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A novel approach to produce chiral diaryl sulfoxides from aryl benzyl sulfoxides and aryl bromides via an enantioselective arylation of aryl sulfenate anions is reported. A (JosiPhos)Pd-based catalyst successfully promotes the asymmetric arylation reaction with good functional group compatibility. A wide range of enantioenriched diaryl, aryl heteroaryl, and even diheteroaryl sulfoxides were generated. Many of the sulfoxides prepared herein would be difficult to prepare via classic enantioselective oxidation of sulfides, including Ph(Ph-d 5 )SO (90% ee, 95% yield). A DFT-based computational study suggested that chiral induction originates from two primary factors: (i) both a kinetic and a thermodynamic preference for oxidative addition that places the bromide trans to the JosiPhos-diarylphosphine moiety and (ii) Curtin-Hammett-type control over the interconversion between O- and S-bound isomers of palladium sulfenate species following rapid interconversion between re- and si-bound transmetalation products, re/si-Pd-OSPh (re/si-PdO-trans).

The combination of high speed autosampler technology and ultrafast chromatographic separations enables faster high throughput analysis. With an injection cycle time of 10.6 s, MISER (Multiple Injection in a Single Experimental Run) HPLC-MS analysis of a 96 well microplate can be completed in only 17min. As chromatographic separations in the sub 5s range become increasingly common, even faster autosamplers will be needed to realize further speed improvements in high throughput LC-MS analysis. Indeed with proper hardware sampling approaches, chromatographic analysis of microplates could approach speeds of spectrophotometric plate readers while maintaining the advantage of multicomponent detection and monitoring., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Chromatographic separation and analysis of complex mixtures of closely related species is one of the most challenging tasks in modern pharmaceutical analysis. In recent years, two-dimensional liquid chromatography (2D-LC) has become a valuable tool for improving peak capacity and selectivity. However, the relatively slow speed of chiral separations has limited the use of chiral stationary phases (CSPs) as the second dimension in 2D-LC, especially in the comprehensive mode. Realizing that the recent revolution in the field of ultrafast enantioselective chromatography could now provide significantly faster separations, we herein report an investigation into the use of ultrafast chiral chromatography as a second dimension for 2D chromatographic separations. In this study, excellent selectivity, peak shape, and repeatability were achieved by combining achiral and chiral narrow-bore columns (2.1 mm × 100 mm and 2.1 mm × 150 mm, sub-2 and 3 μm) in the first dimension with 4.6 mm × 30 mm and 4.6 mm × 50 mm columns packed with highly efficient chiral selectors (sub-2 μm fully porous and 2.7 μm fused-core particles) in the second dimension, together with the use of 0.1% phosphoric acid/acetonitrile eluents in both dimensions. Multiple achiral × chiral and chiral × chiral 2D-LC examples (single and multiple heart-cutting, high-resolution sampling, and comprehensive) using ultrafast chiral chromatography in the second dimension are successfully applied to the separation and analysis of complex mixtures of closely related pharmaceuticals and synthetic intermediates, including chiral and achiral drugs and metabolites, constitutional isomers, stereoisomers, and organohalogenated species.

Recent developments in fast chromatographic enantioseparations now make high throughput analysis of enantiopurity on the order of a few seconds achievable. Nevertheless, routine chromatographic determinations of enantiopurity to support stereochemical investigations in pharmaceutical research and development, synthetic chemistry and bioanalysis are still typically performed on the 5-20 min timescale, with many practitioners believing that sub-minute enantioseparations are not representative of the molecules encountered in day to day research. In this study we develop ultrafast chromatographic enantioseparations for a variety of pharmaceutically-related drugs and intermediates, showing that sub-minute resolutions are now possible in the vast majority of cases by both supercritical fluid chromatography (SFC) and reversed phase liquid chromatography (RP-LC). Examples are provided illustrating how such methods can be routinely developed and used for ultrafast high throughput analysis to support enantioselective synthesis investigations.

Imine-bond formation between chiral amines and commercially available 3-hydroxypyridine-2-carboxaldehyde (HCA) was exploited for rapid determination of stereochemical composition. Chiral supercritical fluid chromatography (SFC) screening of the derivatized imine compounds led to the elucidation of multiple combinations of mobile and stationary phases that gave resolution of all members of a series of chiral amines. The first eluting enantiomer was generally the derivative of the (R)-amine enantiomer across the series that was studied, indicating that the imine formed from the (S)-amine has more favorable interaction with the chiral stationary phase of the column. These conditions were then applied to more challenging compounds, namely amino alcohols and diastereomers possessing more than one stereocenter. The approach was utilized to monitor stereoselective biocatalytic transamination and assign the absolute configuration of the enantiomeric products. Finally, hydrolysis of the imine bond of the derivative was shown to generate enantiopure amine starting materials without racemization. This further highlights the value of this approach for creating readily reversed derivatives that enhance chromatographic separation and aid in the determination of absolute configuration.

