′,5,7-trihydroxyflavanone 7-O-(methyl β-D-glucopyranosiduronate) and 2(S)-2′,5,7-trihydroxyflavanone 7-O-(ethyl β-D-glucopyranosiduronate).

Interrelationships of the structures and antioxidant activities of some flavonoids from the plants of Central Asia

A study has been made of the influence 27 flavonoids on the processes involved in the peroxide oxidation of lipids. The interrelationship between the chemical structures of isoflavones, flavones, flavanones, and flavonols and their antioxidant activities is discussed.

Flavonoids of some plants of the genusHaplophyllum

P. A. Hedin, P. L. Lamar, A. C. Thompson, and J. P. Minyard, Am. J. Bot., 55, No. 4, 431 (1968). A. R. EI-Mandy and L. A. El-Sebaiy, Food Chem., 14, 237 (1984). L. K. Klyshev, V. A. Bandyukova, and L. S. Alyukina, Plant Flavonoids [in Russian], Alma-Ata (1978). F. G. Akhmedova and G. Sattarov, Tr. Tashkentsk. Farm. Inst., ~, 86 (1966). M. N. Zaprometov, Biochemical Methods of Plant Analysis [Russian translation], IL, Moscow (1960). R. L. Whistler and E. Conrad, J. Am. Chem. Soc., 76, 1673, 3544 (1954).

Flavonoids from Scutellaria cordifrons and S. phyllostachya roots

Plants of the genus Scutellaria L. (Lamiaceae) are rich sources of flavonoids, terpenoids, phenylpropanoids, and other biologically active compounds [1]. In continuation of research on flavonoids from plants of this genus, we studied roots of S. cordifrons Juz. and S. phyllostachya Juz. [2]. Baikalein, 5,7-dihydroxy-2 ′-methoxyflavone, and chrysin have previously been isolated from roots of S. phyllostachya [3]. The flavonoid composition of S. cordifrons has not previously been studied. Ground air-dried roots (1 kg) of S. cordifrons were collected at the end of vegetation (November 2000) near the village Chodak of Namangan District of the Republic of Uzbekistan and were exhaustively extracted with ethanol. The ethanol extract was condensed in vacuo, diluted with water, and extracted successively with hexane, chloroform, and ethylacetate. Chromatography of the CHCl 3 fraction (20.0 g) over a silica-gel column with gradient elution by CHCl 3:propan-2-ol isolated 1 and 2, which were also isolated from the CHCl 3 extract of the alcohol extract of S. phyllostachya (raw material collected in November 2000 near the village Mamai of Yangikurgan Region of Namangan District). Flavonoid 1, C18H18O7, mp 220-221°C (dec.). The UV spectrum (EtOH, λmax, 242 sh, 290, 346 nm) was characteristic of flavanone derivatives [4]. The IR spectrum of 1 contained absorption bands for hydroxyl (3200, 3450 cm -1), ethoxyls (2930), pyrone carbonyl (1650), and aromatic C=C (1615, 1590). The mass spectrum exhibited peaks for ions with m/z 346 [M] +, 328 [M H2O], 313 (100) [M H2O CH3], 285, 197, 196, 181, 168, 153. The PMR spectrum (DMSO-d 6, ppm, J/Hz) had signals for protons at 2.52 (1H, dd, J = 17.5, 3.2, H-3 eq), .65, 3.76, 3.83 (each 3H, s, 3 × OCH 3), 3.95 (1H, dd, J = 17.5, 13.5, H-3ax), 5.96 (1H, dd, J = 13.5, 3.2, H-2), 6.22 (1H, s, H-8), 6.51 (2H, br. d, J = 8.5, H-3 ′, H-5′), 7.20 (1H, br. t, J = 8.5, H-4′), 9.90 (1H, s, 2-OH), 12.10 (1H, s, 5-OH). Based on PMR and mass spectral data, 1 contains three methoxyls and two hydroxyls. The mass spectral fragmentation is consistent with two methoxyls and one hydroxyl on ring A [5]. Comparison of the spectral data with those of an authentic sample of 1 identified it as (+)-5,2 ′-dihydroxy-6,7,6′-trimethoxyflavanone [6, 7]. Flavonoid 2, C19H20O8, mp 148-149°C, was a flavanone derivative according to its UV spectrum ( λmax 289, 359 nm) [4]. The IR spectrum contained absorption bands at 3450-3250, 2950, 1660, 1617, and 1578 cm -1. The ass spectrum of 2 had peaks for ions with m/z 376 [M] +, 358, 343, 315, 226, 211, 183, 131, 119, 83, and 69 (100). The PMR spectrum (DMSO-d6, J/Hz): 2.75 (1H, dd, J = 3.1, 17.5, H-3 eq), 3.16, 3.30, 3.43, 3.55 (each 3H, s, 4 × OCH 3), 3.75 (1H, dd, J = 3.1, 17.5, H-3ax), 5.95 (1H, dd, J = 13.5, 3.1, H-2), 6.52 (2H, br. d, J = 8.5, H-3 ′ 5′), 7.19 (1H, br. t, J = 8.5, H-4 ′), 11.90 (1H, s, 5-OH). The PMR and mass spectrum indicated that 2 differed from 1 by the presence of an additional methoxyl in the 8-position of the flavanone nucleus. Based on the data and a direct comparison with an authentic sample, 2 was identified as (-)-5,2 ′-dihydroxy6,7,8,6′-tetramethoxyflavanone [7, 8]. Flavonoids 1 and 2 were isolated for the first time from these Scutellaria species.