Guan Ye

Identification of major alkaloids and steroidal saponins in rat serum by HPLC-diode array detection-MS/MS following oral administration of Huangbai-Zhimu herb-pair Extract

Huangbai-Zhimu herb-pair (HBZMHP) is a widely used Chinese traditional medicine formula in treating various diseases; however, its active components have remained unknown. In this paper, serum chemistry and combined high-performance liquid chromatography (HPLC), diode-array detection and mass-spectrometry (MS) techniques were used to study the constituents of HBZMHP extract absorbed into rat serum after oral administration. A total of nine characteristic HPLC peaks in the TIC chromatograms were identified as magnoflorine (1), menisperine (2), palmatine (3), berberine (4), timosaponin N or timosaponin E1 (5), timosaponin D (6), timosaponin BIII, anemarsaponin C or xilingsaponin B (7) timosaponin BII (8) and timosaponin AIII (9). All of the identified peaks were constituents of HBZMHP extract. The results narrow the range of active compounds to be found in HBZMHP extract, and pave the way for the follow-up action mechanism research.

Ellagic acid derivatives from the stem bark of Dipentodon sinicus

Ellagic acid derivatives were isolated from Dipentodon sinicus and their structures were identified as 3,3′,4′-tri-O-methylellagic acid (1), 3,3′-di-O-methylellagic acid (2), 4,4′-di-O-methylellagic acid (3), 3,3′-di-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (4), 3,3′,4′-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (5), 3,3′-di-O-methylellagic acid-4′-O-β-D-glucopyranoside (6), and ellagic acid (7). All the compounds were isolated for the first time from the title plant.

Complete NMR spectral assignments of two new iridoid diastereoisomers from the flowers of Plumeria rubra L. cv. acutifolia

Two new iridoid diastereoisomers (1, 2), together with five known compounds, were isolated from the flowers of Plumerian rubra L. cv. acutifolia. Their structures were elucidated by the means of in‐depth spectroscopic and mass‐spectrometric analyses, particularly 1D and 2D NMR spectroscopy. Copyright

Characterization of anti-Coxsackie virus B3 constituents of Radix Astragali by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

To profile the anti-Coxsackie virus B3 constituents of Radix Astragali, an HPLC-DAD-MS(n) analytical method, combined with an in vivo test, has been developed to identify the constituents of the active part, which has been demonstrated to have potency to inhibit the proliferation of virus in cardiac muscle, alleviate infraction in heart and elevate the survival rate of the animal. By comparing their retention time and MS data with those obtained from the authentic compounds and the published data, a total of 19 compounds, including 11 isoflavonoids and eight saponins, were identified, among which one pterocarpane glucoside was reported for the first time. The present study provides an approach to rapidly screening bioactive constituents in traditional Chinese medicines.