The recently developed technology of droplet microfluidics has demonstrated great potential for many applications such as biochemical assay, high throughput screening, cell culture, directed evolution, and chemical synthesis. Intrigued by its capabilities for miniaturization, flexible manipulation, rapid reagent mixing and high throughput experimentation and analysis, the pharmaceutical industry has begun to investigate droplet microfluidic implementation in medicinal and process chemistry. Segmented by an immiscible secondary phase, usually perfluorinated oil, aqueous or organic droplets serve as individual micro-reactors without suffering cross-contamination. As many drug molecules contain fluorines, it is necessary to investigate whether such compounds will be preferentially extracted into the fluorous phase via fluorophilic solvation, which could lead to erroneous analytical results. In this work, we chose drugs with up to 10 fluorines to probe their partition into perfluorodecalin (PFD) from a variety of organic solvents. A fast and straightforward MISER (Multiple Injections in a Single Experimental Run) LC-MS method was applied to measure the loss of drug after mixing with PFD. We found that no significant partition occurred, with the concentration of drugs in the 'experimental' group measured as ±10% of the 'control' group. The RSD% of multiple injections is <5%. The finding was further validated by the conventional LC-MS approach., (Copyright © 2016 Elsevier B.V. All rights reserved.)

MISER chromatographic analysis (Multiple Injections in a Single Experimental Run) using supercritical fluid chromatography (SFC) with pressurized carbon dioxide-based eluents is well suited to the high throughput analysis of enantiopurity. SFC is currently the preferred method for fast enantiopurity analysis, with analysis times of only a few seconds achievable in some cases. Injector programming using both the Agilent Infinity and Shimadzu Nexera UC instruments permitted MISER SFC experiments to be performed. Several case studies are presented, showcasing the power and versatility of the technique, with 'plate analysis times' (the time required for analysis of enantiopurity of 96 samples) of less than 33-34 min achievable in the best cases., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Supercritical fluid chromatography (SFC) has long been a preferred method for enantiopurity analysis in support of pharmaceutical discovery and development, but implementation of the technique in regulated GMP laboratories has been somewhat slow, owing to limitations in instrument sensitivity, reproducibility, accuracy and robustness. In recent years, commercialization of next generation analytical SFC instrumentation has addressed previous shortcomings, making the technique better suited for GMP analysis. In this study we investigate the use of modern SFC for enantiopurity analysis of several pharmaceutical intermediates and compare the results with the conventional HPLC approaches historically used for analysis in a GMP setting. The findings clearly illustrate that modern SFC now exhibits improved precision, reproducibility, accuracy and robustness; also providing superior resolution and peak capacity compared to HPLC. Based on these findings, the use of modern chiral SFC is recommended for GMP studies of stereochemistry in pharmaceutical development and manufacturing., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The separation of fluorinated active pharmaceutical ingredients (APIs) from their desfluoro analogs is a challenging analytical task due to their structural similarity. In this work, fluorine containing APIs and their corresponding desfluorinated impurities were separated on five new 2.7μm superficially porous particles (SPPs) functionalized with bonded chiral selectors. The unique shape selectivity of bonded macrocyclic glycopeptides and oligosaccharides was utilized to separate seven pairs of fluoro/desfluoro APIs resulting in some unprecedented selectivity values. For example, SPP bonded isopropyl cyclofructan 6 yielded a selectivity of 2.73 for voriconazole and desfluoro voriconazole. Further, the SPP based columns allowed for rapid separations ranging from 9 to 55s with very high efficiencies ranging from 45,000 to 70,000plates/m (at high flow rates) in both reversed phase and polar organic modes. Chromatographic separation and detection by HPLC-ESI-MS was demonstrated using ezetimibe and voriconazole and their desfluorinated impurities. Among the tested phases, SPP hydroxypropyl-β-cyclodextrin separated the most fluorinated and desfluorinated analogs with baseline resolution., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Late-stage C-H fluorination is an appealing reaction for medicinal chemistry. However, the application of this strategy to process research appears less attractive due to the formation and necessary purification of mixtures of organofluorines. Here we demonstrate that γ-fluoroleucine methyl ester, an intermediate critical to the large-scale synthesis of odanacatib, can be accessed directly from leucine methyl ester using a combination of the decatungstate photocatalyst and N-fluorobenzenesulfonimide in flow. This efficient C-H fluorination reaction compares favorably with several generations of classical γ-fluoroleucine process syntheses.

