Yun-Bao Ma

Kunming University of Science and Technology, Yün-nan, Yunnan, China

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Publications (64)125.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hepatitis B induced by HBV is a serious health problem. Artemisia capillaris (Yin-Chen) has long been used to treat hepatitis in traditional Chinese medicine. Coumarins, flavonoids and organic acids were revealed as its hepatoprotective and choleretic components, but its anti-HBV active components remain unknown. This current study focused on its anti-HBV active constituents by various chromatographic methods.
    Journal of ethnopharmacology. 09/2014;
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    ABSTRACT: Thirty-nine caudatin analogs were designed and synthesized. Their anti-hepatitis B virus (HBV) activities were evaluated in vitro. Among them, twenty-three compounds showed much better anti-HBV activity than caudatin, and eleven compounds significantly inhibited the HBV DNA replication with IC50 values < 10 μΜ. Interestingly, three compounds (22, 28, 29) exhibited excellent activity against the secretion of HBsAg (IC50 = 63.02 μΜ, 52.81 μΜ, 56.08 μΜ), HBeAg (IC50 = 204.80 μΜ, 173.51 μΜ, 70.39 μΜ), along with HBV DNA replication (IC50 = 24.55 μΜ, 5.69 μΜ, 8.23 μΜ) with lower cytotoxicity. The structure-activity relationships (SARs) of these caudatin analogs were also discussed.
    Medicinal chemistry (Shariqah (United Arab Emirates)). 09/2014;
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    ABSTRACT: Two new sesquiterpenoid glycosides, nicotabalactonecoside (1) and nicotabadiolcoside (2), along with four known terpenoids (3-6) were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1 and 2 were determined as dihydrodeacetylphytuberin-2-one 11-O-β-d-glucopyranoside and 1,2-dehydro-4-epieremophil-9-ene-11,12-diol 12-O-β-d-glucopyranoside by extensive spectroscopic analyses (HR-ESI-MS, UV, IR, 1D, and 2D NMR) and chemical method. Compound 1 is an unusual phytuberin-type sesquiterpenoid with a 6/5/5 tricyclic system.
    Journal of Asian natural products research. 06/2014;
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    ABSTRACT: Dehydroandrographolide and andrographolide, two natural diterpenoids isolated from Andrographis paniculata possessed activity against HBV DNA replication with IC50 values of 22.58 and 54.07 μM and low SI values of 8.7 and 3.7 in our random assay. Consequently, 48 derivatives of dehydroandrographolide and andrographolide were synthesized and evaluated for their anti-HBV properties to yield a series of active derivatives with lower cytotoxicity, including 14 derivatives against HBsAg secretion, 19 derivatives against HBeAg secretion and 38 derivatives against HBV DNA replication. Interestingly, compound 4e could inhibit not only HBsAg and HBeAg secretions but also HBV DNA replication with SI values of 20.3, 125.0 and 104.9. Furthermore, the most active compound 2c with SI value higher than 165.1 inhibiting HBV DNA replication was revealed with the optimal log P value of 1.78 and log D values. Structure–activity relationships (SARs) of the derivatives were disclosed for guiding the future research toward the discovery of new anti-HBV drugs.
    Bioorganic & Medicinal Chemistry Letters. 05/2014; 24(10):2353–2359.
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    ABSTRACT: The ethyl acetate extract of the flower of Albizia julibrissin was isolated and purified by silica gel, Sephadex LH-20 and MCI GEL CHP-20P column chromatography to yield 29 compounds. Their structures were elucidated as 8-hydroxy-2, 6-dimethyl-2E, 6Z-octadienoic acid (1), 8-O-formyl-2, 6-dimethyl-2E, 6Z-octadienoic acid (la), 8-hydroxy-2, 6-dimethyl-2E, 6E-octadienoic acid (2), 8-O-formyl-2, 6-dimethyl-2E, 6E-octadienoic acid (2a), (2E, 6S)-2, 6-dimethyl-6-O-beta-D-xylpyranosyloxy-2, 7-menthia-folic acid (3), clovan-2beta, 9alpha-diol (4), 2beta-O-formyl-clovan-9alpha-ol (4a), 2beta, 9alpha-O-diformyl-clovan (4b), vomifoliol (5), (6S, 9R)-roseoside (6), vanillin (7), 4-O-ethylgallic acid (8), 3-ethoxy4-hydroxy-benzoic acid (9), p-hydroxybenzaldehyde (10), gallic acid (11), protocatechoic acid (12), stearic acid (13), palmitic acid (14), 2, 3-dihydroxypropyl hexadecanoate (15), linoleic acid (16), scopoletin (17), indole-3-carboxaldehyde (18), 2-furoic acid (19), 5-(hydroxymethyl)-2-furaldehyde (20), (22E, 24R)-5alpha, 8alpha-epidioxy-ergosta-6, 22-dien-3beta-ol (21), (22E, 24R)-5alpha, 8alpha-epidioxy-ergosta-6, 9, 22-trien-3beta-ol (22), (+)-lariciresinol 9'-stearate (23), formononetin (24) and uridine (25). Compounds 1a, 2a, 4a and 4b were new artifacts from the separation process, and others were obtained from A. julibrissin for the first time.
