Unusual polyoxygenated casbane diterpenoids from the South China Sea soft coral Sinularia erecta.

A further systematically chemical investigation of the South China Sea soft coral Sinularia erecta led to the discovery of two rare casbane diterpenoids with an uncommon 8,10-peroxide bridge, sinuereperoxides B (1) and C (2), five new casbanes with other oxygenated patterns (3-7), and seven known casbanes (8-14). The structures and absolute configurations of 1-7 were established by extensive spectroscopic data analyses, X-ray diffraction analysis, and/or quantum chemical calculations. In bioassay, compounds 2, 7, 11 and 12 exhibited considerable anti-inflammatory activity by the inhibition of TNF-α release, with IC50 values of 33.8 µM, 5 µM, 9.9 µM and 8 µM.

New Rare Ent-Clerodane Diterpene Peroxides from Egyptian Mountain Tea (Qourtom) and Its Chemosystem as Herbal Remedies and Phytonutrients Agents.

Genus Stachys, the largest genera of the family Lamiaceae, and its species are frequently used as herbal teas due to their essential oils. Tubers of some Stachys species are also consumed as important nutrients for humans and animals due to their carbohydrate contents. Three new neo-clerodane diterpene peroxides, named stachaegyptin F-H (1, 2, and 4), together with two known compounds, stachysperoxide (3) and stachaegyptin A (5), were isolated from Stachys aegyptiaca aerial parts. Their structures were determined using a combination of spectroscopic techniques, including HR-FAB-MS and extensive 1D and 2D NMR (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOESY) analyses. Additionally, a biosynthetic pathway for the isolated compounds (1-5) was discussed. The chemotaxonomic significance of the isolated diterpenoids of S. aegyptiaca in comparison to the previous reported ones from other Stachys species was also studied.

Parameters of the Mouse Embryo Assay that affect detection of peroxides in mineral oil.

RESEARCH QUESTION: Can culture conditions influence the sensitivity of a Mouse Embryo Assay and its potential to detect peroxide-related toxicity in mineral oil samples? DESIGN: Protein type and concentration, embryo density and culture dish design were selected as the variables in the culture system with the potential to influence the assay's sensitivity. Fresh 1-cell mouse embryos were cultured under mineral oil samples with known peroxide concentrations. Protein type (human serum albumin [HSA] + α/ß-Globulins versus HSA versus bovine serum albumin [BSA]), concentration (5 mg/ml versus 0.5 mg/ml), embryo density (25 versus 3 µl/embryo) and culture dish (Petri versus micro-well dish) were adjusted to define the culture conditions with the highest sensitivity. RESULTS: High concentrations of peroxides can be easily detected by current quality control standards. However, for oil samples with a lower concentration of peroxides, supplementing the culture medium with 5 mg/ml of HSA + alpha/beta-globulins or with HSA resulted in an increased detection of embryo toxicity compared with when BSA was used as the protein supplement. The sensitivity of the assay was greatly reduced when embryos were cultured in groups and when certain micro-well dishes were used. CONCLUSIONS: Current quality control protocols may not be sensitive enough to identify low concentrations of peroxides, which, if undetected, can increase over time and become potentially harmful during gamete and embryo culture. The different parameters established in this study allow the sensitivity of the Mouse Embryo Assays to be optimized to specifically detect peroxides in mineral oil samples prior to their release into the market and their broad use in human IVF.

Bioactive Dimeric Abietanoid Peroxides from the Bark of Cryptomeria japonica.

Three new dimeric abietane-type diterpenoids, abieta-6,8,11,13-tetraen-12-yl 12-hydroxyabieta-8,11,13-trien-7α-yl peroxide (1), abieta-6,8,11,13-tetraen-12-yl 12-hydroxyabieta-8,11,13-trien-7ß-yl peroxide (2), and 12-hydroxyabieta-8,11,13-trien-7ß-yl 7-oxoabieta-5,8,11,13-tetraen-12-yl peroxide (3), together with four known abietane-type diterpenoids (4-7) were isolated from the methanol extract of the bark of Cryptomeria japonica. Their structures were elucidated on the basis of spectroscopic analysis and comparison of NMR data with those of known analogues. At a concentration of 50 µM, compounds 1, 2, and 3 showed 26.2%, 23.6%, and 35.7% inhibition towards xanthine oxidase enzyme, respectively. In addition, compound 3 also showed 24.9% inhibition toward angiotensin-converting enzyme (ACE).

Bioactive compounds from sclerotia extract of Poria cocos that control adipocyte and osteoblast differentiation.

