Active Components from Cassia abbreviata Prevent HIV-1 Entry by Distinct Mechanisms of Action.

Cassia abbreviata is widely used in Sub-Saharan Africa for treating many diseases, including HIV-1 infection. We have recently described the chemical structures of 28 compounds isolated from an alcoholic crude extract of barks and roots of C. abbreviata, and showed that six bioactive compounds inhibit HIV-1 infection. In the present study, we demonstrate that the six compounds block HIV-1 entry into cells: oleanolic acid, palmitic acid, taxifolin, piceatannol, guibourtinidol-(4α→8)-epiafzelechin, and a novel compound named as cassiabrevone. We report, for the first time, that guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone inhibit HIV-1 entry (IC50 of 42.47 µM and 30.96 µM, respectively), as well as that piceatannol interacts with cellular membranes. Piceatannol inhibits HIV-1 infection in a dual-chamber assay mimicking the female genital tract, as well as HSV infection, emphasizing its potential as a microbicide. Structure-activity relationships (SAR) showed that pharmacophoric groups of piceatannol are strictly required to inhibit HIV-1 entry. By a ligand-based in silico study, we speculated that piceatannol and norartocarpetin may have a very similar mechanism of action and efficacy because of the highly comparable pharmacophoric and 3D space, while guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone may display a different mechanism. We finally show that cassiabrevone plays a major role of the crude extract of CA by blocking the binding activity of HIV-1 gp120 and CD4.

Asperochratides A-J, Ten new polyketides from the deep-sea-derived Aspergillus ochraceus.

Ten new C9 polyketides (asperochratides A-J, 1-10) and 14 known miscellaneous compounds (11-24) were isolated from the deep-sea-derived fungus Aspergillus ochraceus. Structures of the new compounds were elucidated by extensive spectroscopic analyses, modified Mosher's method, Mo2(OAc)4 induced circular dichroism (ICD) experiments, and ECD calculations. Structurally, compounds 1-11 and 16-18 share the same polyketide origin of the skeleton and belong to aspyrone co-metabolites. All isolates were tested for cytotoxic, anti-food allergic, anti-H1N1 virus, anti-microbe, and anti-inflammatory activities in vitro. Results showed that compounds 5-8 and 13-17 exerted significant cytotoxic effects on BV-2 cell line, and compound 16 showed the potential of anti-inflammatory activities.

Prenylated Acylphloroglucinols from Hypericum faberi.

The isolation and structure elucidation of six new prenylated acylphloroglucinols, faberiones A-F, from the whole plant of Hypericum faberi is reported. Faberiones A-D (1-4) share a rare styrene substituent and may be biosynthetically generated via further acylation of the acylphloroglucinols. By analyzing the MS and NMR data, the structures of the new isolates were established. Faberiones B (2) and C (3) showed moderate cytotoxicity against the pancreatic cell line (PANC-1) with IC50 values of 6.2 and 9.0 µM, respectively.

Attenuation of allergic responses following treatment with resveratrol in anaphylactic models and IgE-mediated mast cells.

Resveratrol exists widely in plant species and has a variety of anti-oxidant, anti-inflammatory, and immunomodulatory properties. However, there have been few reports regarding its anti-food allergic activity. In this study, we demonstrated that resveratrol (isolated from Abies georgei) could decrease the release of ß-hexosaminidase and histamine in rat basophilic leukemia-2H3 cells. Resveratrol was not only found to suppress the development of diarrhea, up-regulate the rectal temperature of ovalbumin-allergic mice, and decrease the serum level of specific immunoglobulin E, mouse mast cell protease-1 and histamine, but also found to decrease the population of dendritic cells, B cells and mast cells of ovalbumin -allergic mice in the spleen or mesenteric lymph node. Furthermore, resveratrol inhibited the release of ß-hexosaminidase and histamine in bone marrow-derived cells and alleviated mast cell-mediated passive cutaneous anaphylaxis reactions. These findings indicated that resveratrol isolated from Abies georgei might have the potential to alleviate food hypersensitivity or allergic disease.

[Chemical constituents from ethyl acetate-soluble extraction of Valeriana jatamansi].

Application of a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, macroporous adsorbent resin, and reversed-phase HPLC, led to the isolation of 173 compounds including irdidoids, monoterpenes, sesquiterpenes, triterpenes, lignans, flavonoids, and simple aromatic derivatives from the ethyl acetate-soluble fraction of the whole plants of Valeriana jatamansi(Valerianaceae), and their structures were elucidated by spectroscopic methods including 1D, 2D NMR UV, IR, and MS techniques. Among them, 77 compounds were new. In previous reports, we have described the isolation, structure elucidation, and bioactivities of 68 new and 25 known compounds. As a consequence, we herein reported the isolation and structure elucidation of the remaining 9 new and 71 known compounds, the structure revision of valeriotriate A(8a), as well as cytotoxicity of some compounds.

