Conformationally Defined Rexinoids for the Prevention of Inflammation and Nonmelanoma Skin Cancers

Compound 1 is a potent rexinoid that is highly effective in cancer chemoprevention but elevates serum triglycerides. In an effort to separate the lipid toxicity from the anticancer activity of 1, we synthesized four new analogs of rexinoid 1, of which three rexinoids did not elevate serum triglycerides. Rexinoids 3 and 4 are twice as potent as rexinoid 1 in binding to Retinoid X receptor (RXR). All-trans retinoic acid (ATRA) plays a key role in maintaining skin homeostasis, and rexinoids 3-6 are highly effective in upregulating the genes responsible for the biosynthesis of ATRA. Inflammation plays a key role in skin cancer, and rexinoids 3 and 4 are highly effective in diminishing LPS-induced inflammation. Rexinoids 3 and 4 are highly effective in preventing UVB-induced nonmelanoma skin cancer (NMSC) without displaying any overt toxicities. Biophysical studies of rexinoids 3 and 5 bound to hRXRα-ligand binding domain (LBD) reveal important conformational and dynamical differences in the ligand binding domain.

Antinociceptive effects of rotigotine-loaded microspheres and its synergistic interactions with analgesics in inflammatory pain in rats

Rotigotine-loaded microspheres (RoMS) are sustained-release formulations with prolonged anti-Parkinson's effects. Given that pain is a non-motor symptom of Parkinson's disease, this study investigated the antinociceptive effects of RoMS and their synergistic effects with analgesics on inflammatory pain. A model of inflammatory pain was prepared by intraplantarly injecting male Sprague-Dawley rats with carrageenan. The antinociceptive effects of RoMS, acetaminophen, and tramadol, both alone and in combination, were evaluated using the hind paw withdrawal latency in the hot plate test and Randall-Selitto test. The rotigotine concentrations in serum and tissues were assayed using ultra-performance liquid chromatography-tandem mass spectrometry. Isobolographic analysis was performed to evaluate the nature of the interactions of RoMS with acetaminophen or tramadol. The results showed that hind paw withdrawal latency to thermal and mechanical stimuli was significantly increased on day 3 and 7 after administered RoMS. Rotigotine could be detected in serum and tissues 3 and 7 days after an intramuscular injection of RoMS. However, the rotigotine concentration fell the detection limit of the assay on day 14 after administration. RoMS produced synergistic antinociceptive effects in the inflammatory pain model when RoMS is combined with acetaminophen or tramadol. These findings suggest that RoMS can relieve inflammatory pain in rats. Furthermore, the combination of RoMS with acetaminophen or tramadol produces synergistic antinociception, which may be clinically worthy because combination therapies may reduce the drug doses required for antinociception.

The novel rexinoid MSU-42011 is effective for the treatment of preclinical Kras-driven lung cancer

Effective drugs are needed for lung cancer, as this disease remains the leading cause of cancer-related deaths. Rexinoids are promising drug candidates for cancer therapy because of their ability to modulate genes involved in inflammation, cell proliferation or differentiation, and apoptosis through activation of the retinoid X receptor (RXR). The only currently FDA-approved rexinoid, bexarotene, is ineffective as a single agent for treating epithelial cancers and induces hypertriglyceridemia. Here, we used a previously validated screening paradigm to evaluate 23 novel rexinoids for biomarkers related to efficacy and safety. These biomarkers include suppression of inducible nitric oxide synthase (iNOS) and induction of sterol regulatory element-binding protein (SREBP). Because of its potent iNOS suppression, low SREBP induction, and activation of RXR, MSU-42011 was selected as our lead compound. We next used MSU-42011 to treat established tumors in a clinically relevant Kras-driven mouse model of lung cancer. KRAS is one of the most common driver mutations in human lung cancer and correlates with aggressive disease progression and poor patient prognosis. Ultrasound imaging was used to detect and monitor tumor development and growth over time in the lungs of the A/J mice. MSU-42011 markedly decreased the tumor number, size, and histopathology of lung tumors compared to the control and bexarotene groups. Histological sections of lung tumors in mice treated with MSU-42011 exhibited reduced cell density and fewer actively proliferating cells compared to the control and bexarotene-treated tumors. Although bexarotene significantly (p < 0.01) elevated plasma triglycerides and cholesterol, treatment with MSU-42011 did not increase these biomarkers, demonstrating a more favorable toxicity profile in vivo. The combination of MSU-42011 and carboplatin and paclitaxel reduced macrophages in the lung and increased activation markers of CD8+T cells compared to the control groups. Our results validate our screening paradigm for in vitro testing of novel rexinoids and demonstrate the potential for MSU-42011 to be developed for the treatment of KRAS-driven lung cancer.

Sorption of Tonalide, Musk Xylene, Galaxolide, and Musk Ketone by microplastics of polyethylene and polyvinyl chloride

The effects of time, temperature, and salinity on the adsorption of Tonalide (AHTN), Musk Xylene (MX), Galaxolide (HHCB), and Musk Ketone (MK) by microplastics of polyethylene (PE) and polyvinyl chloride (PVC) are studied. Results indicate that the equilibrium sorption time was about 10 h and the adsorption kinetics model conformed to the first-order adsorption kinetic model and pseudo-second order kinetic model, this indicates that the main adsorption mechanism might be chemical adsorption and physical absorption. Adsorption reached a nadir at 15 °C and 14% salinity. The adsorption capacity gradually increases, and then decreases, finally increases with an increase in NaCl concentration. Due to the specific surface area and the pore volume of PVC was larger than PE, the adsorption capacity of PVC was higher than that of PE in the equal conditions.

Compatibility and stability of dezocine and tropisetron in 0.9% sodium chloride injection for patient-controlled analgesia administration

Tropisetron is an adjuvant for dezocine used in intravenous patient-controlled analgesia (PCA) and has been reported to provide superior pain control. It is efficacious in reducing the institutional incidence of postoperative nausea and vomiting (PONV), which decreases resource utilization and cost. However, no scientific evidence has been reported in the literature demonstrating analytical confirmation of the compatibility and stability of the combination of dezocine and tropisetron. Thus, the present study aimed to investigate the stability of dezocine with tropisetron in 0.9% sodium chloride injection form for PCA administration.Commercial solutions of dezocine and tropisetron were combined and examined for compatibility and stability when diluted with 0.9% sodium chloride injection in polyolefin bags and glass bottles stored at 4°C or 25°C for up to 14 days. The initial concentrations were 40 mg/100 mL dezocine and 5 mg/100 mL tropisetron. For all samples, the compatibility parameters (including precipitation, cloudiness, discoloration, and pH values) were evaluated. Chemical stability was also determined using high-performance liquid chromatographic (HPLC) analysis.After a 14-day period of storage at 4°C or 25°C, the initial concentrations of dezocine and tropisetron were maintained at at least 98%. All of the mixtures remained clear and colorless throughout the observation period, and no color change or precipitation was observed.These results indicated that admixtures of 40 mg/100 mL dezocine and 5 mg/100 mL tropisetron in 0.9% sodium chloride injection were stable for at least 14 days when stored in polyolefin bags or glass bottles at 4°C or 25°C and protected from light.