Chromatographic enantioseparations on the order of a few seconds can be achieved by supercritical fluid chromatography using short columns packed with chiral stationary phases. The evolution of 'world record' speeds for the chromatographic separation of enantiomers has steadily dropped from an industry standard of 20-40 min just two decades ago, to a current ability to perform many enantioseparations in well under a minute. Improvements in instrument and column technologies enabled this revolution, but the ability to predict optimal separation time from an initial method development screening assay using the t(min cc) predictor greatly simplifies the development and optimization of high-speed chiral chromatographic separations. In this study, we illustrate how the use of this simple tool in combination with the workhorse technique of supercritical fluid chromatography on customized short chiral columns (1-2 cm length) allows us to achieve ultrafast enantioseparations of pharmaceutically relevant compounds on the 5-20 s scale, bringing the technique of high-throughput enantiopurity analysis out of the specialist realm and into the laboratories of most researchers., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Evaluation of a several fluorine-containing stationary phases for the chromatographic separation of fluorine-containing pharmaceuticals from their corresponding desfluoro analogs revealed a number of perfluoroaryl and perfluoroalky stationary phases that afford good separations. These fluorous stationary phases exhibit greater retention for the fluorine-containing compounds relative to the H-containing analogs, consistent with a fluorophilic retention mechanism. While both perfluoroalkyl and perfluoroaryl stationary phases afford adequate resolution, the perfluoroaryl columns generally exhibit superior separation factor (α) and peak efficiency (N), resulting in faster baseline separations, with the Hypersil Gold PFP and Poroshell 120 PFP columns providing the best overall performance for the test group studied., (Copyright © 2014 Elsevier B.V. All rights reserved.)

At the forefront of new synthetic endeavors, such as drug discovery or natural product synthesis, large quantities of material are rarely available and timelines are tight. A miniaturized automation platform enabling high-throughput experimentation for synthetic route scouting to identify conditions for preparative reaction scale-up would be a transformative advance. Because automated, miniaturized chemistry is difficult to carry out in the presence of solids or volatile organic solvents, most of the synthetic "toolkit" cannot be readily miniaturized. Using palladium-catalyzed cross-coupling reactions as a test case, we developed automation-friendly reactions to run in dimethyl sulfoxide at room temperature. This advance enabled us to couple the robotics used in biotechnology with emerging mass spectrometry-based high-throughput analysis techniques. More than 1500 chemistry experiments were carried out in less than a day, using as little as 0.02 milligrams of material per reaction., (Copyright © 2015, American Association for the Advancement of Science.)

