Structure Elucidation and Confirmation of Phloroglucinols from the Roots of Garcinia dauphinensis by Comparison of Experimental and Calculated ECD Spectra and Specific Rotations.

Eight phloroglucinols from Garcinia dauphinensis were recently reported to have good to moderate antiplasmodial and anticancer activities, consistent with other phloroglucinol derivatives isolated from natural sources. Chiroptical properties were previously calculated and compared to experimental data for compound 2 as a means to deduce its absolute configuration. Tentative assignments for the remaining compounds were also reported based on these data. In order to arrive at stereochemical assignments for phloroglucinols 1 and 3-8, ECD spectra and specific rotations were computed for all stereoisomers of each compound. Molecular orbital analyses were also carried out for the most energetically favorable conformers of each compound. Absolute configurations are reported for all eight phloroglucinols for the first time.

Phloroglucinols from the Roots of Garcinia dauphinensis and Their Antiproliferative and Antiplasmodial Activities.

Garcinia dauphinensis is a previously uninvestigated endemic plant species of Madagascar. The new phloroglucinols dauphinols A-F and 3'-methylhyperjovoinol B (1-7) and six known phloroglucinols (8-13) together with tocotrienol 14 and the three triterpenoids 15-17 were isolated from an ethanolic extract of G. dauphinensis roots using various chromatographic techniques. The structures of the isolated compounds were elucidated by NMR, MS, optical rotation, and ECD data. Theoretical ECD spectra and specific rotations for 2 were calculated and compared to experimental data in order to assign its absolute configuration. Among the compounds tested, 1 showed the most promising growth inhibitory activity against A2870 ovarian cancer cells, with IC50 = 4.5 ± 0.9 µM, while 2 had good antiplasmodial activity against the Dd2 drug-resistant strain of Plasmodium falciparum, with IC50 = 0.8 ± 0.1 µM.

Synthesis of rocaglamide derivatives and evaluation of their Wnt signal inhibitory activities.

Rocaglamides are bioactive natural compounds which have a cyclopenta[b]benzofuran core structure. The total synthesis of a reported natural product, 3'-hydroxymethylrocaglate (5), was achieved using [3 + 2] cycloaddition between 3-hydroxyflavone and methyl cinnamate. We also describe the synthesis of rocaglamide heterocycle derivatives and evaluate their Wnt signal inhibitory activities. Compounds 4, 5, 22a, 22b, 22c and 23c showed potent Wnt signal inhibitory activity.

Natural compounds with Wnt signal modulating activity.

Covering: up to 2015 The Wnt signalling pathway is essential in many biological processes. The Wnt signal is associated with several diseases, particularly cancer and neurodegenerative diseases. Recently, high-throughput screening systems have been developed to rapidly identify compounds, including natural compounds, that target the Wnt signal. Some studies on natural modulators of the Wnt signal have also suggested their possible target. This review highlights some important natural compounds reported to regulate Wnt activity and describes their possible mechanism of action.

Phenolic compounds from the bark of Oroxylum indicum activate the Ngn2 promoter.

A reporter gene assay that detects neurogenin 2 (Ngn2) promoter activity was utilized to identify compounds that induce neuronal differentiation. Ngn2 is a basic helix-loop-helix transcription factor that activates transcription of pro-neural genes. Using this assay system and an activity-guided approach, seven phenolic compounds were isolated from the methanol extract of Oroxylum indicum: 1 oroxylin A, 2 chrysin, 3 hispidulin, 4 baicalein, 5 apigenin, 6 baicalin, and 7 isoverbascoside. Compounds 1 and 2 induced an estimated 2.7-fold increase in Ngn2 promoter activity, whereas 3 increased the activity by 2.5-fold. Furthermore, 1 and 2 enhanced neuronal differentiation of C17.2 cells, which are multipotent stem cells.

Scopadulciol, Isolated from Scoparia dulcis, Induces ß-Catenin Degradation and Overcomes Tumor Necrosis Factor-Related Apoptosis Ligand Resistance in AGS Human Gastric Adenocarcinoma Cells.