Radiosynthesis and evaluation of a fluorine-18 labeled radioligand targeting vesicular acetylcholine transporter

Vesicular acetylcholine transporter (VAChT) is a reliable biomarker for assessing the loss of cholinergic neurons in the brain that is associated with cognitive impairment of patients. 5-Hydrotetralin compound (±)-5-OH-VAT is potent (K_i = 4.64 ± 0.32 nM) and selective for VAChT (>1800-fold and 398-fold for σ₁ and σ₂ receptor, respectively) with favorable hydrophilicity (LogD = 1.78), while (-)-5-OH-VAT originally serves as the radiolabeling precursor of (-)-[¹⁸F]VAT, a promising VAChT radiotracer with a logD value of 2.56. To evaluate (-)-5-OH-[¹⁸F]VAT as a radiotracer for VAChT, we performed in vitro binding assay to determine the potency of the minus enantiomer (-)-5-OH-VAT and plus enantiomer (+)-5-OH-VAT, indicating that (-)-5-OH-VAT is a more potent VAChT enantiomer. Radiosynthesis of (-)-5-OH-[¹⁸F]VAT was explored using three strategies. (-)-5-OH-[¹⁸F]VAT was achieved with a good yield (24 ± 6%) and high molar activity (∼37 GBq/µmol, at the end of synthesis) using a microwave assisted two-step one-pot procedure that started with di-MOM protected nitro-containing precursor (-)-6. MicroPET studies in the brain of nonhuman primate (NHP) suggest that (-)-5-OH-[¹⁸F]VAT readily penetrated the blood brain barrier and specifically accumulated in the VAChT-enriched striatum with improved washout kinetics from striatum compared to [¹⁸F]VAT. Nevertheless, the lower target to non-target ratio may limit its use for in vivo measurement of the VAChT level in the brain.

Effect of antioxidant compounds from seaweeds on storage stability of C20-22 polyunsaturated fatty acid concentrate prepared from dogfish liver oil

Ethyl acetate extracts of seaweeds were chromatographically fractionated to yield 14-methyl pentyl tetrahydro-8-hydroxy-10-methylnaphthalene-8-carboxylate (1) and tetrahydro-4-isopropyl-9-(9, 14-dimethyldec-9-enyl)-pyran-1-one (2) from Sargassum ilicifolium, whereas Padina gymnospora afforded dihydro-2-(10-(hydroxymethyl)-7,15-dimethyl-9-oxoundec-11-enyl)-2-methyl-2H-pyran-1(4H)-one (3) and 1-(decahydro-1-hydroxy-7-methyl-8-vinylnaphthalen-2-yl)ethanone (4) as major constituents. Compound 1 displayed significantly higher antioxidant activity (IC50 < 1 mg/mL, p < 0.05) comparable to other analogues (IC50 > 1 mg/mL). The C20-22 polyunsaturated fatty acid (C20-22 PUFA) concentrate (CFA) prepared from the deep-sea dogfish liver oil was added with the studied compounds and physiochemical properties and fatty acid composition during an accelerated storage were evaluated. No significant reduction in C20-22 PUFAs (∼6%) in the CFA treated with 1 as compared to that with the control (∼35%) was recorded. A greater induction time was observed for the CFA supplemented with 1 (6.8 h) than other compounds (≤6 h) and control (∼1.6 h), maintaining the oxidation indices of the CFA within desirable limits.

Design and synthesis of a potent, highly selective, orally bioavailable, retinoic acid receptor alpha agonist

A ligand-based virtual screening exercise examining likely bioactive conformations of AM 580 (2) and AGN 193836 (3) was used to identify the novel, less lipophilic RARα agonist 4-(3,5-dichloro-4-ethoxybenzamido)benzoic acid 5, which has good selectivity over the RARβ, and RARγ receptors. Analysis of the medicinal chemistry parameters of the 3,5-substituents of derivatives of template 5 enabled us to design a class of drug-like molecules with lower intrinsic clearance and higher oral bioavailability which led to the novel RARα agonist 4-(3-chloro-4-ethoxy-5-isopropoxybenzamido)-2-methylbenzoic acid 56 that has high RARα potency and excellent selectivity versus RARβ (2 orders of magnitude) and RARγ (4 orders of magnitude) at both the human and mouse RAR receptors with improved drug-like properties. This RARα specific agonist 56 has high oral bioavailability (>80%) in both mice and dogs with a good PK profile and was shown to be inactive in cytotoxicity and genotoxicity screens.

Stereoselective Dynamic Cyclization of Allylic Azides: Synthesis of Tetralins, Chromanes, and Tetrahydroquinolines

This report describes the stereoselective synthesis of 3-azido-tetralins, -chromanes, and -tetrahydroquinolines via a tandem allylic azide rearrangement/Friedel-Crafts alkylation. Exposure of allylic azides with a pendant trichloroacetimidate to catalytic quantities of AgSbF6 proved optimal for this transformation. This cascade successfully differentiates the equilibrating azide isomers, providing products in excellent yield and selectivity (>25 examples, up to 94% yield and >25:1 dr). In many cases, the reactive isomer is only a trace fraction of the equilibrium mixture, keenly illustrating the dynamic nature of these systems. We demonstrate the utility of this process via a synthesis of hasubanan.

Sorption of three synthetic musks by microplastics

Microplastics and synthetic musks (SMs) are two typical organic pollutants in the marine environment. In this study, the sorption of three SMs to microplastics in a simulated seawater environment was examined. Tonalide (AHTN), musk xylene (MX), and musk ketone (MK) were the musks investigated, while polypropylene (PP) was used as the microplastic. It was found that the equilibrium sorption time was about 10h and the adsorption kinetics model conformed to a Lagergren adsorption model. The adsorption capacity increased with decreasing particle size. Adsorption reached a peak at 25°C, and the adsorption capacity was not sensitive to the concentration of sodium chloride. There is a need for more research and monitoring of microplastics in the marine environment due to their strong ability to absorb organic pollutants.

Stability study of dezocine in 0.9% sodium chloride solutions for patient-controlled analgesia administration

BACKGROUND

Dezocine, a mixed agonist/antagonist of opioid receptors, has been used in iv patient-controlled analgesia (PCA) pumps for postoperative pain control. The aim of this study was to investigate the physicochemical stability of dezocine solutions in 0.9% sodium chloride for injection for PCA administration.

METHODS

Solutions of dezocine (0.3, 0.45, or 0.6 mg/mL in 0.9% sodium chloride for injection) were stored in polyolefin bags and glass bottles. Their stabilities at storage conditions of 4°C for 14 days and 25°C for 72 hours were studied. For all preparations, physical characteristics (including pH, color, and presence of precipitates) were evaluated. Each preparation of dezocine was also analyzed using a stability-indicating high-performance liquid chromatography method. A solution was considered stable if it maintained at least 90% of its initial concentration.