Saccharopolytide A, a new cyclic tetrapeptide with rare 4-hydroxy-proline moieties from the deep-sea derived actinomycete Saccharopolyspora cebuensis MCCC 1A09850.

A genome mining analysis on the deep-sea derived actinomycete Saccharopolyspora cebuensis MCCC 1A09850 indicated its potential to produce polypeptides. Accordingly, a systematic chemical investigation was conducted, which resulted in the isolation of one new cyclic tetrapeptide (saccharopolytide A, 1) and two known polyketides (2, 3) along with six other miscellaneous compounds (4‒9). Mainly by analysis of the 1D, 2D NMR and MS data, the chemical structure of saccharopolytide A was established as cyclo-(l-Leu-4-hydroxy-l-Pro-l-Phe-4-hydroxy-l-Pro). All isolates were evaluated for anti-allergic and anti-tumor bioactivities. Indol-3-carbaldehyde (4) showed weak anti-allergic effect with IC50 value of 55.75 µg/mL. And 2 showed weak anti-proliferative activity against Hela and H1299 tumor cell lines. Our results consolidate the potential of deep-sea-derived microorganisms to produce structurally interesting compounds.

Three minor valepotriate isomers from Valeriana jatamansi and their cytotoxicity.

Three new minor valepotriate isomers, jatamanvaltrates Z1 (1), Z2 (2), and Z3 (3), have been isolated from the whole plants of Valeriana jatamansi (syn. Valeriana wallichii.). Their structures were elucidated by extensive spectroscopic analysis, especially 2D NMR and ESI-MS/MSn. All isolated compounds displayed moderate cytotoxicity against the lung adenocarcinoma (A549), metastatic prostate cancer (PC-3 M), colon cancer (HCT-8), and hepatoma (Bel7402) cell lines with IC50 values of 2.8-8.3 µM.

Celastrol inhibits prostaglandin E2-induced proliferation and osteogenic differentiation of fibroblasts isolated from ankylosing spondylitis hip tissues in vitro.

BACKGROUND: Heterotopic ossification on the enthesis, which develops after subsequent inflammation, is one of the most distinctive features in ankylosing spondylitis (AS). Prostaglandin E2 (PGE-2) serves as a key mediator of inflammation and bone remodeling in AS. Celastrol, a well-known Chinese medicinal herb isolated from Tripterygium wilfordii, is widely used in treating inflammatory diseases, including AS. It has been proven that it can inhibit lipopolysac-charide-induced expression of various inflammation mediators, such as PGE-2. However, the mechanism by which celastrol inhibits inflammation-induced bone forming in AS is unclear. OBJECTIVE: To investigate whether celastrol could inhibit isolated AS fibroblast osteogenesis induced by PGE-2. METHODS: Hip synovial tissues were obtained from six AS patients undergoing total hip replacement in our hospital. Fibroblasts were isolated, primarily cultured, and then treated with PGE-2 for osteogenic induction. Different doses of celastrol and indometacin were added to observe their effects on osteogenic differentiation. Cell proliferation, osteogenic markers, alizarin red staining as well as the activity of alkaline phosphatase were examined in our study. RESULTS: Celastrol significantly inhibits cell proliferation of isolated AS fibroblasts and in vitro osteogenic differentiation compared with control groups in a time- and dose-dependent manner. CONCLUSION: Our results demonstrated that celastrol could inhibit isolated AS fibroblast proliferation and in vitro osteogenic differentiation. The interaction of PI3K/AKT signaling and Wnt protein may be involved in the process. Further studies should be performed in vivo and animal models to identify the potential effect of celastrol on the bone metabolism of AS patients.

[Secondary metabolites from a deep-sea-derived actinomycete Micrococcus sp. R21].

To investigate cytotoxic secondary metabolites of Micrococcus sp. R21, an actinomycete isolated from a deep-sea sediment (-6 310 m; 142 degrees 19. 9' E, 10 degrees 54. 6' N) of the Western Pacific Ocean, column chromatography was introduced over silica gel, ODS, and Sephadex LH-20. As a result, eight compounds were obtained. By mainly detailed analysis of the NMR data, their structures were elucidated as cyclo(4-hydroxy-L-Pro-L-leu) (1), cyclo(L-Pro-L-Gly) (2), cyclo( L-Pro-L-Ala) (3), cyclo( D-Pro-L-Leu) (4), N-ß-acetyltryptamine (5), 2-hydroxybenzoic acid (6), and phenylacetic acid (7). Compound 1 exhibited weak cytotoxic activity against RAW264. 7 cells with IC50 value of 9.1 µmol x L(-1).

