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1-Hydroxy-2,3,4,5-tetramethoxyxanthone, which is used as a standard for quantitative determination of the total content of γ-pyrones, was isolated from the aerial part of Halenia corniculata L. Cornaz., an available raw material in Russia. A method for preparing standard 1-hydroxy-2,3,4,5-tetramethoxyxanthone was developed.We previously proposed a method for quantitative determination of the total content of γ-pyrones in the aerial part of Halenia corniculata L. Cornaz. [1]. The standard sample in this method was 1-hydroxy-2,3,4,5-tetramethoxyxanthone (1), which is the dominant component of the xanthones in the aerial part of H. corniculata. Several methods for preparing 1 are known: from roots and the aerial part of Swertia bimaculata Hf. & T. in 0.003% yield [2]; from roots of Frasera caroliniensis Walt., in 0.07% yield [3]; and from roots and the aerial part of H. asclepidea (HBK) Don, H. elliptica D. Don, and H. campanulata in yields of 0.10, 0.12, and 0.13%, respectively [4-6].Drawbacks of these methods are the unavailability of the raw material, the low yields (0.003-0.13% per mass of absolute dry raw material), and the duration and labor-intensiveness of the process.The goal of the present work was to develop a method for preparing standard 1 from the aerial part of H. corniculata growing in Russia.Several methods for preparing 1 were studied during the course of the work. Method 1 produced 1 in 0.04% yield. Methods 2-4 under the same conditions but using different eluents for column chromatography also isolated 1 in yields of 0.25, 0.12, and 0.04%, respectively. Method 5 involves simultaneous extraction of raw material and hydrolysis by HCl (2%). The resulting product (0.02% yield) was contaminated with oleanolic acid, which interferes with the separation and preparation of 1 as a pure compound.Method 2 gave the highest yield of 1 from the aerial part of H. corniculata and was used to produce three batches of 1. The content of 1 as determined by HPLC was 95.31-96.87% (Fig. 1). The compounds were identified using TLC, melting points, and UV and PMR spectroscopies. The physicochemical properties of the final product were analogous to those of chemically pure 1.

T. M. Mikhailova, L. M. Tankhaeva, UDC 582.998+581.192 G. G. Nikolaeva, and S. M. NikolaevWe previously isolated and identified from leaves of Cacalia hastata polysaccharides [1], photosynthetic pigments [2], and organic acids [3]. Phenolic acids have been detected in leaves of C. hastata by investigating the ethylacetate fraction using HPLC (Milichrom A-02, Nucleosil 100-5, C18; 75 × 2 mm; 0.05 M KH 2 PO 4 :CH 3 CN, 95:5).Pure compounds were isolated by chromatographing over polyamide columns (40 × 200 mm) the ethylacetate fraction obtained by gradient extraction in a Soxhlet apparatus. Phenolic acids were eluted with water. Fractions were concentrated and rechromatographed on paper (PC) (FM-12, BuOH:AcOH:H 2 O, 10:8:7, system I; AcOH:H 2 O, 15:85, system II). Pure compounds were eluted by ethanol (50%). Recrystallization from ethanol produced three compounds. The purity of the isolated compounds was established using qualitative reactions, melting points, the lack of melting point depression in mixed samples, chromatographic mobility, alkaline destruction products, and UV analysis with diagnostic additives [4].Compound 1, mp 197-199°C (EtOH), PC R f 0.80 (system I), 0.52 (system II), UV spectrum (EtOH, λ max , nm): 328, 300, 230; (AcONa) 310, 278; (MeONa) 362, 251; (H 3 BO 3 +AcONa) 320, 297; (AlCl 3 ) 358, 310, 240. The alkaline destruction products contained a compound with mp 202-203°C that was chromatographically identical to protocatechuic acid, caffeic acid. Compound 2, mp 202-204°C (EtOH), PC R f 0.65 (system I), 0.62 (system II), UV spectrum (EtOH, λ max , nm): 328, 240; (AcONa) 330; (MeONa) 381, 260; (H 3 BO 3 ) 381, 260; (H 3 BO 3 ); (AlCl 3 ) 360, 215, 238. Alkaline hydrolysis produced caffeic and quinic acids [5]. Compound 2 is chlorogenic acid. Compound 3, mp 238-240°C (EtOH), PC R f 0.60 (system II), UV spectrum (EtOH, λ max , nm): 211, 274; gallic acid. We also investigated the accumulation dynamics of phenolic acids in leaves of C. hastata collected in 2000-2002 in Mukhorshibir Region (Buryatiya Republic) during various vegetative periods. The amounts of caffeic and chlorogenic [6, 7] and gallic [8] acids were determined during different development stages of the leaves (Table 1).We found that the total amounts of phenolic acids and chlorogenic acid reach a maximum during budding, 1.72 and 0.84%, respectively, and slightly decrease toward autumn. The accumulation dynamics of caffeic and gallic acids are different. Their content increases during plant development and reaches a maximum toward the end of vegetation. The amount of gallic acid remains almost constant during budding with a sharp increase in autumn. This is probably a result of the destruction of hydrolyzed tannins. The content of caffeic acid increases toward the end of vegetation. The correlation between the contents of caffeic and chlorogenic acids is explained by the fact that during autumn the esterase activity increases. This cleaves depside chlorogenic acid to quinic and caffeic acids. The amount of caffeic acid increases as a r...