RESULTS

No notable changes in pH, color, or precipitation were observed in any of the prepared solutions over the testing period. All formulations maintained >97% of the initial dezocine concentration under the storage conditions evaluated.

CONCLUSIONS

Dezocine solutions at 0.3, 0.45, or 0.6 mg/mL in 0.9% sodium chloride for PCA administration were stable for 72 hours at 25°C and for 14 days at 4°C when packaged in polyolefin bags or glass bottles and protected from light.

Derivatives of the Lignan 7'-Hydroxymatairesinol with Antioxidant Properties and Enhanced Lipophilicity

The lignan 7'-hydroxymatairesinol (1), extracted from the knotwoods of fir (Abies alba), spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii), exhibited unexpected reactivity when esterification reactions were attempted on the hydroxy group at position C-7'. To circumvent the rapid intramolecular cyclization procedure, leading quantitatively to the lignan conidendrin (7), a simple strategy for 7'-esterification of 1 under mild conditions (three steps, up to 80% overall yield) was developed. Compared to hydroxymatairesinol (1) (log K'_w = 1.49), the derivatives (2-5) had increased lipophilicity with log K'_w > 3.1, as determined by a UHPLC method. Compounds 1-5 exhibited potent antioxidant properties in the same range as the standards ascorbic acid and α-tocopherol (IC₅₀ = 20-25 μM) and higher than that of BHT using a DPPH radical-scavenging assay.

Molecular dynamics simulations and molecular flooding studies of the retinoid X-receptor ligand binding domain

Bexarotene is an FDA approved retinoid X-receptor (RXR) agonist for the treatment of cutaneous T-cell lymphoma, and its use in other cancers and Alzheimer's disease is being investigated. The drug causes serious side effects, which might be reduced by chemical modifications of the molecule. To rationalize known agonists and to help identify sites for potential substitutions we present molecular simulations in which the RXR ligand-binding domain was flooded with a large number of drug-like molecules, and molecular dynamics simulations of a series of bexarotene-like ligands bound to the RXR ligand-binding domain. Based on the flooding simulations, two regions of interest for ligand modifications were identified: a hydrophobic area near the bridgehead and another near the fused ring. In addition, positional fluctuations of the phenyl ring were generally smaller than fluctuations of the fused ring of the ligands. Together, these observations suggest that the fused ring might be a good target for the design of higher affinity bexarotene-like ligands, while the phenyl ring is already optimized. In addition, notable differences in ligand position and interactions between the RXRα and RXRβ were observed, as well as differences in hydrogen bonding and solvation, which might be exploited in the development of subspecies-specific ligands.

Insights into the structure-activity relationship of the anticancer compound ZJ-101, a derivative of marine natural product superstolide A: A critical role played by the conjugated trienyl lactone moiety

Compound ZJ-101, a structurally simplified analog of the marine natural product superstolide A, was previously developed in our laboratory. In the subsequent structure-activity relationship study, two new analogs, ZJ-105 and ZJ-106, were designed and synthesized to probe the importance of the conjugated trienyl lactone moiety of the molecule by replacing the C2-C3 double bond in ZJ-101 with a single bond and switching the geometry of the C4-C5 double bond in ZJ-101 from Z to E, respectively. Biological evaluation showed that ZJ-105 completely loses antiproliferative activity whereas ZJ-106 is significantly less active against cancer cells in vitro than ZJ-101, suggesting that the conjugated trienyl lactone moiety of the molecule is critical for its anticancer activity.

RIFM fragrance ingredient safety assessment, 1-(1,2,3,4-tetrahydro-4,4-dimethyl-1-naphthyl)propan-1-one, CAS Registry Number 74499-60-8

The use of this material under current use conditions is supported by the existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the target material and the suitable read across analog 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (CAS # 21145-77-7) show that this material is not genotoxic. Data from the suitable read across analog 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (CAS # 21145-77-7) provided a MOE > 100 for the repeat dose and developmental toxicity endpoints. The reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class II material (0.009 mg/kg/day and 0.47 mg/day, respectively). Data on the target material showed that this material is below the non-reactive DST for skin sensitization and did not have the potential for phototoxicity or photoallergenicity. The environmental endpoint was completed as described in the RIFM Framework.

Removal of polycyclic synthetic musks and antineoplastic drugs in ozonated wastewater: Quantitation based on the data of differential spectroscopy

This study examined the degradation behavior of polycyclic musks (PMs) and antineoplastic drugs (ADs) and the absorbance spectra of effluent organic matter (EfOM) in municipal wastewater by ozone. Specific ozone doses used in the experiments ranged from 0 to 1mg O3/mg dissolved organic matter (DOC). The examined PMs included galaxolide, tonalide, celestolide, traseolide and phantolide. ADs included busulfan, chlorambucil, cyclophosphamide, dacarbazine, flutamide, ifosfamide, tamoxifen and methotrexate. Strong monotonic albeit nonlinear correlations were found to exist between relative changes of EfOM absorbance at 254 nm (i.e. ΔA254/A(0)254) and the degradation of the selected PMs and ADs. This result was interpreted based on the concept of the simultaneous oxidation of EfOM and, on the other hand, PMs and ADs. This interpretation showed that PMs were degraded primarily via OH radical attack, with tonalide and phantolide being less reactive compared with the other PMs. ADs such as cyclophosphamide, ifosfamide and busulfan were also determined to undergo oxidation by OH radicals. Comparison of the behavior of the radical probe para-chlorobenzoic acid and the examined ADs and PMs allowed evaluating corresponding reaction rate constants for reactions between these species and OH radicals.

Chemical Characterization and Botanical Origin of French Ambers

The molecular composition of 10 Cretaceous and one Eocene ambers from France was analyzed by infrared spectroscopy, solid-state (13)C nuclear magnetic resonance spectroscopy, and thermochemolysis gas chromatography-mass spectrometry. The terpenoids identified in the samples were used as biomarkers for the botanical origin of the resins. The Cretaceous samples, comprising the so-called Alpine, Anjou, Charentese, Provence, Pyrenean, and Vendean ambers, ranged from the Albian-Cenomanian transition to the early Santonian (100 to 85 Ma) and correspond to class Ib resins typical of conifers. The extinct conifer family Cheirolepidiaceae was proposed as the plant source of Pyrenean and brown Charentese ambers. Araucariaceae or Cheirolepidiaceae were the plant sources of the Cenomanian Alpine, Anjou, and yellow Charentese ambers. The Santonian ambers of Provence and Vendée were found to derive from the Cupressaceae. The Eocene Oise amber (ca. 53 Ma) is a class Ic resin typical of angiosperms and was produced by a Fabaceae. The evolution of resin sources from the early Cretaceous to the Eocene periods is discussed. Finally, a possible fingerprint hitherto unveiled is proposed for cheirolepidiaceous resins, defined by the simultaneous presence of phenolic diterpenoids, labdanoic acids, callitrisate structures, and their respective derivatives.