Fast chiral supercritical fluid chromatography (SFC) separations have become important due to the increasing use of high-throughput experimentation (HTE) in organic synthesis. These HTE experiments can generate hundreds of samples for chiral analysis that need to be assayed in a short time. In general, chiral SFC can provide much faster analysis times compared to liquid chromatography (LC). Additionally, columns packed with smaller particles can provide faster and more efficient separations. In this study, the effect of the particle size on the speed and resolution of chiral separations by SFC was evaluated. The performance of Chiralcel OD columns packed with either 5 or 3 μm particles were compared using van Deemter or other kinetic plots. The benefits of using smaller particle columns for chiral SFC analysis are illustrated., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Several offline and online 2D HPLC methods were investigated for the reversed phase resolution of a complex mixture of closely related warfarin and hydroxywarfarin isomers. By combining reversed phase achiral/chiral HPLC separation with UV-triggered fraction collection and subsequent chiral/achiral reversed phase HPLC analysis of collected fractions, complete resolution of all 12 components of the mixture was possible. In addition, a faster method was developed from online 2D HPLC analysis where multicomponent fractions from the first dimension are simultaneously chromatographed in the second dimension., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The term t(min cc) provides a ready estimate of the shortest time that can be obtained by "column cutting" for baseline resolution of two components showing excess chromatographic resolution. While actual column cutting is impractical, the t(min cc) value is shown to be closely related to the minimum separation time obtainable by adjusting other parameters such as flow rate, mobile phase composition, and temperature, affording scientists interested in the development of fast chromatographic separations a convenient tool for estimating the minimum separation time that can be obtained by modifying a given method development screening result. Furthermore, the relationship between t(min cc) and the minimum separation time obtainable by adjusting other parameters is shown to be dependent on the speed of the screening method, with aggressive screening gradients affording t(min cc) estimates that match the actual minimum separation time, and "lazy" screening gradients affording t(min cc) values that overestimate minimum separation time. Consequently, the analysis of the relationship between t(min cc) and actual minimum separation time may be a useful tool for determining the "fitness" of method development screening methods., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Commercially available ultra high pressure liquid chromatography (UHPLC) equipment offers the ability to explore the influence of backpressure on chromatographic separations. However, the influence of pressure on the chromatographic separation of enantiomers on chiral stationary phases remains largely unexplored. In this investigation we surveyed the effects of pressure on the separation of enantiomers using several reversed-phase chiral stationary phases. The experiments were conducted at constant flow rate and column temperature, using isocratic conditions. The only variable parameter was pressure, which was adjusted using a post-column backpressure regulator. For the separation of enantiomers on chiral stationary phases, an increase in pressure from approximately 2,000 psi (138 bar) to approximately 8,000 psi (552 bar) at constant flow rate and temperature led to an increase of retention factors for some analytes and a decrease for others. Achiral separations on a C-18 stationary phase always led only to an increase of retention factor. Interestingly, changes in pressure led to small changes in enantioselectivity during reversed-phase chiral separation of enantiomers, suggesting that such studies may be of value for better understanding the mechanisms underlying chromatographic enantioseparation., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this study, we investigate the separation of a variety of mixtures of drugs, metabolites, and related analogs including representatives of the carbamazepine, methylated xanthine, steroid hormone, nicotine, and morphine families using several automated chromatographic method development screening systems including ultra high performance liquid chromatography, core-shell HPLC, achiral supercritical fluid chromatography (SFC), and chiral SFC. Of the 138 column and mobile phase combinations examined for each mixture, a few chromatographic conditions afford the best overall performance, with a single achiral SFC method (4.6 × 250 mm, 3.0 μm GreenSep Ethyl Pyridine, 25 mM isobutylamine in methanol/CO2) affording good separation for all samples. Four of these mixtures were also resolved by achiral SFC on the Luna HILIC and chiral SFC Chiralpak IB columns using methanol or ethanol with 25 mM isobutylamine as polar modifiers. Modifications of standard chromatography screening conditions afforded fast separation methods (from 1 to 5 min) for baseline resolution of all components of each of these challenging sets of closely related compounds., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The use of state-of-the-art separation tools from the pharmaceutical industry for addressing intractable separation problems from academic synthetic chemistry is evaluated, showing fast and useful results for the resolution of complex mixtures, separation of closely related components, visualization of difficult to detect compounds and purification of synthetic intermediates. Some recommendations for potential near term deployment of separation tools within academia and the evolution of next generation separation technologies are discussed.

The presence of dehalogenated impurities is often observed in halogen-containing pharmaceuticals, and can present a difficult analytical challenge, as the chromatographic behavior of the halogenated drug and the hydrogen-containing analog can be quite similar. In this study we describe the chromatographic separation and unambiguous identification of dehalogenation impurities or associated isomers in organohalogenated pharmaceuticals using UHPLC with a pentafluorophenyl column coupled with diode-array and high resolution electrospray ionization mass spectrometry detection (UHPLC-DAD-HRESIMS)., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The absolute configuration of several hydroxywarfarin isomers was assigned using a comparison of elution order on chiral stationary phases, optical rotation, and circular dichroism (CD) spectra, with confirmation of assignments made by comparison between experimental and calculated CD spectra and selective synthesis of hydroxywarfarin isomers from enantiopure warfarin using human liver microsomes., (Copyright © 2013 Wiley Periodicals, Inc.)

