H. K. Wu

Kaempferol and quercetin flavonoids from Rosa rugosa

__________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 600–601, November–December, 2006.

APPLICATION OF PREPARATIVE HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY FOR SEPARATION OF ELATINE FROM DELPHINIUM SHAWURENSE

Abstract Preparative separation of elatine in Delphinium shawurense was achieved for the first time using high speed countercurrent chromatography (HSCCC). The separation was performed with a solvent system composed of ethyl acetate-chloroform-methanol-water (3:0.1:2:3, v/v) using the lower organic phase as a mobile phase under a revolution speed of 800 rpm. This yielded 72 mg of elatine at over 97% purity with an approximately 95% recovery. The chemical structure was identified by MS and NMR.

Preparative isolation of guaipyridine sesquiterpene alkaloid from Artemisia rupestris L. flowers using high‐speed counter‐current chromatography

Although the medicinal plant Artemisia rupestris L. has been widely researched for several decades, its alkaloids have never been isolated before. To our surprise, the alkaloids in the plant were not detected in the stems but detected in the flowers. Herein, a novel and strange guaipyridine sesquiterpene alkaloid with a carboxyl group named rupestine was purified successfully from the total alkaloids extracted from the flowers by high-speed counter-current chromatography (HSCCC). The two-phase solvent system used was composed of ethyl acetate-methanol-water (8:1:7, v/v/v). Fifty six milligrams of rupestine was obtained at over 97% purity and 95% recovery from 200 mg of the total alkaloids in one-step separation. Its structure was elucidated by spectroscopic methods including high resolution ESI-MS, (1)H NMR, (13)C NMR, Heteronuclear Multiple Bond Correlation (HMBC), Heteronuclear Single Quantum Coherence (HSQC), and Nuclear Overhauser Enhancement Spectroscopy (NOESY).

Isolation of esculetin from Cichorium glandulosum by high-speed countercurrent chromatography

Cichorium glandulosum Boiss et Hout (Compositae, Asteraceae) is widely used in Uigur folk medicine as a cholagogic and diuretic agent, to improve the appetite, to increase digestion, and to cure liver diseases etc. [1]. This plant is widely distributed in Xinjiang but its chemical composition has not been reported with the exception of the analysis of its essential oil [2]. Esculetin is the active principle of C. glandulosum. Biological studies have established its hepatoprotective activity [3]. Herein we report a method for isolating and purifying esculetin by preparative high-speed countercurrent chromatography (HSCCC). A crude sample of C. glandulosum was first analyzed by HPLC. The results showed that it contained esculetin and several unknown components. The sample was separated by HSCCC. Fractions containing esculetin were combined and dried. The yield of esculetin was 24 mg; the purity, 98%. Seeds (~1 kg) of C. glandulosum were extracted three times with ethanol (70%). The extracts were combined and evaporated to dryness under reduced pressure to afford a dry powder (150 g). The powder was dissolved in pure water (500 mL). The resulting solution was passed over a column of ion-exchange resin (1.1 kg, grade D 101) with elution by water (8 L) and ethanol (30%, 50, 70, and 95, 8 L each). The effluent from 50% ethanol was evaporated to dryness to afford a crude sample (223 mg). The whole procedure was carried out as follows. An upper phase consisting of CHCl 3:CH3OH:H2O (4:3:2) was pumped into the multiple carbon column of the chromatograph (HSCCC, model GS-10A2) at flow rate 9 mL/min using a model NS-1007 pump to create a constant current. After the column was filled with the upper phase through the sample-injection system, a solution of dry extract (223 mg) dissolved in the upper phase was introduced to the column. Then the lower organic phase was pumped into the column at flow rate 2 mL/min with the column rotating at 800 rpm. The column effluent was monitored by a UV detector at 254 nm. Peaks were collected manually according to the chromatogram. The collected fractions were analyzed by HPLC using CH3OH:CH3CO2H (0.3%) (31:69). The peak fraction obtained from the HSCCC chromatograph was identified using PMR and 13C NMR spectral data. PMR spectrum (400 MHz, DMSO-d 6, δ, ppm, J/Hz): 6.1 (1H, d, J = 9.6, H-3), 6.7 (1H, s, H-5), 6.9 (1H, s, H-8), 7.8 (1H, d, J = 9.6, H-4), 9.4 (1H, s, 6-OH), 10.2 (1H, s, 7-OH). 13C NMR spectrum (100 MHz, DMSO-d 6): 160.6 (C-2), 150.0 (C-6), 148.3 (C-7), 144.3 (C-4), 142.5 (C-9), 112.1 (C-5), 111.4 (C-3), 110.7 (C-10), 102.5 (C-8). These data agreed well with those published [4] and identified the isolated compound as esculetin.

Composition of essential oil from seeds of Metasequoia glyptostroboides growing in China

Chongqing, China; 2) Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China, e-mail: wuhankui@mails.gucas.ac.cn; 3) S. Yu. Yunusov Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (99871) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, p. 278, May-June, 2007. Original article submitted February 8, 2007.

2-ISOPROPYL-6-METHYLPYRIMIDIN-4(3H)-ONE AND TARAXASTEROL FROM THE STEMS OF Cichorium glandulosum

0009-3130/11/4704-0664 2011 Springer Science+Business Media, Inc. 1) Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi, 830011, P. R. China, e-mail:haji@xjb.ac.cn; 2) College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan, 455002, P. R. China, e-mail:hkwu@aynu.edu.cn. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 581–582, July–August, 2011. Original article submitted January 20, 2010. Chemistry of Natural Compounds, Vol. 47, No. 4, September, 2011 [Russian original No. 4, July–August, 2011]