Effect of confertifolin from Polygonum hydropiper L. against dengue vector mosquitoes Aedes aegypti L

The essential oil from the leaves of Polygonum hydropiper L. (Polygonaceae) was tested against Aedes aegypti L. The LC50 values were 190.72 and 234.37 ppm against second and fourth instar larvae of A. aegypti, respectively. Confertifolin (6,6,9a-trimethy l-4,5,5a,6,7,8,9,9a-octahydronaphtho [1,2-c] furan-3 (1H)-one) was isolated from the essential oil of P. hydropiper leaves using silica gel column chromatography. The LC50 values were 2.90 and 2.96 ppm for second and fourth instar larvae of A. aegypti, respectively. At 10 ppm, the concentration of confertifolin showed ovicidal activity of 100, 100, and 77.6 % on 0-6, 6-12, and 12-18 h old eggs; the repellent activity was 323.2 min; and oviposition deterrent activity was 97.52 % and adulticidal activity was 100 % against A. aegypti. The results were statistically significant at P < 0.05 level. The results suggested that confertifolin as an effective major constituent against A. aegypti and might be considered as a potent source for the production of superior natural mosquitocides.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF CYANOPYRIDINYL TETRAHYDRONAPHTHALENE DERIVATIVES

A novel series of cyanopyridinyl tetrahydronaphthalene incorporated with different heterocycles were synthesized. The key compounds 2a,b were condensed with chloroacetone and ethyl chloroacetate to give 3a,b and 4a,b, respectively. Also condensation of 4a,b with hydrazine hydrate gave the corresponding hydrazide 5a,b. Reaction of 5b with different isothiocyanates gave the corresponding thiosemicarbazide derivatives 6a-c. Also, condensation of 5a with chloroacetic acid, methyl iodide and/or acetic anhydride yielded 7- 9, respectively. Moreover, reaction of 5a with acetylacetone, ethyl acetoacetate, diethylmalonate, ethyl cyanoacetate, chloroacetone, ethyl chloroacetate, urea, phthalic anhydride, malic anhydride and/ or different aldehydes yielded the corresponding derivatives 10-18, respectively. Newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium, Sarcina lutea, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli) and antifungal (Saccharomyces cerevisiae and Candida albicans) activity. The results revealed that some of novel compounds have exhibited significant biological activity against the tested microorganisms.

Stereochemical assignment of the protein-protein interaction inhibitor JBIR-22 by total synthesis

Recent reports have highlighted the biological activity associated with a subfamily of the tetramic acid class of natural products. Despite the fact that members of this subfamily act as protein-protein interaction inhibitors that are of relevance to proteasome assembly, no synthetic work has been reported. This may be due to the fact that this subfamily contains an unnatural 4,4-disubstitued glutamic acid, the synthesis of which provides a key challenge. A highly stereoselective route to a masked form of this unnatural amino acid now enabled the synthesis of two of the possible diastereomers of JBIR-22 and allowed the assignment of its relative and absolute stereochemistry.

Isolation of pyrrolocins A-C: cis- and trans-decalin tetramic acid antibiotics from an endophytic fungal-derived pathway

Three new decalin-type tetramic acid analogues, pyrrolocins A (1), B (2), and C (3), were defined as products of a metabolic pathway from a fern endophyte, NRRL 50135, from Papua New Guinea. NRRL 50135 initially produced 1 but ceased its production before chemical or biological evaluation could be completed. Upon transfer of the biosynthetic pathway to a model host, 1-3 were produced. All three compounds are structurally related to equisetin-type compounds, with 1 and 3 having a trans-decalin ring system, while 2 has a cis-fused decalin. All were active against Mycobacterium tuberculosis, with the trans-decalin analogues 1 and 3 exhibiting lower MICs than the cis-decalin analogue 2. Here we report the isolation, structure elucidation, and antimycobacterial activities of 1-3 from the recombinant expression as well as the isolation of 1 from the wild-type fungus NRRL 50135.

Isochromenones, isobenzofuranone, and tetrahydronaphthalenes produced by Paraphoma radicina, a fungus isolated from a freshwater habitat

Six isochromenones (1-6), clearanols F (5) and G (6), one isobenzofuranone (7), and two tetrahydronaphthalene derivatives (8 and radinaphthalenone (9)), were isolated and identified from a culture of the fungus Paraphoma radicina, which was isolated from submerged wood in a freshwater lake. Compounds 5, 6 and 9 were previously unknown. The structures were elucidated using a set of spectroscopic and spectrometric techniques; the absolute configurations of compounds 5 and 6 were determined by comparison of their experimental ECD measurements with values predicted by TDDFT calculations. Compounds 1-9 were evaluated for antimicrobial activity against an array of bacteria and fungi. The inhibitory activity of compound 4 against Staphylococcus aureus biofilm formation was evaluated.

Rexinoids isolated from Sophora tonkinensis with a gene expression profile distinct from the synthetic rexinoid bexarotene

The retinoid X receptor (RXR) plays a critical role in transcriptional regulation via formation of an RXR homodimer or heterodimers with partner nuclear receptors. Despite the numerous beneficial effects, only a limited number of naturally occurring RXR agonists are known. In this report, two prenylated flavanones (1 and 2) isolated from Sophora tonkinensis were identified as new rexinoids that preferentially activated RXRs, relative to the retinoic acid receptor. The activities of 1 and 2 were the most potent among naturally occurring rexinoids, yet 2 orders of magnitude lower than the synthetic rexinoid bexarotene. Compounds 1 and 2 activated particular RXR heterodimers in a manner similar to bexarotene. A microarray assay followed by quantitative real-time polymerase chain reaction analyses on RNAs isolated from C2C12 myotubes treated with 1 or 2 demonstrated that they significantly increased mRNA levels of lipoprotein lipase, angiopoietin-like protein 4, and heme oxygenase-1. In contrast, bexarotene preferentially potentiated transcription of genes involved in lipogenesis and lipid metabolism such as sterol regulatory element-binding protein-1, fatty acid synthase, and apolipoprotein D by a liver X receptor agonist. In this study, we have demonstrated that two newly identified naturally occurring rexinoids, 1 and 2, possess properties different from bexarotene.

Conformational analysis, UV-VIS, MESP, NLO and NMR studies of 6-methoxy-1,2,3,4-tetrahydronaphthalene

The detailed HF and B3LYP/6-311++G(d,p) comparative studies on the complete FT-IR and FT-Raman spectra of 6-methoxy-1,2,3,4-tetrahydronaphthalene [MTHN] have been studied. In view of the special properties and uses, the present investigation has been undertaken to provide a satisfactorily vibrational analysis of 6-methoxy-1,2,3,4-tetrahydronaphthalene. Therefore, a thorough Raman, IR, molecular electrostatic potential (MESP), non-linear optical (NLO) properties, UV-VIS, HOMO-LUMO and NMR spectroscopic investigation are reported complemented by B3LYP theoretical predictions with basis set 6-311++G(d,p) to provide novel insight on vibrational assignments and conformational stability of MTHN. Potential energy surface scans (PES) of the CH3 group are undertaken to shed light on the rather complicated conformational interchanges in the compound under investigation.