In recent years, the use of halogen-containing molecules has proliferated in the pharmaceutical industry, where the incorporation of halogens, especially fluorine, has become vitally important for blocking metabolism and enhancing the biological activity of pharmaceuticals. The chromatographic separation of halogen-containing pharmaceuticals from associated isomers or dehalogenation impurities can sometimes be quite difficult. In an attempt to identify the best current tools available for addressing this important problem, a survey of the suitability of four chromatographic method development platforms (ultra high-performance liquid chromatography (UHPLC), core shell HPLC, achiral supercritical fluid chromatography (SFC) and chiral SFC) for separating closely related mixtures of halogen-containing pharmaceuticals and their dehalogenated isosteres is described. Of the 132 column and mobile phase combinations examined for each mixture, a small subset of conditions were found to afford the best overall performance, with a single UHPLC method (2.1 × 50 mm, 1.9 μm Hypersil Gold PFP, acetonitrile/methanol based aqueous eluents containing either phosphoric or perchloric acid with 150 mM sodium perchlorate) affording excellent separation for all samples. Similarly, a survey of several families of closely related halogen-containing small molecules representing the diversity of impurities that can sometimes be found in purchased starting materials for synthesis revealed chiral SFC (Chiralcel OJ-3 and Chiralpak IB, isopropanol or ethanol with 25 mM isobutylamine/carbon dioxide) as well as the UHPLC (2.1 × 50 mm, 1.8 μm ZORBAX RRHD Eclipse Plus C18 and the Gold PFP, acetonitrile/methanol based aqueous eluents containing phosphoric acid) as preferred methods.

Aqueous and organic fractions from the crude extracts of 17 sponge species collected at Boca de Calderas, Havana, Cuba were analysed. The organic fractions of Mycale laxissima, Clathria echinata and Agelas cerebrum exhibited values of concentrations causing 50% inhibition of in vitro growth of Plasmodium berghei (IC50) of 42.3 ± 5.1, 52 ± 9.7 and 60.3 ± 10.6 μg/mL, respectively, while their selectivity indexes for fibroblast cell lines were 9.45, 4.24 and 8.7, correspondingly. These fractions reduced parasitemia of infected Balb/c mice as well. Selective cytotoxicity indexes against tumour HeLa cells focused an interest on the aqueous fraction of M. laxissima (>7.12) and organic fractions of Polymastia nigra (5.95), A. cerebrum (5.48) and Niphates erecta (>4.2). Triterpenoids/steroids and alkaloids detected in the organic fractions of M. laxissima, C. echinata and A. cerebrum should be isolated for future investigation.

Recent developments in the field of organic synthesis are leading to increasingly complex mixtures of closely related species (positional isomers, regioisomers, diastereomers, etc.) that often prove challenging for chromatographic analysis and separation. In this study we investigate the separation of a representative mixture of warfarin and 5 different monohydroxylation isomers to assess whether conventional techniques are suitable for addressing this separation challenge, or whether 'next generation' separation tools such as multidimensional chromatography may be required. In this example, modifications of results obtained from conventional achiral and chiral chromatography method development screening platforms afford rapid separation of all components for both achiral and chiral analysis, with supercritical fluid chromatography showing the best performance in both cases (1.8min for separation of six components by achiral SFC and 8.0min for separation of twelve components by chiral SFC). While other more complex mixtures may require additional tools, these results suggest that new applications of existing separation platforms may be useful for creating the chromatographic methods required to support this new area of synthetic chemistry., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this study we describe the evaluation of a recently developed supercritical fluid chromatography (SFC) instrument for automated chiral SFC method development. The greatly improved gradient dwell volume and liquid flow control of the new instrument in combination with the use of shorter columns containing smaller stationary phase particles affords chiral SFC method development that is faster and more universal than previous systems., (© 2013 Wiley Periodicals, Inc.)

In this study we investigate the recently reported use of water-containing modifiers for separation and purification of hydrophilic compounds by supercritical fluid chromatography. Improved peak shape is obtained for a variety of glycosides and otherwise hydrophilic compounds when 5% water is added to the methanol co-solvent used in SFC separations, and examples of the use of this approach in preparative SFC purifications are presented.

The aqueous ethanol extract of Thalassia testudinum leaves (BM-21) is now being developed in Cuba as an herbal medicine due to its promising pharmacological properties. Although some interesting biological activities of BM-21 have already been reported, its chemical composition remains mostly unknown. Thus, we now describe the qualitative and quantitative analyzes of BM-21 using standard phytochemical screening techniques, including colorimetric quantification, TLC and HPLC analyses. Phytochemical investigation of BM-21 resulted in the isolation and identification of a new phenolic sulfate ester (1), along with ten previously described phenolic derivatives (2-11), seven of which have never been previously reported from the genus Thalassia. The structures of these compounds were established by analysis of their spectroscopic (1D and 2D NMR) and spectrometric (HRMS) data, as well as by comparison of these with those reported in the literature. Furthermore, BM-21 was found to exhibit strong antioxidant activity in four different free radical scavenging assays (HO*, RO2*, O2-* and DPPH*). Consequently, this is the first study which highlights the phytochemical composition of BM-21 and demonstrates that this product is a rich source of natural antioxidants with potential applications in pharmaceutical, cosmetic and food industries.

The chemical composition of the aerial parts of the Cape Verdean endemic shrub Artemisia gorgonum Webb (Asteraceae) was careful investigated, which led to the isolation and identification of six known furfuran lignans: eudesmin (1), magnolin (2), epimagnolin A (3), aschantin (4), kobusin (5), sesamin (6) and a flavone: artemetin (7). Compounds 1-7 were evaluated in vitro for their cytotoxicity in a screening panel consisting of various mammalian tumor cell lines, for their antimalarial activity against chloroquine-resistant Plasmodium falciparum (FcB1 strain) and for their cytotoxicity against murine normal cells (CFU-GM). While no promising cytotoxicity against human tumor cells were noticed, marginal potency and selectivity was found for compounds 1-5 against murine colon 38. Besides, compounds 2-7 showed mild antiplasmodial activities, 6 and 7 being the most active compounds (IC(50) 3.37 and 3.50 μg/ml respectively) without noticeable toxicity on mammalian normal cells. This is the first report of antiplasmodial activity for furfuran lignans and the first isolation of 1-7 from Artemisia gorgonum., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Six new steroidal saponins, pandarosides K-M (1-3) and their methyl esters (4-6), were isolated as minor components, after a careful chemical reinvestigation of the Caribbean sponge Pandaros acanthifolium. Their structures were established on the basis of spectroscopic analyses and comparison with the data obtained from previous metabolites of this family. All new compounds showed moderate to weak activity against four parasitic protozoa. Additionally, these compounds and previously reported pandarosides and acanthifoliosides were tested on three human tumour cell lines, and their haemolytic and liposome permeabilizing activity were assessed. Two pandarosides exhibited moderate to strong cytotoxic effect, while three acanthifoliosides showed strong haemolytic activity., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Beverages, especially wines are well-known to contain a variety of health-beneficial bioactive substances, mainly of phenolic nature which frequently exhibit antioxidant activity. Significant information is available about the separation and identification of polyphenols from some beverages by chromatographic and spectroscopic techniques, but considerably poor is chemical data related to the polyphenolic content in rums. In this paper, a method involving the all-liquid chromatographic technique of high-speed countercurrent chromatography (HSCCC) combined with high-performance liquid chromatography coupled with diode-array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS(n)) has been successfully applied for separation and identification of phenolic compounds in an aged rum. Besides, the phenolic fraction (PF) was assayed for its antioxidant effects using three different free radical in vitro assays (DPPH·, RO(2)· and spontaneous lipid peroxidation (LPO) on brain homogenates) and on ferric reducing antioxidant power (FRAP). Results showed that PF potently scavenged DPPH and strongly scavenged peroxyl radicals compared to ascorbic acid and butylated hydroxytoluene (BHT); and almost equally inhibited LPO on brain homogenates subjected to spontaneous LPO when compared to quercetin. Moreover, PF also exhibited strong reducing power. This chemical analysis illustrates the rich array of phenols in the aged rum and represents a rapid and suitable method for the isolation and identification of phenolic compounds from mixtures of considerable complexity, achieving high purity and reproducibility with the use of two separation steps., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The apolar fraction F1 of Thalassia testudinum was chemically characterized by gas chromatography-mass spectrometry, which led to the identification of 43 metabolites, all of them reported for the first time in the genus Thalassia. More than 80% of the F1 composition was constituted by aromatic metabolites including the major components 1,1-bis(p-tolyl)ethane (6.0%), 4,4'-diisopropylbiphenyl (4.8%) and a 1,1-bis(p-tolyl)ethane isomer (4.7%). This lipophilic fraction was assayed for its antioxidant effects and skin protective action. In vitro assays showed that F1 strongly scavenged DPPH* (IC(50) 312.0 ± 8.0 μg mL(-1)), hydroxyl (IC(50) 23.8 ± 0.5 μg mL(-1)) and peroxyl radical (IC(50) 6.6 ± 0.3 μg mL(-1) ), as well as superoxide anion (IC(50) 50.0 ± 0.7 μg mL(-1)). Also, F1 markedly inhibited the spontaneous lipid peroxidation (LPO) in brain homogenates (IC(50) 93.0 ± 6.0 μg mL(-1)) and the LPS-stimulated nitrite generation on RAW624.7 macrophages (58.6 ± 3.2%, 400 μg mL(-1)). In agreement with these findings, its topical application at 250 and 500 μg cm(-2) strikingly reduced skin damage on mice exposed to acute UVB radiation by 45% and 70%, respectively and significantly attenuated the LPO developed following the first 48 h after acute exposure to UVB irradiation, as manifested by the decreased malondialdehide level and by the increased of reduced gluthatione content. Our results suggest that F1 may contribute to skin repair by attenuating oxidative stress due to its antioxidant activity., (© 2011 The Authors. Photochemistry and Photobiology © 2011 The American Society of Photobiology.)