Poria cocos Wolf confers edible sclerotia also known as 'Indian bread' in North America, that have been used for the treatment of various diseases in Asian countries. As part of our ongoing aim to identify biologically new metabolites from Korean edible mushrooms, we investigated the ethanol (EtOH) extract of the sclerotia of P. cocos by applying a comparative LC/MS- and bioassay-based analysis approach, since the EtOH extract reciprocally regulated adipocyte and osteoblast differentiation in mouse mesenchymal stem cells (MSCs). Bioassay-based analysis of the EtOH extract led to the successful isolation of two sterols, ergosterol peroxide (1) and 9,11-dehydroergosterol peroxide (2); three diterpenes, dehydroabietic acid (3), 7-oxocallitrisic acid, (4) and pimaric acid (5); and two triterpenes, dehydroeburicoic acid monoacetate (6) and eburicoic acid acetate (7) from the active hexane-soluble fraction. The isolated compounds (1-7) were examined for their effects on the regulation of MSC differentiation. The two sterols (1 and 2) were able to suppress MSC differentiation toward adipocytes. In contrast, the three diterpenes (3-5) showed activity to promote osteogenic differentiation of MSC. These findings demonstrate that the EtOH extract of P. cocos sclerotia is worth consideration as a new potential source of bioactive compounds effective in the treatment of osteoporosis in the elderly, since the extract contains sterols that inhibit adipogenic differentiation as well as diterpenes that promote osteogenic differentiation from MSCs.

Peroxy steroids derived from plant and fungi and their biological activities.

Peroxides represent a large and interesting group of biologically active natural compounds. All these metabolites contain a peroxide group (R-O-O-R). This review describes studies of more than 60 peroxides isolated from plants and fungi. Most of the plant peroxy steroids exhibit high antiprotozoal (Plasmodium) activity with a confidence of up to 95%, while steroids harvested from fungi show more antineoplastic activity with a confidence of up to 94%. In addition, more than 20 different activities of both groups of peroxides with a probability of 78 to 90% have also been predicted using computer program PASS.

New Cembranoids and a Biscembranoid Peroxide from the Soft Coral Sarcophyton cherbonnieri.

Six new cembranoids, cherbonolides A-E (1⁻5) and bischerbolide peroxide (6), along with one known cembranoid, isosarcophine (7), were isolated from the Formosan soft coral Sarcophyton cherbonnieri. The structures of these compounds were elucidated by detailed spectroscopic analysis and chemical methods. Compound 6 was discovered to be the first example of a molecular skeleton formed from two cembranoids connected by a peroxide group. Compounds 1⁻7 were shown to have the ability of inhibiting the production of superoxide anions and elastase release in N-formyl-methionyl-leucyl-phenyl-alanine/cytochalasin B (fMLF/CB)-induced human neutrophils.

The First Casbane Hydroperoxides EBC-304 and EBC-320 from the Australian Rainforest.

Investigation of the Australian rainforest plant Croton insularis led to isolation of the first casbane hydroperoxide diterpenes EBC-304 and EBC-320. Extensive DFT and electronic circular dichroism (ECD) calculations in combination with 2D NMR spectroscopy determined the absolute configurations. EBC-304 and EBC-320 both display significant cytotoxicity.

New antimalarial norterpene cyclic peroxides from Xisha Islands sponge Diacarnus megaspinorhabdosa.

Four new norterpene cyclic peroxides (1-4), together with three known norterpene cyclic peroxides were isolated from the Xisha Islands Sponge Diacarnus megaspinorhabdosa. Their structures were elucidated on the basis of spectroscopic analyses and comparison with the related model compounds. The compounds (1-7) were evaluated for the inhibitory activity against the malaria parasite Plasmodium falciparum, all of them showed significant antimalarial activity with IC50 values in the range of 1.6-8.6 µM.

Peroxide Natural Products from Plakortis zyggompha and the Sponge Association Plakortis halichondrioides-Xestospongia deweerdtae: Antifungal Activity against Cryptococcus gattii.

Cryptococcus gattii is a human pathogen and causative agent of a pernicious, sometimes fatal, disseminated fungal disease. Investigation of antifungal extracts of the marine sponge association Plakortis halichondrioides-Xestospongia deweerdtae and the sponge Plakortis zyggompha from the Bahamas led to the discovery and isolation of 6-epi-7,8-dihydroplakortide K (1), plakortide AA (2), and three new plakinic acids, N-P (4-6; unstable 1,2-dioxolanes bearing benzyl-substituted conjugated dienes), along with known plakinic acids L, K, and M.5 Chiroptical comparisons and DFT calculations of (13)C NMR chemical shifts were used to assign the absolute stereostructure of 4. The stereospecific base-promoted rearrangement-saponification of 1 to 10 was briefly investigated and showed tight kinetic control and stereospecific formation of the new C-2 stereocenter with inversion at C-3. Plakinic acid M and plakortides 9 and 11 exhibited antifungal activity against C. gattii (MIC90 = 2.4 to 36 µM), but plakinic acids N-P were inactive under the same conditions.