Cytotoxic aryltetralin lignans from fruits of Cleistanthus indochinensis

Eight new aryltetralin lignans, cleisindosides A-F (1-6), picroburseranin (7), and 7-hydroxypicropolygamain (8), were isolated from the fruits of Cleistanthus indochinensis (Euphorbiaceae). The structures of the isolates were established on the basis of their one- and two-dimensional NMR spectral data, as well as their mass spectrometric data. Compound 7 was found to have potent cytotoxicity against oral epidermoid carcinoma cells with an IC50 value of 0.062 µM, whereas glycosylation to 3 (IC50 7.5 µM) and stereochemical changes to 8 (IC50 10.8 µM) led to marked decreases in biological activity. Thus, it was determined that the C-7 and C-8' positions are critical for the biological activity of the lignans from this plant.

α-Ketoheterocycle inhibitors of fatty acid amide hydrolase: exploration of conformational constraints in the acyl side chain

A series of α-ketooxazoles containing heteroatoms embedded within conformational constraints in the C2 acyl side chain of 2 (OL-135) were synthesized and evaluated as inhibitors of fatty acid amide hydrolase (FAAH). The studies reveal that the installation of a heteroatom (O) in the conformational constraint is achievable, although the potency of these novel derivatives is reduced slightly relative to 2 and the analogous 1,2,3,4-tetrahydronaphthalene series. Interestingly, both enantiomers (R and S) of the candidate inhibitors bearing a chiral center adjacent to the electrophilic carbonyl were found to effectively inhibit FAAH.

[HPTLC fingerprint analysis of andrographolides from Andrographis paniculata]

OBJECTIVE

To establish the high-performance thin layer chromatography (HPTLC) fingerprint of andrographolides from Andrographis paniculata, and to valuate the fingerprint similarity of samples from different habitats, markets, used parts and so on.

METHODS

Chromatographic conditions were as follows: stationary phase: precoated HPTLC GF254 silica-gel plate (20 cm x 10 cm); developing solvent system: chloroform-toluene-methanol (80:10:15); Relative humidity: 42%; Color development reagent: 5% H2SO4 ethanolic solution, heating at 105 degrees C and observing the fluorescent chromatogram in a UV cabinet at 366 nm. The common patterns of HPTLC fingerprint were obtained through CHROMAP 1.5 solution software.

RESULTS

The HPTLC fingerprint of andrographolides was consisted of 9 characteristic peaks (fluorescent bands) including andrographolide, neoandrographolide and dehydroandrographolide which were chemical reference substances. The investigation and analysis of 51 batches of Andrographis paniculata showed that there were remarkable differences among different samples, so was the content of andrographolide and total lactones.

CONCLUSION

This method is simple and rapid, which can serve as an effective identification and quality assessment method for Andrographis paniculata.

Tetramic acid analogues produced by coculture of Saccharopolyspora erythraea with Fusarium pallidoroseum

Coculture of the fungus Fusarium pallidoroseum with the bacterium Saccharopolyspora erythraea was found to produce three new decalin-type tetramic acid analogues related to equisetin. The structures were determined by spectroscopic methods. The absolute configurations were established by circular dichroism spectroscopy and comparing the data with those of equisetin.

Solubilization of therapeutic agents in micellar nanomedicines

We use atomistic molecular dynamics simulations to reveal the binding mechanisms of therapeutic agents in PEG-ylated micellar nanocarriers (SSM). In our experiments, SSM in buffer solutions can solubilize either ≈11 small bexarotene molecules or ≈6 (2 in low ionic strength buffer) human vasoactive intestinal peptide (VIP) molecules. Free energy calculations reveal that molecules of the poorly water-soluble drug bexarotene can reside at the micellar ionic interface of the PEG corona, with their polar ends pointing out. Alternatively, they can reside in the alkane core center, where several bexarotene molecules can self-stabilize by forming a cluster held together by a network of hydrogen bonds. We also show that highly charged molecules, such as VIP, can be stabilized at the SSM ionic interface by Coulombic coupling between their positively charged residues and the negatively charged phosphate headgroups of the lipids. The obtained results illustrate that atomistic simulations can reveal drug solubilization character in nanocarriers and be used in efficient optimization of novel nanomedicines.

Urease inhibitory constituents from Daphne retusa

The bioassay-guided fractionation of Daphne retusa Hemsl. has led to the isolation of a new aryl tetrahydronaphthalene lignan derivative named as daphnretusic acid (1), along with six new source compounds such as 5,7-dihydroxyflavone (2), 7-hydroxyflavone (3), 6-methoxyflavone (4), (+) pinoresinol (5), (+) sesamin (6), and β-sitosterol-3-O-β-D-glucopyranoside (7). Their structures were elucidated by (1)H NMR, (13)C NMR, 1D, 2D NMR, UV, IR, and EIMS analyses. All the fractions (n-hexane, CHCl3, AcOEt, CH3OH, and water) and pure compounds (1-7) were subjected to the assay of urease and α-chymotrypsin inhibitory activities. Chloroform and methanol soluble fractions showed moderate urease inhibition. Compound 2 exhibited significant urease inhibition with IC50 value 60.4 ± 0.72 μM, whereas compounds 1 and 3-7 remained inactive during urease inhibition and α-chymotrypsin bioassays.

Modeling, synthesis, and biological evaluation of potential retinoid X receptor (RXR) selective agonists: novel analogues of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (bexarotene) and (E)-3-(3-(1,2,3,4-tetrahydro-1,1,4,4,6-pentamethylnaphthalen-7-yl)-4-hydroxyphenyl)acrylic acid (CD3254)

Three unreported analogues of 4-[1-(3,5,5,8,8-pentamethyl-5-6-7-8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (1), otherwise known as bexarotene, as well as four novel analogues of (E)-3-(3-(1,2,3,4-tetrahydro-1,1,4,4,6-pentamethylnaphthalen-7-yl)-4-hydroxyphenyl)acrylic acid (CD3254), are described and evaluated for their retinoid X receptor (RXR) selective agonism. Compound 1 has FDA approval as a treatment for cutaneous T-cell lymphoma (CTCL), although treatment with 1 can elicit side-effects by disrupting other RXR-heterodimer receptor pathways. Of the seven modeled novel compounds, all analogues stimulate RXR-regulated transcription in mammalian 2 hybrid and RXRE-mediated assays, possess comparable or elevated biological activity based on EC50 profiles, and retain similar or improved apoptotic activity in CTCL assays compared to 1. All novel compounds demonstrate selectivity for RXR and minimal crossover onto the retinoic acid receptor (RAR) compared to all-trans-retinoic acid, with select analogues also reducing inhibition of other RXR-dependent pathways (e.g., VDR-RXR). Our results demonstrate that further improvements in biological potency and selectivity of bexarotene can be achieved through rational drug design.

Qualitative and quantitative analysis of Andrographis paniculata by rapid resolution liquid chromatography/time-of-flight mass spectrometry

A rapid resolution liquid chromatography/time-of-flight tandem mass spectrometry (RRLC-TOF/MS) method was developed for qualitative and quantitative analysis of the major chemical constituents in Andrographis paniculata. Fifteen compounds, including flavonoids and diterpenoid lactones, were unambiguously or tentatively identified in 10 min by comparing their retention times and accurate masses with standards or literature data. The characteristic fragmentation patterns of flavonoids and diterpenoid lactones were summarized, and the structures of the unknown compounds were predicted. Andrographolide, dehydroandrographolide and neoandrographolide were further quantified as marker substances. It was found that the calibration curves for all analytes showed good linearity (R² > 0.9995) within the test ranges. The overall limits of detection (LODs) and limits of quantification (LOQs) were 0.02 μg/mL to 0.06 μg/mL and 0.06 μg/mL to 0.2 μg/mL, respectively. The relative standard deviations (RSDs) for intra- and inter-day precisions were below 3.3% and 4.2%, respectively. The mean recovery rates ranged from 96.7% to 104.5% with the relative standard deviations (RSDs) less than 2.72%. It is concluded that RRLC-TOF/MS is powerful and practical in qualitative and quantitative analysis of complex plant samples due to time savings, sensitivity, precision, accuracy and lowering solvent consumption.

[Advances in studies on aryltetralin lactone lignans]

Natural aryltetralin lactone lignans existed in the plants of family Berberidaceae, Acanthaceae, Burseraceae, Verbenaceae, Euphorbiaceae, etc. Due to the antineoplastic and antiviral properties, it has become a hot research topic in medicinal chemistry. This review covers extraction and isolation, biosynthesis, plant origin, and structure and spectral characteristics of natural aryltetralin lactone lignans. It will provide a useful reference for the intensive studies and rational utilization of aryltetralin lactone lignans.

Fate and removal of typical pharmaceuticals and personal care products by three different treatment processes

The presence and distribution of typical of pharmaceuticals and personal care products (PPCPs), which comprise two types of polycyclic musks (PCMs) including Galaxolide (HHCB) and Tonalide (AHTN) as well as six types of estrogens containing estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), diethylstilbestrol (DES), and bisphenol A (BPA), were investigated at two wastewater treatment plants (WWTPs) in Jiangsu, China. Only raw wastewater was treated in WWTP A while WWTP B was serving an urban-industrialized area. In the influent, the concentrations of EE2 (2193-4437ngL(-1)), E2 (1126-1170ngL(-1)), and DES (268-421ngL(-1)) were generally higher than the previously reported values, whereas the concentrations of HHCB (306-316ngL(-1)), E1 (29-129ngL(-1)), E3 (53ngL(-1)), and BPA (26-176ngL(-1)) were much lower than those reported in other previous studies. In addition, AHTN was not detected in either WWTP and E3 was not found in WWTP B. The detected processes including anaerobic/oxic process (A/O), combined orbal oxidation ditch process (C-orbal OD) and anaerobic/anoxic/anoxic/oxic membrane biological reactor (A/A/A/O-MBR) showed higher removal efficiencies for HHCB (67-71%) and EE2 (87%) than those in other previous studies. Besides, the total hydraulic retention time (HRT) ranged between 6.7 and 20.0h, sludge retention time (SRT) ranged between 8 and 23d, and water temperature ranged from 24.8 to 28.2°C. The removal efficiencies for estrogens in biological processes were related to the following factors: the level of hydrophobic estrogens, the type of removal process (C-orbal OD was consistently less efficient in removing estrogens than A/O and A/A/A/O-MBR), and a high SRT or HRT (A/A/A/O-MBR with higher SRT and HRT showed higher and more stable removal of hydrophobic estrogens).

Emerging organic contaminant removal depending on primary treatment and operational strategy in horizontal subsurface flow constructed wetlands: influence of redox

This study aimed at assessing the influence of primary treatment (hydrolytic upflow sludge blanket (HUSB) reactor vs. conventional settling) and operational strategy (alternation of saturated/unsaturated phases vs. permanently saturated) on the removal of various emerging organic contaminants (i.e. ibuprofen, diclofenac, acetaminophen, tonalide, oxybenzone, bisphenol A) in horizontal subsurface flow constructed wetlands. For that purpose, a continuous injection experiment was carried out in an experimental treatment plant for 26 days. The plant had 3 treatment lines: a control line (settler-wetland permanently saturated), a batch line (settler-wetland operated with saturate/unsaturated phases) and an anaerobic line (HUSB reactor-wetland permanently saturated). In each line, wetlands had a surface area of 2.95 m(2), a water depth of 25 cm and a granular medium D(60) = 7.3 mm, and were planted with common reed. During the study period the wetlands were operated at a hydraulic and organic load of 25 mm/d and about 4.7 g BOD/m(2)d, respectively. The injection experiment delivered very robust results that show how the occurrence of higher redox potentials within the wetland bed promotes the elimination of conventional quality parameters as well as emerging microcontaminants. Overall, removal efficiencies were always greater for the batch line than for the control and anaerobic lines, and to this respect statistically significantly differences were found for ibuprofen, diclofenac, oxybenzone and bisphenol A. As an example, ibuprofen, whose major removal mechanism has been reported to be biodegradation under aerobic conditions, showed a higher removal in the batch line (85%) than in the control (63%) and anaerobic (52%) lines. Bisphenol A showed also a great dependence on the redox status of the wetlands, finding an 89% removal rate for the batch line, as opposed to the control and anaerobic lines (79 and 65%, respectively). Furthermore, diclofenac showed a greater removal under a higher redox status (70, 48 and 32% in the batch, control and anaerobic lines). Average removal efficiencies of acetaminophen, oxybenzone and tonalide were almost >90% for the 3 treatment lines. The results of this study indicate that the efficiency of horizontal flow constructed wetland systems can be improved by using a batch operation strategy. Furthermore, we tentatively identified 4-hydroxy-diclofenac and carboxy-bisphenol A as intermediate degradation products. The higher abundance of the latter under the batch operation strategy reinforced biodegradation as a relevant bisphenol A removal pathway under higher redox conditions.