Scopadulciol (1), a scopadulan-type diterpenoid, was isolated from Scoparia dulcis along with three other compounds (2-4) by an activity-guided approach using the TCF reporter (TOP) luciferase-based assay system. A fluorometric microculture cytotoxicity assay (FMCA) revealed that compound 1 was cytotoxic to AGS human gastric adenocarcinoma cells. The treatment of AGS cells with 1 decreased ß-catenin levels and also inhibited its nuclear localization. The pretreatment of AGS cells with a proteasome inhibitor, either MG132 or epoxomicin, protected against the degradation of ß-catenin induced by 1. The 1-induced degradation of ß-catenin was also abrogated in the presence of pifithrin-α, an inhibitor of p53 transcriptional activity. Compound 1 inhibited TOP activity in AGS cells and downregulated the protein levels of cyclin D1, c-myc, and survivin. Compound 1 also sensitized AGS cells to tumor necrosis factor-related apoptosis ligand (TRAIL)-induced apoptosis by increasing the levels of the death receptors, DR4 and DR5, and decreasing the level of the antiapoptotic protein Bcl-2. Collectively, our results demonstrated that 1 induced the p53- and proteasome-dependent degradation of ß-catenin, which resulted in the inhibition of TCF/ß-catenin transcription in AGS cells. Furthermore, 1 enhanced apoptosis in TRAIL-resistant AGS when combined with TRAIL.

Morphological and physiological responses of lowland purple nutsedge (Cyperus rotundus L.) to flooding.

BACKGROUND AND AIMS: Purple nutsedge (Cyperus rotundus L.) is a major weed of upland crops and vegetables. Recently, a flood-tolerant ecotype evolved as a serious weed in lowland rice. This study attempted to establish the putative growth and physiological features that led to this shift in adaptation. METHODOLOGY: Tubers of upland C. rotundus (ULCR) and lowland C. rotundus (LLCR) ecotypes were collected from their native habitats and maintained under the respective growth conditions in a greenhouse. Five experiments were conducted to assess the variation between the two ecotypes in germination, growth and tuber morphology when grown in their native or 'switched' conditions. Carbohydrate storage and mobilization, and variation in anaerobic respiration under hypoxia were compared. PRINCIPAL RESULTS: Tubers of LLCR were larger than those of ULCR, with higher carbohydrate content, and larger tubers developed with increasing floodwater depth. Stems of LLCR had larger diameter and proportionally larger air spaces than those of ULCR: a method of aerating submerged plant parts. The LLCR ecotype can also mobilize and use carbohydrate reserves under hypoxia, and it maintained relatively lower and steadier activity of alcohol dehydrogenase (ADH) as a measure of sustained anaerobic respiration. In contrast, ADH activity in ULCR increased faster upon a shift to hypoxia and then sharply decreased, suggesting depletion of available soluble sugar substrates. The LLCR ecotype also maintained lower lactate dehydrogenase activity under flooded conditions, which could reduce chances of cellular acidosis. CONCLUSIONS: These adaptive traits in the LLCR ecotype were expressed constitutively, but some of them, such as tuber growth and aerenchyma development, are enhanced with stress severity. The LLCR ecotype attained numerous adaptive traits that could have evolved as a consequence of natural evolution or repeated management practices, and alternative strategies are necessary because flooding is no longer a feasible management option.

The mechanisms of carbon monoxide production by inhalational agents.

Carbon monoxide can be formed when volatile anaesthetic agents such as desflurane and sevoflurane are used with anaesthetic breathing systems containing carbon dioxide absorbents. This review describes the possible chemical processes involved and summarises the experimental and clinical evidence for the generation of carbon monoxide. We emphasise the different conditions that were used in the experimental work, and explain some of the features of the clinical reports. Finally, we provide guidelines for the prevention and detection of this complication.

Time course of inhaled anaesthetic drug delivery using a new multifunctional closed-circuit anaesthesia ventilator. In vitro comparison with a classical anaesthesia machine.

BACKGROUND: The aim of this study was to detail the time-course, defined as the changes in end-tidal drug concentration with time, and consumption of inhaled anaesthetics when using a multifunctional closed-circuit anaesthesia machine in various drug delivery modes, and to compare it with a classical anaesthesia machine using an out-of-circle vaporizer under high and low fresh gas flow conditions. METHODS: Using an artificial test lung, sevoflurane and desflurane time-course and consumption were compared when using the Zeus apparatus (Dräger, Lubeck, Germany) with direct injection of inhaled anaesthetics or the Primus apparatus (Dräger, Lubeck, Germany) using a classical out-of-circle vaporizer. Anaesthetics were targeted at 1 and 2 MAC end-tidal during 15 min. For both apparatus, out-of-circle high and low fresh gas control (FGC) and for Zeus, auto-control (AC) modes (fixed fresh gas flow at 6 and 1 litre min(-1) and uptake mode) were compared. Time to reach target, initial overshoot and stability at target, and wash-out times were compared. RESULTS: In FGC, an initial overshoot in end-tidal drug concentration is seen when using 6 litre min(-1) fresh gas flow and a slower time course is observed when using only 1 litre min(-1) in both apparatus. In auto-control mode, the time course of both sevoflurane and desflurane was very fast and not influenced by the changes in fresh gas flow. No overshoot at target was seen. At all settings, the wash-out times were faster when using Zeus than Primus. Inhaled anaesthetic consumption was lowest with the Zeus ventilator in uptake AC mode. CONCLUSION: A combination of the fastest time course and lowest consumption of sevoflurane and desflurane was found when using the Zeus apparatus in AC uptake mode.