Mass spectrometric profiling of valepotriates possessing various acyloxy groups from Valeriana jatamansi.

Valepotriates, plant secondary metabolites of the family Valerianaceae, contain various acyloxy group linkages to the valepotriate nucleus and exhibit significant biological activities. Identification of valepotriates is important to uncover potential lead compounds for the development of new sedative and antitumor drugs. However, making their structure elucidation by nuclear magnetic resonance (NMR) experiments is too difficult to be realized because of the overlapped carbonyl carbon signals of acyloxy groups substituted at different positions. Thus, the mass spectrometric profiling of these compounds in positive ion mode was developed to unveil the exact linkage of acyloxy group and the core of valepotriate. In this study, electrospray ionization tandem multistage mass spectrometry (ESI-MS/MS(n)) in ion trap and collision-induced dissociation tandem MS were used to investigate the fragmentation pathways of four types of valepotriates in Valeriana jatamansi, including 5-hydroxy-5,6-dihydrovaltrate hydrin (5-hydroxy-5,6-dihydrovaltrate chlorohydrin), 5,6-dihydrovaltrate hydrin (5,6-dihydrovaltrate chlorohydrin), 5-hydroxy-5,6-dihydrovaltrate and valtrate hydrin (valtrate chlorohydrin). The high-resolution mass spectrum (HRMS) data of all the investigated valepotriates from quadrupole time-of-flight MS/MS were used as a supportive of the fragmentation rules we hypothesized from ion-trap stepwise MS(n). As a result, the loss sequence of acyloxy groups and the abundance of key product ions, in combination with the characteristic product ions corresponding to the valepotriate nucleus, could readily differentiate the four different types of valepotriates. The summarized fragmentation rules were also successfully exploited for the structural characterization of three new trace valepotriates from V. jatamansi. The results indicated that the developed analytical method could be employed as a rapid, effective technique for structural characterization of valepotriates, especially for the trace compounds that could not be identified by NMR techniques. This study may also arouse interest for further structural analysis of other valepotriate-containing type herbal medicines.

Chemical constituents of Abies fabri.

Systematic phytochemical investigations on Abies fabri resulted in the isolation of 94 compounds, consisting of 68 terpenoids, six lignans, seven flavonoids, and 13 other miscellaneous chemical constituents. Their structures were elucidated on the basis of spectroscopic methods, and the absolute configurations of three of these previously unknown compounds were determined by Cu-Kα X-ray crystallographic analysis. Twelve previously unreported compounds, one artifact, and one potential artifact were identified, including six triterpenoids, four diterpenoids, two sesquiterpenoids, one lignan, and one phenol. 23-Hydroxy-3-oxolanosta-8,24-dien-26,23-olide showed weak cytotoxic activity against A549 and THP-1 cells with the IC50 values of 5.3 and 5.1 µM, respectively.

Three decomposition products of valepotriates from Valeriana jatamansi and their cytotoxic activity.

Three new decomposition products of valepotriates, valtrals A-C (1-3), and two known products, baldrinal and homobaldrinal, are formed during the isolation procedure of the ethanol extract of the whole plants of Valeriana jatamansi. Their structures were determined by spectroscopic methods including IR, MS, 1D, and 2D NMR experiments. Compounds 1-3 showed selective cytotoxicity against metastatic prostate cancer (PC-3M) and colon cancer (HCT-8) cell lines.

Minor valepotriates from Valeriana jatamansi and their cytotoxicity against metastatic prostate cancer cells.

Ten new valepotriates, jatamanvaltrates P-Y (1-10) and a known one, nardostachin (11), have been isolated from the whole plants of Valeriana jatamansi. The structures of the new compounds were determined by detailed spectroscopic data analysis. The isolated compounds were evaluated for cytotoxic activity against PC-3M cells, and a structure-activity relationship was examined for all the valepotriates isolated from V. jatamansi. The results highlighted the structure-activity relationship importance of the C-3-C-4 double bond, the oxirane ring, and the 10-chlorine in the valepotriates.

Chemical constituents of Abies nukiangensis.

During a survey on chemical constituents of Abies nukiangensis, seven previously unreported compounds, including six triterpenes (1-6) and one phenol (7) were isolated and characterized, together with 37 known miscellaneous chemical constituents. The structures of compounds 1-7 were established mainly by extensive analysis of the 1D and 2D NMR, as well as HRMS data. The absolute configurations of compounds 1 and 8 were confirmed unambiguously by the Cu-Kα X-ray crystallography. Compounds 3 and 8-10 showed significant anti-hepatitis C virus effects with EC50 values of 3.73, 2.67, 1.33 and 2.25µM, respectively.