The chemical composition of Tornabenea bischoffii J. A. Schmidt essential oil from Cape Verde was studied by GC and GC/MS. Sixty volatile compounds were identified of which myristicin was the major constituent (33.6%). Using the 2,2-diphenyl-2-picrylhydrazyl free-radical scavenging method and the in vitro assay for prevention of lipid peroxidation by thiobarbituric reactive species, significant antioxidant activities were evidenced.

Background: Acid-sensing ion channels (ASICs) have a significant role in the sensation of pain and constitute an important target for the search of new antinociceptive drugs. In this work we studied the antinociceptive properties of the BM-21 extract, obtained from the sea grass Thalassia testudinum, in chemical and thermal models of nociception in mice. The action of the BM-21 extract and the major phenolic component isolated from this extract, a sulphated flavone glycoside named thalassiolin B, was studied in the chemical nociception test and in the ASIC currents of the dorsal root ganglion (DRG) neurons obtained from Wistar rats., Results: Behavioral antinociceptive experiments were made on male OF-1 mice. Single oral administration of BM-21 produced a significant inhibition of chemical nociception caused by acetic acid and formalin (specifically during its second phase), and increased the reaction time in the hot plate test. Thalassiolin B reduced the licking behavior during both the phasic and tonic phases in the formalin test. It was also found that BM-21 and thalassiolin B selectively inhibited the fast desensitizing (τ < 400 ms) ASIC currents in DRG neurons obtained from Wistar rats, with a nonsignificant action on ASIC currents with a slow desensitizing time-course. The action of thalassiolin B shows no pH or voltage dependence nor is it modified by steady-state ASIC desensitization or voltage. The high concentration of thalassiolin B in the extract may account for the antinociceptive action of BM-21., Conclusions: To our knowledge, this is the first report of an ASIC-current inhibitor derived of a marine-plant extract, and in a phenolic compound. The antinociceptive effects of BM-21 and thalassiolin B may be partially because of this action on the ASICs. That the active components of the extract are able to cross the blood-brain barrier gives them an additional advantage for future uses as tools to study pain mechanisms with a potential therapeutic application.

The phytochemical profile of Melaleuca leucadendra L. leaf and fruit oils from Cuba was investigated by GC and GC/MS. Forty-one and sixty-four volatile compounds were identified and quantified, accounting for 99.2 and 99.5% of the leaf-oil and fruit-oil total composition, respectively. The main components were 1,8-cineol (43.0%), viridiflorol (24.2%), α-terpineol (7.0%), α-pinene (5.3%), and limonene (4.8%) in the leaf oil, and viridiflorol (47.6%), globulol (5.8%), guaiol (5.3%), and α-pinene (4.5%) in the fruit oil. The antioxidant capacity of these essential oils was determined by three different in vitro assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, thiobarbituric acid reactive species (TBARS), and 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation), and significant activities were evidenced for all of them.

The chemical composition of the Caribbean sponge Pandaros acanthifolium was reinvestigated and led to the isolation of 12 new steroidal glycosides, namely, pandarosides E-J (1-6) and their methyl esters (7-12). Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. Like the previously isolated pandarosides A-D (13-16), the new compounds 1-12 share an unusual oxidized D-ring and a cis C/D ring junction. The absolute configurations of the aglycones were assigned by interpretation of CD spectra, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid methanolysates. The majority of the metabolites showed in vitro activity against three or four parasitic protozoa. Particularly active were the compounds 3 (pandaroside G) and its methyl ester (9), which potently inhibited the growth of Trypanosoma brucei rhodesiense (IC(50) values 0.78 and 0.038 microM, respectively) and Leishmania donovani (IC(50)'s 1.3 and 0.051 microM, respectively).

A method involving flash chromatography, semi-preparative phenylhexyl RP HPLC-DAD-ELSD combined with analytic polar-RP HPLC-DAD, was applied to separate and purify six highly nitrogenated bases and a bicyclic amidine alkaloid, the major components of the marine sponge Niphates digitalis. Their structures were identified as 1,8-diazabicyclo[5.4.0]undec-7-ene (1), deoxycytidine (2), phenylalanine (3), adenosine (4), deoxyguanosine (5), adenine (6) and thymidine (7) on the basis of spectroscopic data analyses. This is the first report of these compounds in a marine sponge belonging to the Niphates genus and the first evidence of the presence of 1 from a natural source.

The chemical composition of Artemisia gorgonum Webb essential oil from Cape Verde was analyzed by GC and GC/MS. A total of 111 volatile compounds, accounting for 94.9% of the essential oil, were identified by GC and GC/MS. The major compounds were camphor (28.7%), chrysanthenone (10.8%), lavandulyl 2-methylbutanoate (9.5%), alpha-phellandrene (5.5%), lavandulyl propanoate (4.2%), camphene (4.0%), and p-cymene (3.4%). The volatile oil of this endemic plant, which is used in Cape Verdean folk medicine against several ailments, was tested for its antioxidant and antimalarial properties, and was found to exhibit free-radical scavenging on 1,1-diphenyl-2-picrylhydrazyl (DPPH), prevention of lipid peroxidation-in vitro by TBARS (thiobarbituric acid reactive species) assay, and antiplasmodial activity.

The chemical composition of the Caribbean sponge Pandaros acanthifolium was investigated and led to the isolation of seven new steroidal glycosides namely pandarosides A-D (1, 3, 4 and 6) along with the three methyl esters of pandarosides A, C, and D (2, 5 and 7). Their structures were characterized as 3beta-[beta-glucopyranosyl-(1-->2)-beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-poriferast-16-ene-15,23-dione (1) and its methyl ester (2), 3beta-[beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-poriferast-16-ene-15,23-dione (3), 3beta-[beta-glucopyranosyl-(1-->2)-beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-cholest-16-ene-15,23-dione (4) and its methyl ester (5), 3beta-(beta-glucopyranosyloxyuronic acid)-16-hydroxy-5alpha,14beta-cholest-16-ene-15,23-dione (6) and its methyl ester (7) on the basis of detailed spectroscopic analyses, including 2D NMR and HRESIMS studies. Pandarosides A-D and their methyl esters (1-7) are all characterized by a rare 2-hydroxycyclopentenone D-ring with a 14beta configuration. The absolute configuration of the aglycon part of pandaroside A (1) was assigned by comparison between experimental and TDDFT calculated circular dichroism spectra on the more stable conformer.

The chemical composition of essential oil from the air-dried aerial parts of Satureja forbesii (Benth.) Briq. from Cape Verde was studied by GC and GC/MS. Thirty-nine volatile compounds were identified of which geranial (42.0%) and neral (31.2%) were the major constituents. Using the 2,2-diphenyl-2-picrylhydrazyl free-radical scavenging method and the in vitro assay for prevention of lipid peroxidation by thiobarbituric reactive species, significant activities were evidenced.

Five new hydantoin alkaloids, named parazoanthines A-E (1-5), were isolated as the major constituents of the Mediterranean sea anemone Parazoanthus axinellae. Their structural elucidation was achieved through NMR spectroscopic and mass spectrometric analyses. The absolute configuration of the chiral compounds 1 and 4 was determined by comparison between experimental and TDDFT-calculated CD spectra. The configuration of the trisubstituted double bond of 2, 3, and 5 was deduced from the (3)J(H6-C4) coupling constant value. This family of alkaloids represents the first example of natural 3,5-disubstituted hydantoins that do not exhibit a methyl at N-3. All compounds were tested for their natural toxicity (Microtox assay), and parazoanthine C (3) exhibited the highest natural toxicity.

Daily topical application of the aqueous ethanolic extract of the marine sea grass, Thalassia testudinum, on mice skin exposed to UVB radiation resulted in a dose-dependent recovery of the skin macroscopic alterations over a 6-day period. Maximal effect (90%) occurred at a dose of 240 microg/cm(2), with no additional effects at higher doses. Bioassay-guided fractionation of the plant extract resulted in the isolation of thalassiolin B (1). Topical application of 1 (240 microg/cm(2)) markedly reduces skin UVB-induced damage. In addition, thalassiolin B scavenged 2,2-diphenyl-2-picrylhydrazyl radical with an EC(50) = 100 microg/ml. These results suggest that thalassiolin B is responsible for the skin-regenerating effects of the crude extract of T. testudinum.