Shuang-Cheng Ma

Antiviral Chinese medicinal herbs against respiratory syncytial virus.

Forty-four medicinal herbs were tested for antiviral activities against respiratory syncytial virus (RSV) by means of the cytopathologic effect (CPE) assay. Twenty-seven of the 44 medicinal herbs showed potent or moderate antiviral activities against RSV with 50% inhibition concentration (IC(50)) ranging from 6.3 to 52.1 microg/ml, and with selectivity index (SI) ranging from 2.0 to 32.1. Further purification of the active extracts from Sophora flavescens Ait. and Scutellaria baicalensis Georgi led to the identification of anagyrine (2), oxymatrine (7), sophoranol (10), wogonin (12), and oroxylin A (13) as the potent anti-RSV components.

Antiviral activities of flavonoids and organic acid from Trollius chinensis Bunge.

The flower of Trollius chinensis Bunge is used for treating upper respiratory infections, pharyngitis, tonsillitis, and bronchitis in Chinese folk medicine. The antiviral activities of the crude extract, total flavonoids, orientin, vitexin and proglobeflowery acid isolated from the flowers of T. chinensis against parainfluenza type 3 (Para 3) virus were investigated. The results showed that the crude extract and total flavonoids exhibited a weak antiviral activity against Para 3. Orientin and vitexin demonstrated potent or moderate antiviral activity against Para 3. Proglobeflowery acid showed weak antiviral activity against Para 3.

New Antiviral Cassane Furanoditerpenes from Caesalpinia minax

A bioassay-guided study led to the isolation of five new cassane furanoditerpenes, designated as caesalmin C (1), D (2), E (3), F (4), and G (5), along with stigmasterol (6) from the seeds of Caesalpinia minax. The (1)H and (13)C NMR spectra were completely assigned by using a combination of 2D NMR analyses. The structures of all five furanoditerpenes were confirmed by X-ray analyses. The structure of 6 was verified by X-ray analysis for the first time. The bioassay results showed that the anti-Para3 virus activity of tetracyclic furanoditerpenoids 1-4 is more potent than that of the furanoditerpenoid lactone 5, which is in turn better than 6. As the major components of the plant possess significant potent activity, it may be feasible to develop new antiviral agents from this source.

Molecular Structures and Antiviral Activities of Naturally Occurring and Modified Cassane Furanoditerpenoids and Friedelane Triterpenoids from Caesalpinia minax

Further investigation of the active components of the chloroform fraction of the seeds of Caesalpinia minax led to the isolation of a new cassane furanoditerpenoid, caesalmin H (1), together with two known furanoditerpenoid lactones, caesalmin B (2) and bonducellpin D (3). Reduction of the naturally abundant caesalmin D (9), E (10) and F (11) resulted in three new furanoditerpenoid derivatives 4-6. Phytochemical study of the stem of the same plant and subsequent reduction afforded two friedelane triterpenoids (7-8), which were identified by spectroscopic methods. Compounds 1-2 and 4-8 were corroborated by single crystal X-ray analysis. The factors governing the reduction of cassane furanoditerpenoids and friedelane triterpenoids were investigated by correlating the crystallographic results with density functional theory. The inhibitory activities of 2-8 on the Para3 virus were evaluated by cytopathogenic effects (CPE) reduction assay.

Structure and antiviral properties of macrocaesalmin, a novel cassane furanoditerpenoid lactone from the seeds of Caesalpinia minax Hance ☆

Abstract A novel cassane-type furanoditerpenoid lactone, named macrocaesalmin, possessing a ten-membered macrocyclic 1,5-diketone ring and an unprecedented cis B/D ring fusion mode, has been isolated from the seeds of Caesalpinia minax Hance. Its structure was elucidated from detailed 1D and 2D NMR spectral analyses and X-ray crystallography, and density-functional optimization showed that cis fusion of the B/D ring is more stable than the trans mode. Macrocaesalmin was found to exhibit inhibitory activity against RSV, but not for Flu-A and Para-3 viruses.

Furanoditerpenoid lactones from the seeds of Caesalpinia minax Hance

Two furanoditerpenoid lactones, were isolated from the seeds of Caesalpinia minax Hance. Their structures and stereochemistry have been established by spectral data and single crystal X-ray analysis.

Antiviral constituents against respiratory viruses from Mikania micrantha.

Phytochemical investigation of the dried aerial parts of Mikania micrantha led to the isolation of a new sesquiterpene, 3beta-acetoxy-1,10-epoxy-4-germacrene-12,8;15,6-diolide (1), along with six known constituents: 1,10-epoxy-4-germacrene-12,8;15,6-diolide (2), dihydromikanolide (3), potassium mikanin 3-sulfate (4), mikanin (5), alpinetin (6), and ergosta-7,22-dien-3beta-ol (7). Their structures were elucidated by spectroscopic methods, and the molecular structures and stereochemistry of sesquiterpene lactones 1-3 were revealed by single-crystal X-ray analysis. Compound 2 showed moderate activity against respiratory syncytial virus (IC(50) = 37.4 uM) and parainfluenza type 3 virus (IC(50) = 37.4 uM) with a therapeutic index (TI) of 16.0 for both compounds. Compound 4, the main component of M. micrantha, exhibited inhibitory activity against parainfluenza type 3 virus with IC(50) (19.7 uM) and TI (24.0) values comparable to those of ribavirin, serving as a positive control.

Isolation and characterization of spirocaesalmin, a novel rearranged vouacapane diterpenoid from Caesalpinia minax Hance

Spirocaesalmin, a novel rearranged vouacapane diterpenoid that exhibits significant activity against respiratory syncytial virus, possesses a new carbon skeleton with a spiro-CD ring system.

Tandem Mass Spectrometry for Structural Identification of Sesquiterpene Alkaloids from the Stems of Dendrobium nobile Using LC-QToF*

Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation provides a tool for the identification and characterization of the alkaloids from D. nobile. A total of nine sesquiterpene alkaloids were characterized by ultrahigh-performance liquid chromatography tandem mass spectrometry. These alkaloids can be classified into two subgroups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two subgroup alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by ultrahigh-performance liquid chromatography tandem mass spectrometry. The limit of detection was defined as the signal-to-noise ratio equal to 3 : 1. Limits of detection of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements.

Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance

Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR) for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3)-C(sp2) bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM) calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones.