Separation of stereoisomers of 7-oxa-bicyclo[2.2.1]heptene sulfonate (OBHS), a Selective Estrogen Receptor Modulator (SERM), via chiral stationary phases using SFC/UV and SFC/MS.

The enantiomeric separation of a racemate of 7-oxa-bicyclo[2.2.1]heptene sulfonate (OBHS) derivatives, a Selective Estrogen Receptor Modulator (SERM), was obtained using supercritical fluid chromatography in tandem with UV and mass spectrometry (SFC/UV and SFC/MS, respectively). Supercritical CO2 modified with methanol or isopropyl alcohol was used with isopropylamine (IPAm), trimethylamine (TEA), or trifluoroacetic acid (TFA) as an additive to obtain the enantiomers separations. Both Chiralpak IC and IA were evaluated for the separation of enantiomers. Results showed enantiomers separation can be achieved in less than 5 min with a resolution greater than 1 and 0.9, respectively, for the different OBHS derivatives (compounds A and B) using supercritical CO2 modified with 40% isopropyl alcohol containing 0.25% IPAm and IC column applying isocratic conditions. Similar conditions were used with the semi-preparative Chiralpak IC column to isolate more than 50 mg of each enantiomer. SFC/MS and SFC/UV results showed pure enantiomers were isolated. Method development via SFC was much simpler than those reported in the literature using HPLC.

Biospecific isolation and characterization of angiogenesis-promoting ingredients in Buyang Huanwu decoction using affinity chromatography on rat brain microvascular endothelial cells combined with solid-phase extraction, and HPLC-MS/MS.

Buyang Huanwu decoction (BHD) was reported to exert angiogenesis-promoting effects, but its active ingredients remain unknown. In this study, we developed a method to screen potential angiogenesis-promoting compounds in BHD, which involved biospecific isolation using live rat brain microvascular endothelial cells (rBMECs) and characterization using solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Six compounds showed binding affinity to rBMECs and were further identified as 6-hydroxykaempferol-di-O-glucoside, paeoniflorin, calycosin-7-O-ß-D-glucoside, galloylpaeoniflorin, formononetin-7-O-ß-D-glucoside, and (3R)-7,2'-hydroxy-3',4'-dimethoxy-isoflavan. The results indicated that five of them except 6-hydroxykaempferol-di-O-glucoside showed a protective effect against oxygen glucose deprivation/reperfusion injury in rBMECs and upregulated the secretion of vascular endothelial growth factor and basic fibroblast growth factor, suggesting a mechanism underlying their angiogenic activity. Our findings suggest that biospecific live cell-based isolation combined with SPE and HPLC-MS/MS is an effective method for screening potential bioactive components in traditional Chinese medicines.

Nine new compounds from the whole plants of Rehmannia chingii.

Nine new compounds, together with 16 known analogs, were isolated from the whole plants of Rehmannia chingii. The structures of compounds 1-9 were elucidated on the basis of their spectroscopic data and chemical evidence. In addition, the new compounds were tested for their hepatoprotective activities against APAP-induced HepG2 cell damage and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line. Compounds 2 and 5 exhibited pronounced hepatoprotective activities against APAP-induced HepG2 cell damage at a concentration of 10 µM, and compounds 4 and 9 showed moderate inhibitory activity against microglial inflammation factor with IC50 values of 3.51 and 7.11 µM, respectively.

Haliclonadiamine Derivatives and 6-epi-Monanchorin from the Marine Sponge Halichondria panicea Collected at Iriomote Island.

Four new haliclonadiamine analogues, (10Z,12E)-haliclonadiamine (1), (10E,12Z)-haliclonadiamine (2), and halichondriamines A (3) and B (4), were isolated from the Okinawan marine sponge Halichondria panicea together with haliclonadiamine (5) and papuamine (6). The structures of 1-4 were elucidated on the basis of their spectroscopic data by comparisons with those for 5 and 6. Further separation of the remaining fraction led to the isolation of a new bicyclic guanidine alkaloid, 6-epi-monanchorin (7), along with monanchorin (8). Compound 7 is the epimer of 8 at the 6 position. Compounds 1-6 inhibited the growth of Mycobacterium smegmatis with inhibition zones of 12, 7, 8, 7, 16, and 12 mm at 10 µg/disc, respectively. Compounds 2-4 exhibited weak cytotoxicities against the Huh-7 (hepatoma) human cancer cell line and were 2-fold less active than 5 and 6. Compounds 7 and 8 were not active against M. smegmatis at 20 µg/disc or the cancer cell line at 10 µM.