    05/2014; 39(10):1845-51.
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    ABSTRACT: Six new 14 - noreudesmane sesquiterpenoids, nicotabacosides A-F (1-6), along with five known sesquiterpenoids (7-11), were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1-6 were elucidated as isorishitin 3 - O - β - D - glucopyranoside (1), rishitin 3 - O - β - D - glucopyranoside (2), rishitin 2 - O - β - D - glucopyranosde (3), 1, 6 - dehydro - rishitin 3 - O - β - D - glucopyranoside (4), 2 - hydroxyl - ligudentatol 3 - O - β - D - glucopyranoside (5) and oxyglutinsone 3 - O - β - D - glucopyranoside (6) based on extensive spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR). Their absolute configurations were determined by the X-ray single-crystal diffraction and comparison of their electronic circular dichroism (ECD) spectra.
    Fitoterapia 04/2014; · 2.23 Impact Factor
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    ABSTRACT: Dehydroandrographolide and andrographolide, two natural diterpenoids isolated from Andrographis paniculata possessed activity against HBV DNA replication with IC50 values of 22.58 and 54.07μM and low SI values of 8.7 and 3.7 in our random assay. Consequently, 48 derivatives of dehydroandrographolide and andrographolide were synthesized and evaluated for their anti-HBV properties to yield a series of active derivatives with lower cytotoxicity, including 14 derivatives against HBsAg secretion, 19 derivatives against HBeAg secretion and 38 derivatives against HBV DNA replication. Interestingly, compound 4e could inhibit not only HBsAg and HBeAg secretions but also HBV DNA replication with SI values of 20.3, 125.0 and 104.9. Furthermore, the most active compound 2c with SI value higher than 165.1 inhibiting HBV DNA replication was revealed with the optimal logP value of 1.78 and logD values. Structure-activity relationships (SARs) of the derivatives were disclosed for guiding the future research toward the discovery of new anti-HBV drugs.
    Bioorganic & medicinal chemistry letters 03/2014; · 2.65 Impact Factor
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    ABSTRACT: 28 Derivatives of panaxadiol (PD) and panaxatriol were synthesized and evaluated for their anti-HBV activity on HepG 2.2.15 cells, of which 17 derivatives inhibited HBV DNA replication. Compounds 4, 9, 10, 14, and 15 showed moderate activity against HBV DNA replication with IC50 values ranged from 7.27 to 28.21 μM compared with PD. In particular, 3-O-2'-thenoyl panaxadiol (4) inhibited not only HBV DNA replication (IC50 = 16.5 μM, SI > 115.7) but also HBsAg (IC50 = 30.8 μM, SI > 62.0) and HBeAg (IC50 = 18.2 μM, SI > 105.14) secretions. Their structure-activity relationships were discussed for guiding future research toward the discovery of new anti-HBV agents.
    Natural products and bioprospecting. 01/2014; 4:163-174.
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    ABSTRACT: Three new polyacetylenes, 8 - (Z) - decene - 4, 6-diyne - 1, 3, 10-triol (1), 1, 3S, 8S - trihydroxydec - 9 - en - 4, 6 - yne (2), 3S, 8S - dihydroxydec - 9 - en - 4, 6 - yne 1 - O - β - D - glucopyranoside (3), and one new glucosyl caffeoate, 1 - O - ethyl - 6 - O - caffeoyl - β - D - glucopyranose (4), together with 34 known compounds were isolated from Artemisia capillaris. The structures of the new compounds were determined by extensive spectroscopic analyses including 1D and 2D NMR, HRESIMS, [α]D and CD experiments. Among them, 19 compounds showed activity inhibiting HBsAg secretion; 20 compounds showed activity inhibiting HBeAg secretion; and 25 compounds possessed inhibitory activity against HBV DNA replication according to our anti-HBV assay on HepG 2.2.15 cell line in vitro. The most active compound 12 could inhibit not only the secretions of HBsAg and HBeAg, but also HBV DNA replication with IC50 values of 15.02μM (SI=111.3), 9.00μM (SI=185.9) and 12.01μM (SI=139.2).