Creation of an HDAC-based yeast screening method for evaluation of marine-derived actinomycetes: discovery of streptosetin A

A histone deacetylase (HDAC)-based yeast assay employing a URA3 reporter gene was applied as a primary screen to evaluate a marine-derived actinomycete extract library and identify human class III HDAC (SIRT) inhibitors. On the basis of the bioassay-guided purification, a new compound designated as streptosetin A (1) was obtained from one of the active strains identified through the yeast assay. The gross structure of the new compound was elucidated from the 1D and 2D NMR data. The absolute stereostructure of 1 was determined based on X-ray crystal structure analysis and simulation of ECD spectra using time-dependent density functional theory calculations. This compound showed weak inhibitory activity against yeast Sir2p and human SIRT1 and SIRT2.

Two novel phenolic compounds from the rhizomes of Cyperus rotundus L

Two novel compounds, 1α-methoxy-3β-hydroxy-4α-(3′,4′-dihydroxyphenyl)-1, 2,3,4-tetrahydronaphthalin (1) and 1α,3β-dihydroxy-4α-(3′,4′-dihydroxyphenyl)-1,2,3,4-tetrahydronaphthalin (2), were isolated along with six known compounds 3-8 from the rhizomes of Cyperus rotundus. This paper reports the isolation and full spectroscopic characterization of these new compounds by NMR, UV, IR and MS data.

[Study on chemical constituents from petroleum ether-soluble parts of cones of Platycladus orientalis]

OBJECTIVE

To study chemical constituents from petroleum ether-soluble parts of cones of Platycladus orientalis.

METHODS

The compound were isolaeed by repeated column chromatography of silica gel and Sephadex LH-20. The structures were elucidated by physicochemical properties and spectrum analysis.

RESULTS

Seven constituents were isolated and identified as sandaracopimaric acid (1), 6alpha-hydroxy sandaracopimaric acid (2), ent-isopimara-8 (14), 15-dien-3beta, 19-diol (3), ent-isopimara-8 (9), 15-dien-3beta-ol (4), ent-isopimara-8 (14),15- dien-3beta-ol (5), isocupressic acid (6) and 15-acetylisocupressic acid (7).

CONCLUSION

Compounds 2 and 7 are isolated from this genus for the first time.

Oxidative and photochemical processes for the removal of galaxolide and tonalide from wastewater

Synthetic musks have been reported in wastewaters at concentrations as high as tens of micrograms per litre. The two most significant polycyclic musk fragrance compounds are 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB, trade name galaxolide®) and 7-acetyl-1,1,3,4,4,6-hexamethyltetrahydronaphthalene (AHTN, trade name tonalide®). We report the result of several irradiation and advanced oxidation processes carried out on samples of the effluent of a wastewater treatment plant located in Alcalá de Henares, Madrid. Wastewater samples were pre-ozonated and spiked with 500 ng/L of tonalide or galaxolide in order to obtain final concentrations in the same order as the raw effluent. The treatments assayed were ozonation with and without the addition of hydrogen peroxide (O₃, O₃/H₂O₂), ultraviolet (254 nm low pressure mercury lamp) and xenon-arc visible light irradiation alone and in combination with ozone (UV, O₃/UV, Xe, O₃/Xe) and visible light photocatalytic oxidation using a Ce-doped titanium dioxide photocatalyst performed under continuous oxygen or ozone gas bubbling (O₂/Xe/Ce-TiO₂, O₃/Xe/Ce-TiO₂). In all cases, samples taken at different contact times up to 15 min were analyzed. An analytical method based on stir bar sorptive extraction (SBSE), followed by comprehensive two-dimensional gas chromatography (SBSE-GC × GC-TOF-MS), was used for the automatic searching and evaluation of the synthetic musks and other nonpolar or semipolar contaminants in the wastewater samples. In all cases tonalide was more easily removed than galaxolide. The best results for the latter (more than 75% removal after 5 min on stream) were obtained from ozonation (O₃) and visible light photocatalytic ozonation (O₃/Xe/Ce-TiO₂). A significant removal of both pollutants (∼60% after 15 min) was also obtained during visible light photocatalysis (O₂/Xe/Ce-TiO₂). UV radiation was able to deplete tonalide (+90%) after 15 min but only reduced the concentration of galaxolide to about half of its initial concentration. The toxicity of treated samples decreased for O₃/UV and O₃/Ce-TiO₂, but increased during irradiation processes UV, Xe and Xe/Ce-TiO₂. Ozone treatments tend to decrease toxicity up to a certain dosage, from which point the presence of toxic transformation products has adverse effects on aquatic microorganisms.

Mechanism of tetralin ring opening and contraction over bifunctional Ir/SiO₂-Al₂O₃ Catalysts

The development of cleaner fuels from conventional resources requires the finding of new hydrotreatment processes able to improve the combustion performances of fuels and limit undesirable emissions. In the context of gas oil upgrading by selective ring opening, we have investigated the hydroconversion of tetralin over iridium nanoparticles supported on amorphous silica-alumina. The conversion of tetralin leads to hydrogenation, ring-contraction, and ring-opening products. The selectivity to ring-opening/-contraction products (ROCPs) increases linearly with the acid-metal site ratio and can be tuned by modifying the metal loading, the metal nanoparticle size, or the support composition. From the combination of catalytic tests at variable conversion and the products identification by two-dimensional gas chromatography, a mechanistic reaction scheme has been established. Aromatic ROCPs are formed through purely acidic steps, whereas the formation of saturated ROCPs mostly involves bifunctional reaction steps. Iridium-catalyzed hydrogenolysis appears to be a minor pathway with respect to iridium-catalyzed hydrogenation and Brønsted acid catalyzed isomerization.

Modeling, synthesis and biological evaluation of potential retinoid X receptor-selective agonists: novel halogenated analogues of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (bexarotene)

The synthesis of halogenated analogues of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (1), known commonly as bexarotene, and their evaluation for retinoid X receptor (RXR)-specific agonist performance is described. Compound 1 is FDA approved to treat cutaneous T-cell lymphoma (CTCL); however, bexarotene treatment can induce hypothyroidism and elevated triglyceride levels, presumably by disrupting RXR heterodimer pathways for other nuclear receptors. The novel halogenated analogues in this study were modeled and assessed for their ability to bind to RXR and stimulate RXR homodimerization in an RXRE-mediated transcriptional assay as well as an RXR mammalian-2-hybrid assay. In an array of eight novel compounds, four analogues were discovered to promote RXR-mediated transcription with EC(50) values similar to that of 1 and are selective RXR agonists. Our approach also uncovered a periodic trend of increased binding and homodimerization of RXR when substituting a halogen atom for a proton ortho to the carboxylic acid on 1.