Components of Sophora alopecuroides seeds

The seed of Sophora alopecuroides (Fabaceae) is a traditional Chinese medicine called locally “kudouzi”, which is used as an antibacterial and antiinflammatory agent and is widely distributed in northwest China. Previous phytochemical studies of S. alopecuroides led to the isolation alkaloids, flavonoids, steroids, and organic acids [1]. Herein we describe the isolation and structure determination of the isolated compounds. Dried seeds of S. alopecuroides (5 kg) were powdered and refluxed with petroleum ether to degrease them (1h × 3). The undissolved powder was extracted with boiling 95% aqueous EtOH (1h × 3). The extract was evaporated under vacuum to give a residue (135 g). The extract was subjected to silica gel eluted with gradient MeOH:CHCl3 (20:1–3:1) to afford fractions A–D. Fraction A (17.0 g) was further subjected to silica gel chromatography eluted with MeOH–CHCl3 gradient (30:1–15:1) and Sephadex LH-20 eluted with MeOH, successively, to give ferulic acid (1) (80 mg) [2], butein (2) (100 mg) [3], sulfuretin (3) (18 mg) [3], 7-hydroxy-3′,4′-methylenedioxyisoflavone (4) (6 mg) [4], and sophocarpine (5) (24 mg) [5]. Fraction B (21.3 g) was purified by silica gel eluted with MeOH–CHCl3 (20:1–8:1) and Sephadex LH-20 eluted with MeOH, successively, to give 7,3′,4′-trihydroxyflavone (6) (26 mg) [6], dihydrophaseic acid (7) (75 mg) [7], matrine (8) (17 mg) [5], and sophoridine (9) (21 mg) [5]. Fraction C (18.1 g) was subjected to silica gel eluted with MeOH–CHCl3 (5:1) to afford piscidic acid (10) (491 mg) [8], sophoramine (11) (21 mg) [9], and cytisine (12) (36 mg) [10]. Fraction D (12.3 g) was subjected to Sephadex LH-20 eluted with MeOH to give butein-4-O-β-D-glucopyranoside (13) (195 mg) [3] and 7,3′,4′-trihydroxyflavanone-7-O-β-D-glucopyranoside (14) (16 mg) [11]. The structure of the compounds was deduced from spectroscopic experiments, and all the data were in good agreement with literature. Sulfuretin (3), orange powder, ESI-MS (negative) m/z: 269 [M–H]–. PMR spectrum (400 MHz, DMSO-d6, δ, ppm, J/Hz): 6.62 (1H, s, H-10), 6.69 (1H, d, J = 8.4, H-6′), 6.83 (1H, d, J = 8.1, H-4), 6.74 (1H, br.s, H-7), 7.23 (1H, d, J = 8.1, H-5), 7.44 (1H, br. s, H-2′), 7.59 (1H, d, J = 8.4, H-5′); 13C NMR spectrum (100 MHz, DMSO-d6, δ, ppm): 145.7 (C-2), 181.3 (C-3), 125.8 (C-4), 116.0 (C-5), 167.5 (C-6), 98.4 (C-7), 166.1 (C-8), 113.3 (C-9), 112.9 (C-10), 123.5 (C-1′), 112.0 (C-2′), 145.4 (C-3′), 148.0 (C-4′), 117.9 (C-5′), 124.6 (C-6′). These data agreed with those published [3]. Dihydrophaseic acid (7), white powder, ESI-MS (negative) m/z: 281 [M–H]–. PMR spectrum (400 MHz, DMSO-d6, δ, ppm, J/Hz): 0.77 (3H, s, H-14), 0.97 (3H, s, H-15), 1.53 (1H, m, H-8α), 1.58 (1H, m, H-10α), 1.69 (1H, m, H-8β), 1.85 (1H, m, H-10β), 1.96 (3H, s, H-12), 3.53 (1H, d, J = 7.2, H-13α), 3.60 (1H, d, J = 7.2, H-13β), 3.87 (1H, m, H-9), 5.66 (1H, s, H-2), 6.42 (1H, d, J = 15.6, H-4), 7.84 (1H, d, J = 15.6, H-5); 13C NMR spectrum (100 MHz, DMSO-d6, δ, ppm): 166.9 (C-1), 118.0 (C-2), 149.5 (C-3), 129.5 (C-4), 135.1 (C-5), 81.5 (C-6), 48.1 (C-7), 43.8 (C-8), 63.8 (C-9), 45.4 (C-10), 85.8 (C-11), 20.9 (C-12), 75.4 (C-13), 16.2 (C-14) 19.6 (C-15). These data corresponded with those in the literature [7]. Thus, our systematic phytochemical study on S. alopecuroides led to the isolation of 14 compounds, in which 9 compounds (1–4, 6, 7, 10, 13, 14) were isolated from the species for the first time. Among them, compounds sulfuretin (3) and dihydrophaseic acid (7) were the first to be isolated from the the genus Sophora. On the other hand, to the best of our knowledge, compounds 3 and 7 were also the first reports on the occurrence of the aurone and sesquiterpene from this genus, respectively. These compounds add to the types of secondary metabolites of the genus Sophora and may contribute to the chemotaxonomic characteristics of this species.

A new C-glucoside from Commelina communis

A new C-glucoside, 3,4-epoxy-5-hydroxymethyl benzoate 2-C-β-glucoside (1), together with a known alkaloid, 1H-indole-3-carbaldehyde (2), were isolated from the whole plant of Commelina communis L. The structures of these compounds were determined by 1D, 2D NMR and MS techniques.