    Fitoterapia 01/2014; · 2.23 Impact Factor
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    ABSTRACT: (+)-Paeoveitol and (-)-paeoveitol, a pair of new norditerpene enantiomers, were isolated from the root of Paeonia veitchii. Their structures and absolute configurations were determined on the basis of extensive analysis of 1D and 2D NMR spectra, crystal X-ray diffraction, and electronic circular dichroism (ECD). A possible biogenesis involving two molecules of paeoniflorin was postulated.
    Organic Letters 12/2013; · 6.14 Impact Factor
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    ABSTRACT: (±)-Sweriledugenin A, a pair of novel enantiomeric lactones, were isolated from Swertia leducii under the guidance of LC-MS investigation. The enantiomeric separation was achieved by HPLC on a chiral column. Their structures were determined by extensive NMR spectra, X-ray, and quantum calculations. (+)-Sweriledugenin A and (-)-sweriledugenin A showed activities inhibiting HBV DNA replication with the IC50 values of 36.86 and 26.55 μM on the HepG 2.2.15 cell line in vitro.
    Organic Letters 12/2013; · 6.14 Impact Factor
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    ABSTRACT: Three new secoiridoids, swermacrolactones A-C (1-3), together with fourteen known compounds were isolated from Swertia macrosperma. Their structures were elucidated based on extensive spectroscopic analyses (IR, UV, MS, 1D and 2D NMR). By anti-HBV assay on the Hep G 2.2.15 cell line in vitro, the most active compound, luteolin (9), inhibited the secretion of hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) with IC50 values of 0.02 and 0.02mM, respectively.
    Fitoterapia 06/2013; · 2.23 Impact Factor
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    ABSTRACT: Four new triterpenoids, sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4), along with nineteen known compounds (5-23) were isolated from Swertia yunnanensis. Based on extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D), the structures of sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4) were elucidated as taraxer-14-ene- 3α,6β-diol, oleanolic acid 28-O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranoside, 2α,3β-di-hydroxyolean-12-en-28-oic acid 28-O-β-D-glucopyranosyl (1→6)-β-D- glucopyranosyl (1→6)-β-D-glucopyranosyl (1→2)-β-D-glucopyranoside and hederagenin 28-O-β-D-glucopyranosyl (1→6)-β-D-glucopyranosyl (1→6)-β-D- glucopyranosyl (1→2)-β-D-glucopyranoside, respectively. Twenty-two compounds were evaluated for their anti-HBV activities on the HepG 2.2.15 cell line in vitro, of which nine compounds showed potent anti-HBV activities. Compounds 1, 5-6, 14-16 and 19 showed activities against the secretion of HBsAg (IC50 values from 0.10 to 1.76 mM) and HBeAg (IC50 values from 0.04 to 1.41 mM), and ccompounds 11 and 13-16 exhibited significant inhibition on HBV DNA replication (IC50 values from 0.01 to 0.09 mM).
    Fitoterapia 06/2013; · 2.23 Impact Factor
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    ABSTRACT: Five compounds were isolated from Capsicum annuum by means of various chromatographic techniques (silica gel, Sephadex LH-20, MCI GEL CHP-20P and HPLC), and their structures were determined as luteolin-7-O-[2"-O-(5"-O-sinapoyl)-beta-D-apiofuranosyl]-beta-D-glucopyranoside (1), uridine (2), adenosine (3), 7-hydroxy-6-methoxy cinnamic acid ethyl ester (4) and 7-hydroxy cinnamic acid ethyl ester (5) by extensive spectroscopic analyses (UV, IR, MS, 1D- and 2D-NMR). Among them, compound 1 is a new flavone glycoside named as capsicuoside A, and cmpounds 2-5 are isolated for the first time from the fruits of C. annuum.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 06/2013; 38(12):1934-7.
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    ABSTRACT: Two new xanthones, 8-O-β-D-glucopyranosyl-1-hydroxy-2,3,5-trimethoxyxanthone (1) and 8-O-[β-D-xylopyranosyl-(1 → 6)-β-D-glucopyranosyl]-1-hydroxy-2,3,5-trimethoxyxanthone (2), along with eighteen known xanthones (3-20) were isolated from Swertia mussotii. Their structures were elucidated on the basis of extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D). All compounds were evaluated for their anti-hepatitis B virus activities on HepG 2.2.15 cells line in vitro, and compounds 3-10 exhibited significant activity inhibiting hepatitis B virus DNA replication with IC50 values from 0.01 mM to 0.13 mM. Compounds 3-5 showed remarkable activity with IC50 values of 0.77, > 0.98, and 0.21 mM for HBsAg, and < 0.62, 0.35, and 0.04 mM for HBeAg, respectively. Meanwhile, the effects of different substitutions on the anti-hepatitis B virus activity of xanthones from S. mussotii were discussed.