Peloruside A: a lead non-taxoid-site microtubule-stabilizing agent with potential activity against cancer, neurodegeneration, and autoimmune disease.

Covering: 2000 up to 2016Peloruside A, a macrocyclic secondary metabolite from a New Zealand marine sponge, Mycale hentscheli, has shown potent antiproliferative activity in cultured cancer cells as well as inhibitory effects on tumor growth in mouse models. The compound also has promising effects against cell models of neurodegenerative and autoimmune diseases. In mechanistic studies, peloruside A shares with paclitaxel (Taxol®) the ability to stabilize microtubules by binding to ß-tubulin. Peloruside A, however, occupies a unique external site on ß-tubulin that does not overlap the classical taxoid site that is located on the inside of the microtubule. As such, peloruside A has been of central importance in defining a new microtubule-stabilizer binding site localized on the exterior surface of the microtubule that has led to increased interest in the design of an upscaled total synthesis of the natural product and its analogues. Here, we review advances in the biochemical and biological validation of peloruside A as an attractive therapeutic candidate for the treatment of cancer, neurodegeneration, and autoimmune disease.

Bioactive 7-Oxabicyclic[6.3.0]lactam and 12-Membered Macrolides from a Gorgonian-Derived Cladosporium sp. Fungus.

One new bicyclic lactam, cladosporilactam A (1), and six known 12-membered macrolides (2-7) were isolated from a gorgonian-derived Cladosporium sp. fungus collected from the South China Sea. Their complete structural assignments were elucidated by comprehensive spectroscopic investigation. Quantum chemistry calculations were used in support of the structural determination of 1. The absolute configuration of 1 was determined by calculation of its optical rotation. Cladosporilactam A (1) was the first example of 7-oxabicyclic[6.3.0]lactam obtained from a natural source. Compound 1 exhibited promising cytotoxic activity against cervical cancer HeLa cell line with an IC50 value of 0.76 µM.

Relative and absolute structure of phomolide C.

Phomolide C (1) was isolated from a fungus Diaporthe sp. being found at Shirakami mountainous area. Although only the planar structure of 1 has been known, our detailed NMR spectroscopic analysis and ECD studies revealed its both relative and absolute configuration.

Deacetyl-mycoepoxydiene, isolated from plant endophytic fungi Phomosis sp. demonstrates anti-microtubule activity in MCF-7 cells.

Deacetyl-mycoepoxydiene (DM), a novel secondary metabolite produced by the plant endophytic fungi Phomosis sp., induced the reorganization of cytoskeleton in actively growing MCF-7 cells by promoting polymerization of tubulin. DM could induce cell cycle arrest at G2/M in MCF-7 cells. Additionally, DM-induced apoptosis was characterized with up-regulating caspase-3, Bax, caspase-9, parp, and p21 while down-regulating Bcl-2 activation. DM conferred dose- and time-dependent inhibitory effects upon cell proliferation of MCF-7 cells both in cultured cells and nude mice with human breast carcinoma xenografts. The results obtained from these in vitro and in vivo models provide new data revealing the potential for DM as a novel microtubule inhibitor.

Important role of SUMOylation of Spliceosome factors in prostate cancer cells.

Sentrin/SUMO (small ubiquitin-like modifier)-specific proteases (SENPs) have been implicated in the development of prostate cancer. However, due to the low abundance of SUMO-modified proteins and high activity of SENPs, the SUMO substrates affected by SENPs in prostate cancer cells are largely unknown. Here, we identified SI2, a novel cell-permeable SENP-specific inhibitor, by high-throughput screening. Using SI2 as a way of inhibiting the activity of SENPs and the SUMO stably transfected PC3 cells as a prostate cancer model, in combination with the stable isotope labeling with amino acids (SILAC) quantitative proteomic technique, we identified more than 900 putative target proteins of SUMO, in which 231 proteins were further subjected to bioinformatic analysis. In the highly enriched spliceosome pathway, we validated that USP39, HSPA1A, and HSPA2 were novel target proteins of SUMO. Furthermore, we demonstrated that K6, K16, K29, K51, and K73 were the SUMOylation sites of USP39. Mutation of these SUMO modification sites of USP39 further promoted the proliferation-enhancing effect of USP39 on prostate cancer cells. This study provides the SUMOproteome of PC3 cells and reveals that SUMOylation of spliceosome factors may be implicated in the pathogenesis of prostate cancer. Optimization of SI2 for isotype-specific SENP inhibitors warrants further investigation.

Myrotheciumones: bicyclic cytotoxic lactones isolated from an endophytic fungus of Ajuga decumbens.

Two new bicyclic lactones, myrotheciumones A (1) and B (2) which possessed a rare ring-fusion system were isolated from Myrothecium roridum (M. roridum), an endophytic fungus of the medicinal herb plant Ajuga decumbens (A. decumbens) via an in vitro cytotoxicity assay. Structures were deduced from 1D and 2D NMR (Nuclear magnetic resonance) data. Myrotheciumone A's in vitro cytotoxicity and apoptotic activity were evaluated and myrotheciumone A was shown to exert cytotoxicity via inducing apoptosis in cancer cell line.

A novel 6-hydroxy-8,11,11-trimethyl-bicyclo[7.2.0]undec-4-ene-4-carboxylic acid: a potent antioxidant agent from Iphiona scabra.

A novel 6-hydroxy-8,11,11-trimethyl-bicyclo[7.2.0]undec-4-ene-4-carboxylic acid 1 has been isolated from leaves of Iphiona scabra DC. Its structure has been established on the basis of chemical and physical evidence (IR, ¹H NMR, ¹³C NMR, and MS) and further confirmed by single-crystal X-ray diffraction study. The in vitro antioxidant activities of isolated compound 1 and extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl method.

Tubulin inhibitors from an endophytic fungus isolated from Cedrus deodara.

From an endophytic fungus, a close relative of Talaromyces sp., found in association with Cedrus deodara, four compounds including two new ones (2 and 4) were isolated and characterized. The structures of two compounds (1 and 4) were confirmed by X-ray crystallography. The compounds displayed a range of cytotoxicities against human cancer cell lines (HCT-116, A-549, HEP-1, THP-1, and PC-3). All the compounds were found to induce apoptosis in HL-60 cells, as evidenced by fluorescence and scanning electron microscopy studies. Also, the compounds caused significant microtubule inhibition in HL-60 cells.

Two new compounds from Senecio cannabifolius.

Chemical investigation of the water extracts from the Senecio cannabifolius Less. led us to find two new compounds (1 and 2), along with 12 known compounds (3-14). The two new compounds were determined as (E, 4R)-4-hydroxy-4,5,5-trimethyl-3-(3-oxobut-1-enyl)cyclohex-2-enone (1) and (E)-4-((1S, 3R, 4R)-1-hydroxy-4,5,5-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl)but-1-en-3-o-ne (2), respectively. The structures of other compounds were elucidated by extensive analysis of spectral data and in comparison with the literature values. Compounds 1 and 2 were evaluated for inhibitory activity against lipopolysaccharide-induced NO production in RAW 264.7 macrophages, and compound 1 showed potent inhibitory activity with IC(50) value of 30.65 µM.

Structure-activity studies of the pelorusides: new congeners and semi-synthetic analogues.

Two new peloruside congeners (3 and 4) were isolated from wild and aquacultured collections of the New Zealand marine sponge Mycale hentscheli. Small-scale reactions on peloruside A (1) have been performed, which along with the isolation of 3 and 4, give further insight into the bioactive pharmacophore of 1.

New bicyclotridecane C15 nonterpenoid bromoallenes from Laurencia marilzae.

Nonterpenoid bromoallenes possessing a novel skeleton that incorporates an unprecedented [5.5.1]bicyclotridecane ring system, marilzabicycloallenes A-D (1-4), were isolated from specimens of Laurencia marilzae collected on the Canary Islands. The framework of these metabolites strongly reinforces Braddock's hypothesis concerning the biosynthesis via electrophilic bromination of the obtusallene family.

In vitro activity of hypnophilin from Lentinus strigosus: a potential prototype for Chagas disease and leishmaniasis chemotherapy

Hypnophilin and panepoxydone, terpenoids isolated from Lentinus strigosus, have significant inhibitory activity onTrypanosoma cruzi trypanothione reductase (TR). Although they have similar TR inhibitory activity at 10 μg/mL (40.3 μM and 47.6 μM for hypnophilin and panepoxydone, respectively; ~100 percent), hypnophilin has a slightly greater inhibitory activity (~71 percent) on T. cruzi amastigote (AMA) growth in vitro as well as on in vitro phytohemagglutinin (PHA)-induced peripheral blood mononuclear (PBMC) proliferation (~70 percent) compared to panepoxydone (69 percent AMA inhibition and 91 percent PBMC inhibition). Hypnophilin and panepoxydone at 1.25 μg/mL had 67 percent inhibitory activity onLeishmania (Leishmania) amazonensis amastigote-like (AMA-like) growth in vitro. The panepoxydone activity was accompanied by a significant inhibitory effect on PHA-induced PBMC proliferation, suggesting a cytotoxic action. Moreover, incubation of human PBMC with panepoxydone reduced the percentage of CD16+ and CD14+ cells and down-regulated CD19+, CD4+ and CD8+ cells, while hypnophilin did not alter any of the phenotypes analyzed. These data indicate that hypnophilin may be considered to be a prototype for the design of drugs for the chemotherapy of diseases caused by Trypanosomatidae.

Abyssomicin I, a modified polycyclic polyketide from Streptomyces sp. CHI39.

Abyssomicin I (1), a new modified polycyclic polyketide, was isolated from the culture extract of a soil-derived Streptomyces sp. The structure of 1 was elucidated by interpretation of NMR and other spectroscopic data. The stereochemistry of the new compound was assigned by NOE analysis, chemical derivatization, and application of the modified Mosher method. While 1 was inactive against bacteria and yeasts, the oxidized derivative 7 showed weak activities against gram-positive bacteria. Compounds 1 and 7 exhibited inhibitory effects on tumor cell invasion with IC(50) values of 11 and 0.21 µM, respectively.

Microtubule-stabilizing drugs from marine sponges: focus on peloruside A and zampanolide.

Marine sponges are an excellent source of bioactive secondary metabolites with potential therapeutic value in the treatment of diseases. One group of compounds of particular interest is the microtubule-stabilizing agents, the most well-known compound of this group being paclitaxel (Taxol), an anti-cancer compound isolated from the bark and leaves of the Pacific yew tree. This review focuses on two of the more recent additions to this important class of drugs, peloruside A and zampanolide, both isolated from marine sponges. Peloruside A was isolated from Mycale hentscheli collected in New Zealand coastal waters, and it already shows promising anti-cancer activity. Two other potent bioactive compounds with different modes of action but isolated from the same sponge, mycalamide A and pateamine, will also be discussed. The fourth compound, zampanolide, most recently isolated from the Tongan sponge Cacospongia mycofijiensis, has only recently been added to the microtubule-stabilizing group of compounds, and further work is in progress to determine its activity profile relative to peloruside A and other drugs of this class.

Crassocolides G-M, cembranoids from the Formosan soft coral Sarcophyton crassocaule.

Seven new polyoxygenated cembranoids possessing an alpha-methylene-gamma-lactone group, crassocolides G-M (1-7, resp.), have been isolated from the AcOEt extract of the Formosan soft coral Sarcophyton crassocaule. The structures of compounds 1-7 were established by detailed spectroscopic analyses, including 2D-NMR spectroscopy ((1)H,(1)H-COSY, HMQC, HMBC, and NOESY), while the absolute configuration of 1 was determined using a modified reaction of Mosher's method. The cytotoxicity of compounds 1-7 against a limited panel of cancer cell lines was also determined.