Chemical constituents of Abies delavayi.

Systematic phytochemical investigations on Abies delavayi afforded 110 compounds, including 49 terpenoids, 13 lignans, 20 flavonoids, three coumarins, and 25 other chemical constituents. By detailed analysis of one- and two-dimensional NMR spectroscopic and high-resolution mass spectrometric data, 10 previously unreported compounds were identified: they comprised three sesquiterpenoids, two diterpenoids, one triterpenoid, one monoterpenoid, one flavonoid, and two phenols. These 10 compounds and some previously known ones were subjected to two cytotoxic bioassays against three human tumor cell lines and NO production inhibition on RAW264.7 macrophages, respectively. (25R)-24,25-Dihydroabieslactone had the strongest cytotoxic activity against Colo-205 cells with an IC50 value of 19.0±3.7µg/mL. (+)-T-cadinol, 8,11,13-abietatrien-15-ol-18-yl acetate, 18-acetoxy-13-epi-manool, imperatorin, bergapten, and 5,7-O-dimethyl poriol exhibited weak inhibitory activity against LPS-induced NO production in RAW264.7 macrophages with IC50 values of approximately 50µg/mL.

Cytotoxic triterpenoids from Abies recurvata.

Nine triterpenoids (neoabiestrines A-I, 1-9) including six rearranged lanostanes (1-6) and a rare cycloart-7-ene (7) were isolated from Abies recurvata together with ten known compounds. Their structures were determined by detailed analysis of NMR and MS spectroscopic data. The absolute configurations of 1 and 8 were determined by Cu-Ka X-ray crystallography. Compound 6 showed potent anti-proliferative effect against THP-1 tumor cells with an IC(50) value of 17.8 µg/mL.

New monoterpenes, diterpenes, and lignans from Abies recurvata.

From the aerial part of Abies recurvata, 62 miscellaneous chemical constituents were isolated including 6 new and 56 known ones. The new compounds comprised three monoterpenes, two diterpenes, and one lignan. Their chemical structures were characterized on the basis of various spectroscopic techniques. Dihydrodehydrodiconiferyl alcohol (35) showed the strongest inhibitory effects against lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells with an IC50 value of 66.4 µM.

Sesquiterpenoids and triterpenoids from Abies holophylla and their bioactivities.

Six previously unreported and 11 known terpenoids were isolated from Abies holophylla. The structures of the six compounds were established as two unusual bisabolane sesquiterpenoids, three nortriterpenoids, and one 3,4-seco-triterpenoid based on the detailed analysis of their 1D and 2D NMR spectroscopic data. In addition, electronic circular dichroism (ECD) calculations and molecular orbital (MO) analysis were used to assign the absolute configuration of one bisabolane sesquiterpenoid, abiesesquine A. Abiesesquine A showed the strongest inhibitory effects against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages with an IC(50) value of 113.1 µM. Lanosta-7,9(11),24-trien-26-oic acid showed potent cytotoxic activity against COLO-205, LOVO, and QGY-7703 tumor cells with IC(50) values of 0.9, 4.2, and 2.0 µM, respectively. (23R,25R)-3,4-seco-9ßH-Lanosta-4(28),7-dien-26,23-olid-3-oic acid, exhibited a significant antiproliferation effect against A549 cells (IC(50)=14.7 µM).

Sesquiterpenoids from Inula racemosa Hook. f. inhibit nitric oxide production.

A novel trinorsesquiterpene (1), three new (2-4), and 10 known sesquiterpenes were isolated from the roots of Inula racemosa Hook. f. The structures and absolute configurations of the new sesquiterpenes were elucidated by extensive spectroscopic and computational methods. All compounds were evaluated for their inhibition of LPS-induced nitric oxide production in RAW264.7 macrophages, and the results indicated that compounds 9, 12, and 13 moderately inhibited nitric oxide production with IC50 values of 7.39 ± 0.36, 6.35 ± 0.26, and 5.39 ± 0.18 µM, respectively.

Phenolic compounds of Abies nephrolepis and their NO production inhibitory activities.

Two new, i.e., 1 and 2, and 69 known phenolics were isolated from the aerial parts of Abies nephrolepis. These chemical constituents included 22 lignans, 30 flavonoids, and 19 other phenols. Their structures were determined mainly by analysis of the 1D- and 2D-NMR spectroscopic data. All the 71 isolates were evaluated for their inhibitory activities against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 macrophages. Compound 1 exhibited a potent effect with an IC(50) value of 13.7 µg/ml.