    Planta Medica 04/2013; · 2.35 Impact Factor
  • Chang-An Geng, Yun-Bao Ma, Ji-Jun Chen
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    ABSTRACT: One unusual dimeric tropane alkaloid, bishyoscyamine, was isolated from the roots of Anisodus acutangulus, whose structure including the absolute stereochemistry was unambiguously determined based on extensive 1D NMR and 2D NMR, HR-ESI-MS [α]D and CD spectroscopic analyses. To our knowledge, bishyoscyamine is the first example of tropane alkaloid dimer condensed by a CN bond.
    Chinese Chemical Letters 03/2013; 24(3):236–238. · 1.18 Impact Factor
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    ABSTRACT: In the screening search for Hepatitis B virus inhibitory agents from medicinal plants, the ethanol extract of Piper longum Linn. was found to possess superior anti-HBV activity in vitro. Bioassay-guided fractionation coupled with repeated purification resulted in the isolation of four new compounds, involving two new glycosides longumosides A (1) and B (2) and two new amide alkaloids erythro-1-[1-oxo-9(3,4-methylenedioxyphenyl)-8,9-dihydroxy-2E-nonenyl]-piperidine (3), threo-1-[1-oxo-9(3,4-methylenedioxyphenyl)-8,9-dihydroxy-2E-nonenyl]-piperidine (4), as well as two compounds 3β,4α-dihydroxy-2-piperidinone (5), 5,6-dihydro-2(1H)-pyridinone (6) from natural source for the first time. The structures of the four new compounds were determined by extensive analyses of the MS, IR, 1D and 2D NMR data. Besides, the compounds 2-6, together with the known compounds 7-11 obtained previously, were assayed for their anti-HBV activity by using Hep G 2.2.15 cell line in vitro. Results suggested the compound piperine (7) possessed remarkable inhibitory HBV activity, against the secretion of hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) with the Selectivity Index (SI) values of 15.7 and 16.8, respectively.
    Bioorganic & medicinal chemistry letters 02/2013; · 2.65 Impact Factor
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    ABSTRACT: A series of hemslecin A derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activities, namely, inhibiting the secretion of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and HBV DNA replication on HepG 2.2.15 cells. Most of the derivatives showed enhanced anti-HBV activities, of which compounds A1-A7, B5, C and E exhibited significant activities inhibiting HBV DNA replication with IC(50) values of 2.8-11.6μM, comparable to that of the positive control, tenofovir. Compounds A1-A3, A5, B5, and C displayed low cytotoxicities, which resulted in high SI values of 89.7, 55.6, 77.8, >83.4, >55.8, and >150.5, respectively.
    Bioorganic & medicinal chemistry letters 01/2013; · 2.65 Impact Factor
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    ABSTRACT: Five unusual lactonic enamino ketones, gentiocrucines A-E (1-5), were isolated from Swertia macrosperma and S. angustifolia. Their structures were determined based on extensive spectroscopic analyses (IR, UV, MS, 1D- and 2D-NMR). By anti-HBV assay on the HepG 2.2.15 cell line in vitro, compound 1 inhibited both the secretion of hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) with IC50 values of 3.14 and 3.35 mM, and compound 5 only inhibited the secretion of HBsAg with an IC50 value of 2.07 mM.
    Planta Medica 10/2012; · 2.35 Impact Factor
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    ABSTRACT: Mulberrofuran G (1) and isomulberrofuran G (2), a pair of isomeric Diels-Alder-type adducts, were isolated from the root bark of Morus alba L. Isomulberrofuran G (2) as a new IIB-type Diels-Alder-type adduct, was elucidated by extensive (1)H, (13)C, and two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectroscopic analyses. A fragmentation study on compounds 1 and 2 was performed by high-resolution electrospray ionization (ESI) multistage tandem mass spectrometry linked with ion-trap (IT) and time-of-flight (TOF) mass analyzers (ESI-MS(n)/IT-TOF) in negative mode, which resulted in obviously different fragmentations. In the MS(2) experiments, the characteristic ions at m/z 451 and 439 could be revealed as their respective diagnostic ions. Mulberrofuran G (1) showed moderate activity, inhibiting hepatitis B virus (HBV) DNA replication with the IC(50) value of 3.99 μM, according to the anti-HBV assay on the HepG 2.2.15 cell line in vitro.
    Journal of Agricultural and Food Chemistry 07/2012; 60(33):8197-202. · 3.11 Impact Factor