Production of compound A and carbon monoxide in circle systems: an in vitro comparison of two carbon dioxide absorbents.

Two new generation carbon dioxide absorbents, DrägerSorb Free and Amsorb Plus, were studied in vitro for formation of compound A or carbon monoxide, during minimal gas flow (500 ml x min(-1)) with sevoflurane or desflurane. Compound A was assessed by gas chromatography/mass spectrometry and carbon monoxide with continuous infrared spectrometry. Fresh and dehydrated absorbents were studied. Mean (SD) time till exhaustion (inspiratory carbon dioxide concentration >or= 1 kPa) with fresh absorbents was longer with DrägerSorb Free (1233 (55) min) than with Amsorb Plus (1025 (55) min; p < 0.01). For both absorbents, values of compound A were < 1 ppm and therefore below clinically significant levels, but were up to 0.25 ppm higher with DrägerSorb Free than with Amsorb Plus. Using dehydrated absorbents, values of compound A were about 50% lower than with fresh absorbents and were identical for DrägerSorb Free and Amsorb Plus. With dehydrated absorbents, no detectable carbon monoxide was found with desflurane.

Only carbon dioxide absorbents free of both NaOH and KOH do not generate compound A during in vitro closed-system sevoflurane: evaluation of five absorbents.

BACKGROUND: Insufficient data exist on the production of compound A during closed-system sevoflurane administration with newer carbon dioxide absorbents. METHODS: A modified PhysioFlex apparatus (Dräger, Lübeck, Germany) was connected to an artificial test lung (inflow at the top of the bellow approximately/= 160 ml/min CO2; outflow at the Y piece of the lung model approximately/= 200 ml/min, simulating oxygen consumption). Ventilation was set to obtain an end-tidal carbon dioxide partial pressure of approximately 40 mmHg. Various fresh carbon dioxide absorbents were used: Sodasorb (n = 6), Sofnolime (n = 6), and potassium hydroxide (KOH)-free Sodasorb (n = 7), Amsorb (n = 7), and lithium hydroxide (n = 7). After baseline analysis, liquid sevoflurane was injected into the circuit by syringe pump to obtain 2.1% end-tidal concentration for 240 min. At baseline and at regular intervals thereafter, end-tidal carbon dioxide partial pressure, end-tidal sevoflurane concentration, and canister inflow (T degrees(in)) and canister outflow (T degrees(out)) temperatures were measured. To measure compound Ainsp concentration in the inspired gas of the breathing circuit, 2-ml gas samples were taken and analyzed by capillary gas chromatography plus mass spectrometry. RESULTS: The median (minimum-maximum) highest compound Ainsp concentrations over the entire period were, in decreasing order: 38.3 (28.4-44.2)* (Sofnolime), 30.1 (23.9-43.7) (KOH-free Sodasorb), 23.3 (20.0-29.2) (Sodasorb), 1.6 (1.3-2.1)* (lithium hydroxide), and 1.3 (1.1-1.8)* (Amsorb) parts per million (*P < 0.01 vs. Sodasorb). After reaching their peak concentration, a decrease for Sofnolime, KOH-free Sodasorb, and Sodasorb until 240 min was found. The median (minimum-maximum) highest values for T degrees(out) were 39 (38-40), 40 (39-42), 41 (40-42), 46 (44-48)*, and 39 (38-41) degrees C (*P < 0.01 vs. Sodasorb), respectively. CONCLUSIONS: With KOH-free (but sodium hydroxide [NaOH]-containing) soda limes even higher compound A concentrations are recorded than with standard Sodasorb. Only by eliminating KOH as well as NaOH from the absorbent (Amsorb and lithium hydroxide) is no compound A produced.

Compound A production from sevoflurane is not less when KOH-free absorbent is used in a closed-circuit lung model system.