Characterization of the Multiple Absorbed Constituents in Rats after Oral Administration of Chai-Huang Decoction by Liquid Chromatography Coupled with Electrospray-Ionization Mass Spectrometry

A rapid, sensitive, and specific method by high‐performance liquid chromatography (HPLC) coupled to diode‐array detection (DAD) and tandem mass spectrometry (MS) techniques was developed for the identification of absorbed constituents and their metabolites in rats after the oral administration of a Chai‐Huang decoction (CHD), which consists of Bupleurum chinense and Scutellaria baicalensis in the proportion 1 : 1 (w/w). By comparing their retention times and MS data with those of authentic compounds and published data, a total of 14 compounds were identified in the CHD samples. In addition, eleven and seven compounds were characterized in the urine and serum samples of the rats, respectively. The results indicated that the main absorbed constituents were chrysin‐6‐C‐arabinosyl‐8‐C‐glucoside, chrysin‐6‐C‐glucosyl‐8‐C‐arabinoside, baicalin, wogonin‐5‐O‐glucoside, oroxylin A‐7‐O‐glucuronide, wogonoside, saikosaponin A, saikosaponin C, saikosaponin D, baicalein, and wogonin. These compounds might be responsible for the curative effects of the CHD. The findings demonstrated that the proposed method could be used to rapidly and simultaneously analyze and screen the multiple absorbed bioactive constituents in a formula of traditional Chinese medicines (TCM). This is very important not only for the pharmaceutical discovery process and the quality control of crude drugs but also to explain the mechanisms of action of TCM.

Ellagic acid glycosides from the stem bark of Aphananthe aspera

Five ellagic acid glycosides were isolated from Aphananthe aspera and their structures were identified as 3-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (1), 3-O-methylellagic acid-4′-O-β-D-xylopyranoside (2), 3,3′-di-O-methylellagic acid-4′-O-β-D-xylopyranoside (3), 3,3′, 4-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (4), and 3,3′-di-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (5) on the basis of spectroscopic analysis. Compound 1 is new, and all the compounds were isolated for the first time from the title plant.

Calycosin 7-O-β-D-glucopyranoside, an anti-HIV agent from the roots of Astragalus membranaceus var. mongholicus

The roots of Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao (Leguminosae) have long been used as traditional Chinese medicine to cure chronic diarrhea, prolapse of the rectum, hematochezia and abnormal uterine bleeding, edema, anemia, albuminuria in chronic nephritis, and diabetes in China [1]. Calycosin 7-O-β-D-glucopyranoside (1) isolated from this medicine possesses multiple biological and pharmacological activities such as an alleviating effect on osteoarthritis [2], a protective effect on rat hepatocytes [3], an inhibitory effect on COX-2 activity [4], and antimicrobial and superoxide anion scavenging activities [5]. Additionally, this compound can also efficaciously increase the fluidity of brain cell membrane in ischemia-reperfusion rats [6, 7]. Natural products provide a large reservoir for screening of anti-HIV-1 agents because of their novel structure, anti-viral properties and structural diversity, such as β-galactose-specific lectin [8], propolis [9], betulinic acid [10], a series of 4-phenylcoumarins [11], xanthohumol [12], etc. Unfortunately, the anti-HIV-1 activities of 1 have not been reported. In the present research, cytotoxicity assay, syncytium reduction assay on C8166 cells, and the inhibition assay of HIV-1 induced cytopathogenicity on MT-4 cells for calycosin 7-O-β-D-glucopyranoside were carried out for the first time. The phytochemical investigation on A. membranaceus led to the isolation and characterization of calycosin 7-O-β-Dglucopyranoside. Colorless needles (methanol); mp 221~222° C; ESIMS (positive mode) m/z: 447 [M + H]+. Chemistry of Natural Compounds, Vol. 45, No. 2, 2009

Determination of two metabolites of calycosin-7-O-β-d-glucopyranoside in rat urine by HPLC.

A simple and specific analytical method for the simultaneous determination of the two metabolites of calycosin-7-O-beta-D-glucopyranoside, calycosin-7-O-beta-D-glucuronic acid methyl ester (M-1) and calycosin (M-2), in rat urine was developed using high-performance liquid chromatography. Quercetin was employed as an internal standard. The correlation coefficients of the calibration curves were higher than 0.999; both intra- and inter-day precisions of two metabolites were determined and their RSD did not exceed 10%. The accuracy and linear range were investigated in detail. The cumulative urinary excretions of two metabolites were measured.