Analyzing cell physiology in C. elegans with fluorescent ratiometric reporters.

Ratiometric fluorescent reporters have recently emerged a new technique to non-invasively measure aspects of cell physiology such as redox status, calcium levels, energy production, and NADH levels. These reporters consist of either a single or pair of fluorophores along with specific modifications, such as the addition of a protein domain which binds to a metabolite of interest, thereby producing gradual alterations in fluorescence in response to changes in the measured parameter. Measurement of the changes in fluorescence produces a quantitative read-out of the cellular environment. While these reporters were initially developed to easily visualize and track changes in cultured cells, several groups have adapted these reporters to use in Caenorhabditis elegans which opens a new avenue through which to explore cell physiology during development or aging, in response to changes in external environment, or in response to genetic manipulation. These reporters have the advantage of being easily targeted to any part of the worm, and because C. elegans is transparent both the reporters and changes in their fluorescence can be clearly observed in vivo. Here we discuss the application of ratiometric reporters to C. elegans, and outline a method to quantitatively measure changes in intracellular peroxide levels using the HyPer ratiometric reporter. However, these principles can be applied to alternate ratiometric reporters which are designed to measure either other chemical species or other cellular parameters.

New Metabolites from the South China Sea Sponge Diacarnus megaspinorhabdosa.

Chemical investigation on CH2Cl2 extract of the marine sponge Diacarnus megaspinorhabdosa resulted in the isolation of two new farnesylacetone derivatives 1-2, a new γ-lactone 3, a known dinorditerpenone 4 and four known norsesterterpene peroxides 5-8. Their structures were elucidated by using one and two dimensional (1D and 2D)-NMR, high resolution-electrospray ionization (HR-ESI)-MS, and comparison with the literature. Compounds 1 and 2 were cis/trans-olefinic isomers and determined through nuclear Overhauser effect spectroscopy (NOESY) experiment. The absolute configuration of 3 was established by comparison of circular dichroism (CD) data with known lactones. The cytotoxic activities of the compounds were evaluated against five cancer cell lines, and compound 3 showed moderate cytotoxicity activities against cancer cell lines HeLa, H446, NCI-H460, SGC-7901 and MCF-7, with IC50 values in the range of 18.5 to 47.1 µM.

A novel C25 sterol peroxide from the endophytic fungus Phoma sp. EA-122.

A novel C25 sterol peroxide, phomasterol A (1), together with two known compounds (2-3), was isolated from the endophytic fungus Phoma sp. EA-122. The structure of phomasterol A (1) was elucidated by MS, 1D, and 2D NMR data analyses. Phomasterol A (1) was evaluated for its inhibitory activities against protein-tyrosine phosphatases MEG2 and PTP1Bc, showing moderate activities with identical IC50 values of 25 µM.

Endoperoxide polyketides from a Chinese Plakortis simplex: further evidence of the impact of stereochemistry on antimalarial activity of simple 1,2-dioxanes.

Chemical investigation of the organic extract obtained from the sponge Plakortis simplex collected in the South China Sea afforded five new polyketide endoperoxides (2 and 4-7), along with two known analogues (1 and 3). The stereostructures of these metabolites have been deduced on the basis of spectroscopic analysis and chemical conversion. The isolated endoperoxide derivatives have been tested for their in vitro antimalarial activity against Plasmodium falciparum strains, showing IC50 values in the low micromolar range. The structure-activity relationships were analyzed by means of a detailed computational investigation and rationalized in the light of the mechanism of action proposed for this class of simple antimalarials. The relative orientation of the atoms involved in the putative radical generation and transfer reaction was demonstrated to have a great impact on the antimalarial activity. The resulting 3D pharmacophoric model can be a useful guide to design simple and effective antimalarial lead compounds belonging to the class of 1,2-dioxanes.

Prenylated indolediketopiperazine peroxides and related homologues from the marine sediment-derived fungus Penicillium brefeldianum SD-273.