In an in vitro study, less compound A was formed when a KOH-free carbon dioxide absorbent was used. To confirm this observation we used a lung model in which carbon dioxide was fed in at 160 ml min(-1) and sampling gas was taken out for analysis at 200 ml min(-1); ventilation aimed for a PE'CO2 of 5.4 kPa. The soda lime canister temperatures in the inflow and outflow ports (Tin and Tout) were recorded. In six runs of 240 min each, a standard soda lime, Sodasorb (Grace, Epernon, France) was used and in eight runs KOH-free Sofnolime (Molecular Products, Thaxted, UK) was used. Liquid sevoflurane was injected using a syringe pump to obtain 2.1% E'. Compound A was measured by capillary gas chromatography combined with mass spectrometry. Median (range) compound Ainsp increased to a maximum of 22.7 (7.9) ppm for Sodasorb and 33.1 (20) for Sofnolime at 60 min and decreased thereafter; the difference between groups was significant (P<0.05) at each time of analysis up to 240 min. The canister temperatures were similar in both groups and increased to approximately 40 degrees C at 240 min. Contrary to expectation, compound A concentrations were greater with the KOH-free absorbent despite similar canister temperatures with both absorbents.

Quantitative determination of vapor-phase compound A in sevoflurane anesthesia using gas chromatography-mass spectrometry.

BACKGROUND: During low-flow or closed-circuit anesthesia with the fluorinated inhalation anesthetic sevoflurane, compound A, an olefinic degradation product with known nephrotoxicity in rats, is generated on contact with alkaline CO(2) adsorbents. To evaluate compound A formation and thus potential sevoflurane toxicity, a reliable and reproducible assay for quantitative vapor-phase compound A determination was developed. METHODS: Compound A concentrations were measured by fully automated capillary gas chromatography-mass spectrometry with cryofocusing. Calibrators of compound A in the vapor phase were prepared from liquid volumetric dilutions of stock solutions of compound A and sevoflurane in ethyl acetate. 1,1,1-Trifluoro-2-iodoethane was chosen as an internal standard. The resulting quantitative method was fully validated. RESULTS: A linear response over a clinically useful concentration interval (0.3-75 microL/L) was obtained. Specificity, sensitivity, and accuracy conformed with current analytical requirements. The CVs were 4.1-10%, the limit of detection was 0.1 microL/L, and the limit of quantification was 0.3 microL/L. Analytical recoveries were 100.6% +/- 10.1%, 102.5% +/- 7.3%, and 99.0% +/- 4.1% at 0.5, 10, and 75 microL/L, respectively. The method described was used to determine compound A concentrations during simulated closed-circuit conditions. Some of the resulting data are included, illustrating the practical applicability of the proposed analytical approach. CONCLUSIONS: A simple, fully automated, and reliable quantitative analytical method for determination of compound A in air was developed. A solution was established for sampling, calibration, and chromatographic separation of volatiles in an area complicated by limited availability of sample volume and low concentrations of the analyte.

In vitro compound A formation in a computer-controlled closed-circuit anesthetic apparatus. Comparison with a classical valve circuit.

BACKGROUND: Few data exist on compound A during sevoflurane anesthesia when using closed-circuit conditions and sodalime with modern computer-controlled liquid injection. METHODS: A PhysioFlex apparatus (Dräger, Lübeck, Germany) was connected to an artificial test lung (inflow approximately 160 ml/min carbon dioxide, outflow approximately 200 ml/min, simulating oxygen consumption). Ventilation was set to obtain an end-tidal carbon dioxide partial pressure (Petco2) approximately 40 mmHg. Canister inflow (T degrees in) and outflow (T degrees out) temperatures were measured. Fresh sodalime and charcoal were used. After baseline analysis, sevoflurane concentration was set at 2.1% end-tidal for 120 min. At baseline and at regular intervals thereafter, Petco2, end-tidal sevoflurane, T degrees in, and T degrees out were measured. For inspiratory and expiratory compound A determination, samples of 2-ml gas were taken. These data were compared with those of a classical valve-containing closed-circuit machine. Ten runs were performed in each set-up. RESULTS: Inspired compound A concentrations increased from undetectable to peak at 6.0 (SD 1.3) and 14.3 (SD 2.5) ppm (P < 0.05), and maximal temperature in the upper outflow part of the absorbent canister was 24.3 degrees C (SD 3.6) and 39.8 degrees C (SD 1.2) (P < 0.05) in the PhysioFlex and valve circuit machines, respectively. Differences between the two machines in compound A concentrations and absorbent canister temperature at the inflow and outflow regions were significantly different (P < 0.05) at all times after 5 min. CONCLUSION: Compound A concentrations in the high-flow (70 l/min), closed-circuit PhysioFlex machine were significantly lower than in conventional, valve-based machines during closed-circuit conditions. Lower absorbent temperatures, resulting from the high flow, appear to account for the lower compound A formation.