Xanthones containing acetoxy, allyloxy, and aminohydroxyalkyloxy substituents at the C-1 position that are of interest as potential biologically active agents were prepared. The cholegogic action of 1-hydroxy-, 1-acetoxy-, and 1-allyloxy-substituted xanthones was investigated.Halenia corniculata (L.) Cornaz (Gentianaceae) is an annual plant that grows in wet and swampy habitats in Russia, Mongolia, and Manchuria [1, 2]. Significant populations of H. corniculata are concentrated east of Lake Baikal.The aerial part of this plant is used in Tibetan medicine as a replacement for "ser-tig" for treatment of "bile fever and infection" [3]. Decoction and tincture of H. corniculata in vodka are recommended in Siberian folk medicine as an appetite stimulant and digestion regulator and are indicated for gastritis, intestinal and stomach pain, liver diseases, colitis, and enterocolitis [4]. The herb is widely used in traditional medicine in East-Asian countries for liver diseases (hepatitis and cholecystitis) [5]. A polyphenol complex from H. corniculata possesses antioxidant and hepatoprotective action [6].Research on the chemical composition of plants of the Halenia genus showed that they are sources of xanthone aglycons and their glycosides [7-9].We previously described a rational method for isolating 1-hydroxy-2,3,5-trimethoxy-(1) and 1-hydroxy-2,3,4,5-tetramethoxyxanthones (2) from the aerial part of H. corniculata [10]. In the present article, we report the preparation of derivatives of these xanthones that contain various substituents at the C-1 position.Acetylation of 1 and 2 under standard conditions (pyridine-Ac 2 O) formed acetates 3 and 4 in yields of 88.6 and 90.4%, respectively.Alkylation of 1 and 2 by allylbromide in acetone in the presence of K 2 CO 3 [11] produced 1-allyloxy-2,3,5-trimethoxyxanthone (5, 95.5%) and 1-allyloxy-2,3,4,5-tetramethoxyxanthone (6, 92.8%).It was previously found that aromatic compounds in which the hydroxyl is esterified by 3-aminopropan-1,2-diol exhibit β-adrenoblocking properties with antihypotensive and antiarhythmic action. Aryl-and hetaryloxypropanolamines were prepared and studied [12]. We alkylated 1 and 2 with (chloromethyl)oxirane to synthesize analogs of this type of preparation, athenolol and anaprilin [13]. We found that 1 and 2 react with epichlorohydrin on brief heating in the presence of an interphase catalyst (0.1 eq) [14]. The reaction produces a mixture of diastereomeric epoxides (S)-7a,8a and (R)-7b,8b in overall yield 67-69% with predominance (2:1) of the (S)-diastereomers 7a,8a. Aminolysis of 7a,b with benzylamine by the literature method [15] gives pure 1-(3-benzylamino-2-hydroxy)-propoxy-2,3,5-trimethoxyxanthone (9).

581.192+582.936 L. M. Tankhaeva, and G. G. NikolaevaA method for quantitative determination of total γ-pyrone content in the aerial part of Halenia corniculata was developed. Their total content in various samples of the aerial part was investigated.We previously established that the principal active compounds from Halenia corniculata (L.) Cornaz (Gentianaceae) are xanthones and flavones [1].The development of objective methods for quantitative determination of the content of biologically active compounds in starting material and medicinal preparations is an important step in the development of medicinal preparations. Therefore, our task was to develop a method for quantitative determination of the total γ-pyrone content in the aerial part of Halenia corniculata.The present article also includes results from a study of the total γ-pyrone content in various samples of the aerial part of this plant.We used a chromato-spectrophotometric method for quantitative determination of the γ-pyrone content. The standard was 1-hydroxy-2,3,4,5-tetramethoxyxanthone (1), the dominant component of the total γ-pyrones. Its absorption maximum in the UV spectrum (260 ± 1) is close to those of the second dominant xanthone, 1-hydroxy-2,3,5-trimethoxyxanthone (257 ± 3), and luteolin (253 ± 1) and to that of the alcohol extract of the hydrolyzed raw material (254 ± 1) (Fig. 1). The analytical wavelength was 254 nm, which is situated between the peaks in the UV spectra of the xanthones, flavone, and the alcohol extract. It has been found that the optical density as a function of concentration for 1 is linear in the range 1.2·10 -6 -12.0·10 -6 g/mL.The optimal conditions for the extraction became clear during development of the quantitative determination method: extractant, 60% ethanol; extraction temperature, 90°C; particle size of raw material, 0.5-1 mm; raw-material/extractant ratio, 1/60; time and repetition of extraction: I, 60 min; II, 60 min; III, 45 min.The extract was purified of accompanying substances by chromatographic separation over a column of polyamide sorbent. Ballast substances (blue band in UV light) were eluted by water; γ-pyrones (absorbing band in UV light), by 95% ethanol. However, it was noted that preliminary elution with water gave effluents containing O-glycosides of γ-pyrones (TLC monitoring). In order to avoid these losses (up to 4%), the plant material was extracted with 60% ethanol containing HCl (5%). The glycoside bonds were completely destroyed in 1 h (TLC).A correction factor was introduced into the formula for quantitative determination of total γ-pyrones in the aerial part of Halenia corniculata. This took into account incomplete desorption from the column of the eluted substances. This coefficient (K elu ), equal to 1.093, was determined experimentally for 1 in a series of ten independent determinations. Table 1 gives the metrological parameters of the quantitative method for determining the total γ-pyrone content in the aerial part of Halenia corniculata (calculated for 1-hydroxy-2,3,4,5-tetramethoxy...