Three new indolediketopiperazine peroxides, namely, 24-hydroxyverruculogen (1), 26-hydroxyverruculogen (2), and 13-O-prenyl-26-hydroxyverruculogen (3), along with four known homologues (4-7), were isolated and identified from the culture extract of the marine sediment-derived fungus Penicillium brefeldianum SD-273. Their structures were determined based on the extensive spectroscopic analysis and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of compounds 1-3 was determined using chiral HPLC analysis of their acidic hydrolysates. Each of the isolated compounds was evaluated for antibacterial and cytotoxic activity as well as brine shrimp (Artemia salina) lethality.

Germacranolides and their diversity of Eupatorium heterophyllum collected in P. R. China.

Eight new hydroperoxides and a new enone of germacrane-type sesquiterpenoids were isolated from the aerial parts of eight different samples of Eupatorium heterophyllum DC. (Asteraceae) collected in P. R. China. The structures were determined based on spectroscopic analyses. Seven of the eight samples produced hiyodorilactone A as a major constituent, while one afforded neither hiyodorilactone nor hydroperoxide. The results indicated the presence of diversity within this species.

Ergosterols with rare peroxide, oxetane ring moiety, and a lactone ring from Aspergillus spectabilis and their immunosuppressive activities.

Ten ergostane-type steroids, including seven undescribed ones named spectasteroids A-G, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined based on HRESIMS, NMR, ECD calculations, and single-crystal X-ray diffraction analyses. Structurally, spectasteroid A was a unique example of aromatic ergostane-type steroid that featured a rare peroxide ring moiety; spectasteroid B contained a rare oxetane ring system formed between C-9 and C-14; and spectasteroid C was an unusual 3,4-seco-ergostane steroid with an extra lactone ring between C-3 and C-9. Spectasteroids F and G specifically showed inhibitory effects against concanavalin A-induced T lymphocyte proliferation and lipopolysaccharide-induced B lymphocyte proliferation, with IC50 values ranging from 2.33 to 4.22 µM. Spectasteroid F also showed excellent antimultidrug resistance activity, which remarkable enhanced the inhibitory activity of PTX on the colony formation of SW620/Ad300 cells.

Cyclic peroxides and analogs: Antibacterial, antimalarial, and cytotoxic marine products from Xisha sponge Diacarnus sp.

A chemical investigation of the dichloromethane extract from the Xisha sponge Diacarnus sp. revealed seven undescribed norterpene cyclic peroxides, named diacarperoxides T-Z, and five unreported related norterpenes, named diacarnoids E-I, and eleven previously reported compounds. The structures of these isolated compounds, including their absolute configurations, were elucidated based on extensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, Snatzke's method, [Rh2(OCOCF3)4]-induced ECD spectra, and modified Mosher's method. Bioassays were performed to assess the antibacterial activity against six pathogenic bacteria, cytotoxicities toward three cancer cell lines, and antimalarial activity against Plasmodium parasites. Most of the cyclic peroxides exhibited substantial antibacterial activity (MIC 1-8 µg/mL). Diacarperoxide W and nuapapuin A showed substantial antimalarial activity with IC50 values of 0.98 and 2.83 µM. Moreover, many compounds exhibited <50% cell survival rates, and IC50 values of 0.22-6.33 µM. The apoptosis assay showed that nuapapuin A induced cancer cell apoptosis in a dose-dependent manner.

Production of sulfate radical from peroxymonosulfate induced by a magnetically separable CuFe2O4 spinel in water: efficiency, stability, and mechanism.

A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe(2)O(4) spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe(2)O(4) showed higher activity and 30 times lower Cu(2+) leaching (1.5 µg L(-1) per 100 mg L(-1)) than a well-crystallized CuO at the same dosage. CuFe(2)O(4) maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe(2)O(4) was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe(2)O(4), the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide's surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS.

In vitro pharmacological and toxicological effects of norterpene peroxides isolated from the Red Sea sponge Diacarnus erythraeanus on normal and cancer cells.

Eight cyclic peroxide norterpenoids, compounds 1-8, have been isolated and characterized from the Red Sea sponge Diacarnus erythraeanus, including two new norsesterterpene derivatives (3, 4). Among these metabolites, (-)-muqubilin A (5) (nine cell lines analyzed) and the new compounds 3 and 4 (seven cell lines analyzed) displayed mean IC50 growth inhibitory concentrations in vitro of <10 µM, while the remaining compounds (1, 6-8) were inactive in these cancer cell lines. Compound 5 displayed no selectivity between normal and cancer cells in terms of in vitro growth inhibition. Quantitative video microscopy analysis carried out on (-)-muqubilin A-treated cells validated the data obtained by means of the MTT colorimetric assay, while flow cytometry analysis revealed ROS production but no induction of apoptosis in cancer cells.