Transformation products and reaction kinetics of fragrances in advanced wastewater treatment with ozone

The reaction of the fragrance compounds 4,6,6,7,8,8-hexamethyl-1,3,4,7-tetrahydrocyclopenta[g]isochromene (HHCB), 1-(3,5,5,6,8,8-hexamethyl-6,7-dihydronaphthalen-2-yl)ethanone (AHTN), 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene (musk xylene/MX), 1-(4-tert-butyl-2,6-dimethyl-3,5-dinitrophenyl)ethanone (musk ketone/MK), and 1-(2,3,8,8-tetramethyl-1,3,4,5,6,7-hexahydronaphthalen-2-yl)ethanone (OTNE) with ozone in tap water as well as waste water treatment plant (WWTP) effluents is described. Several transformation products are characterized by means of gas chromatography coupled to mass spectrometry. One transformation product (HHCB-Lactone) was confirmed by means of a true standard. Musk xylene and musk ketone do not react with ozone under the conditions used in this study. AHTN and HHCB reacted slowly to a multitude of transformation products, while OTNE reacted quickly to several stable transformation products. The reaction constants and half lives are used to predict removal efficiencies for full scale reactors.

Diterpenes from the Hainan soft coral Lobophytum cristatum Tixier-Durivault

Two new prenylgermacrane-type diterpenoids, lobophytumins A and B (1 and 2), two new prenyleudesmane-type diterpenoids, lobophytumins C and D (3 and 4), and two new spatane-type diterpenoids, lobophytumins E and F (5 and 6), were isolated from the Hainan soft coral Lobophytum cristatum Tixier-Durivault. Their structures, including relative configuration, were elucidated by detailed analysis of spectroscopic data and by comparison with related known compounds. In addition, the absolute configuration of lobophytumin C (3) was tentatively assigned by comparing its specific rotation with that of the closely related model compound (-)-β-selinene (8). On the basis of biogenetic considerations, the absolute configurations of lobophytumins A, B, and D-F were also tentatively suggested. This is the first report of spatane-type diterpenoids from a soft coral source. The present work supports Faulkner's proposal of prenylgermacrene as the precursor of many diterpenes. In a bioassay, lobophytumins C and D (3 and 4) showed weak in vitro cytotoxicities against the tumor cell lines A-549 and HCT-116.

Concentrations, distribution, and bioaccumulation of synthetic musks in the Haihe River of China

Seven typical synthetic musks (SMs) in the samples from the surface water, sediment and fish of the Haihe River were measured. The SM concentrations in the sediment and surface water of the Haihe River were significantly lower than those in the Dagu Drainage River and Chentaizi Drainage River (p<0.05). Along the flow direction, the SM concentrations in surface water and sediment tended to increase from the upstream to the downstream of Dagu Drainage River. The Bioaccumulation factors (BAFs) of galaxolide (HHCB) and tonalide (AHTN) were calculated at high levels in the muscles of crucian carp, common carp, and silver carp. Most of the biota-sediment accumulation factors (BSAFs) for HHCB and AHTN were higher than 1.7, suggesting magnification possibly exist in the musk bioaccumulations of the three fishes in the Haihe River. No significant differences in HHCB/AHTN ratios were observed among the water, fish, and sediment samples (p>0.05). However, the HHCB/AHTN values in the Haihe River were much lower than those in the Dagu Drainage River and Chentaizi Drainage River (p<0.05). Compared with several typical persistent organic pollutants (POPs), the musk concentrations were higher or comparable in the Haihe River.

Nanostructured carbon-metal oxide hybrids as amphiphilic emulsion catalysts

Nanohybrids composed of "onion-like" carbon, single-walled (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) fused to silica or alumina particles have been compared as stabilizers of water/oil emulsions and interfacial catalysts. The amphiphilic character of these nanohybrids makes them effective in stabilizing emulsions (up to 85 % of total volume) comprising of small droplets (less than 40 μm). Furthermore, these nanohybrids have been used as supports for transition metal particles (palladium and copper) to catalyze reactions at the water/oil interface. Three different reaction systems have been conducted in the emulsions to demonstrate the principle: 1) hydrogenation of phenanthrene; 2) hydrogenation of glutaraldehyde and benzaldehyde; 3) oxidation of tetralin. Comparison of the maximum conversions achieved in emulsions as opposed to the single phase, together with much better control of selectivity in the two-phase system shows the benefits of using these nanohybrid catalysts.

Controlling the facial selectivity of asymmetric [4+2] cyclo-additions: a concise synthesis of the cis-decalin core structure of superstolides A and B

Regio-, stereo-, and facial selective [4 + 2] cycloadditions between highly activated vinyl sulfones and 1,3-dienes derived from (R)-4-tert-butyldimethylsilyloxy-2-cyclohexen-1-one provide a powerful approach for the asymmetric synthesis of compounds containing the bicyclo[2.2.2]octanone carbon skeleton. This new methodology has been successfully applied to the asymmetric synthesis of the cis-decalin core structure of the potent anticancer marine natural products superstolides A and B.

Extension of lifespan in C. elegans by naphthoquinones that act through stress hormesis mechanisms

Hormesis occurs when a low level stress elicits adaptive beneficial responses that protect against subsequent exposure to severe stress. Recent findings suggest that mild oxidative and thermal stress can extend lifespan by hormetic mechanisms. Here we show that the botanical pesticide plumbagin, while toxic to C. elegans nematodes at high doses, extends lifespan at low doses. Because plumbagin is a naphthoquinone that can generate free radicals in vivo, we investigated whether it extends lifespan by activating an adaptive cellular stress response pathway. The C. elegans cap‘n’collar (CNC) transcription factor, SKN-1, mediates protective responses to oxidative stress. Genetic analysis showed that skn-1 activity is required for lifespan extension by low-dose plumbagin in C. elegans. Further screening of a series of plumbagin analogs identified three additional naphthoquinones that could induce SKN-1 targets in C. elegans. Naphthazarin showed skn-1dependent lifespan extension, over an extended dose range compared to plumbagin, while the other naphthoquinones, oxoline and menadione, had differing effects on C. elegans survival and failed to activate ARE reporter expression in cultured mammalian cells. Our findings reveal the potential for low doses of naturally occurring naphthoquinones to extend lifespan by engaging a specific adaptive cellular stress response pathway.

Structure elucidation and complete NMR spectral assignment of an unusual aromatic monacolin analog from Monascus purpureus-fermented rice

One unusual aromatic monacolin analog, monacophenyl, was isolated from the ethanolic extract of Monascus purpureus-fermented rice. Its structure was completely and unambiguously assigned by one- and two-dimensional NMR techniques ((1)H NMR, (13)C NMR, HSQC, HMBC and NOESY) and high-resolution ESI-MS spectrometry.

Cytochrome P450 3A4 inhibitory constituents of the wood of Taxus yunnanensis

From the aqueous extract of the wood of Taxus yunnanensis, which showed cytochrome P450 3A4 (CYP3A4) inhibition, a new isoflavan [(3S,4R)-4'-hydroxy-6,3'-dimethoxyisoflavan-4-ol (1)], a new degraded lignan [2,3-bis(hydroxymethyl)-7-hydroxy-6-methoxy-1-tetralone (2)], and a new lignan [(7R)-7-hydroxytaxiresinol (3)] were isolated, together with nine known lignans. Among the isolates obtained, α-conidendrin (12) showed strong CYP3A4 inhibition with an IC(50) value of 0.2 μM.