Influence of intravenous clonidine pretreatment on anesthetic requirements during bispectral EEG-guided sevoflurane anesthesia.

STUDY OBJECTIVE: To assess the anesthetic effects of clonidine during sevoflurane anesthesia guided by the bispectral index (BIS), which is a processed EEG variable correlated with anesthetic-hypnotic depth. DESIGN: Placebo-controlled, double-blind clinical trial. SETTINGS: Elective laparoscopic surgery. PATIENTS: 60 ASA physical status I patients scheduled for laparoscopic surgery. INTERVENTIONS: Patients received either clonidine (3 micrograms/kg, 15 min before induction) or placebo premedication for a sevoflurane-induced and sevoflurane-maintained anesthesia. Sevoflurane was titrated against a BIS held between 40 and 50. Analgesia was provided by local infiltration with bupivacaine. Need for postoperative analgesia was recorded. RESULTS AND CONCLUSION: Mean sevoflurane requirements were not lower with clonidine pretreatment. There was statistically better perioperative hemodynamic stability (i.e., fewer episodes of hypertension and tachycardia) without clinical relevance. A decreased need for postoperative analgesia was observed.

Comparison of plasma compartment versus two methods for effect compartment--controlled target-controlled infusion for propofol.

BACKGROUND: Target-controlled infusion (TCI) systems can control the concentration in the plasma or at the site of drug effect. A TCI system that targets the effect site should be able to accurately predict the time course of drug effect. The authors tested this by comparing the performance of three control algorithms: plasmacontrol TCI versus two algorithms for effect-site control TCI. METHODS: One-hundred twenty healthy women patients received propofol via TCI for 12-min at a target concentration of 5.4 microg/ml. In all three groups, the plasma concentrations were computed using pharmacokinetics previously reported. In group I, the TCI device controlled the plasma concentration. In groups II and III, the TCI device controlled the effect-site concentration. In group II, the effect site was computed using a half-life for plasma effect-site equilibration (t1/2k(eo)) of 3.5 min. In group III, plasma effect-site equilibration rate constant (k(eo)) was computed to yield a time to peak effect of 1.6 min after bolus injection, yielding a t1/2keo of 34 s. the time course of propofol was measured using the bispectral index. Blood pressure, ventilation, and time of loss of consciousness were measured. RESULTS: The time course of propofol drug effect, as measured by the bispectral index, was best predicted in group III. Targeting the effect-site concentration shortened the time to loss of consciousness compared with the targeting plasma concentration without causing hypotension. The incidence of apnea was less in group III than in group II. CONCLUSION: Effect compartment-controlled TCI can be safely applied in clinical practice. A biophase model combining the Marsh kinetics and a time to peak effect of 1.6 min accurately predicted the time course of propofol drug effect.

Influence of methane on infrared gas analysis of volatile anesthetics.

Contemporary multigas analyzers determine anesthetic gas concentrations using (near) infrared analysis at either 3.3 or 8-9 microns. Methane also absorbs infrared light at 3.3 microns, but not at 8-9 microns. Consequently, erroneous anesthetic agent readings may result when methane is present in the circuit (e.g. during closed circuit anesthesia), potentially compromising patient safety. We have analyzed in laboratory conditions the influence of different known methane concentrations (100, 500 and 1000 ppm) on the gas-analysis readings provided by some clinical monitoring devices that use infrared absorption for the measurement of inhalation anesthetic concentration. At 3.3 microns wavelength the influence on the measurement of halothane was important, whereas the influence on that of enflurane and isoflurane was less pronounced. For desflurane and sevoflurane measurements, the influence of methane at 3.3 microns wavelength proved to be minimal. At higher wavelengths (8-9 microns) no influence of methane could be demonstrated.

Transition time: a new parameter coinciding with fair intubating conditions.

With rocuronium optimal intubating conditions are earlier achieved than the adductor pollicis muscle onset time. Using the transition time we defined a better parameter for clinical relaxation. The onset of relaxation was determined in 20 patients. After a stable response was achieved with a 0.1 Hz single twitch stimulation 0.60 mg/kg rocuronium was injected. The three different stades during the onset of relaxation were determined. These are the lag time, transition time (transition between second and third phase) and onset time. Whether the transiton time corresponds with optimal intubating conditions was evaluated in 40 other patients. The median transition time was 67.4 (P25:52.5, P75:76.3) seconds with a corresponding relaxation of 76.2 (P25:81.4, P75:70.7)%. The intubating conditions were significantly better at a relaxation level corresponding with the transition time. We conclude that the transition time approximates the intubating time and corresponds with fair intubating conditions. This parameter can be preferred to define the moment with optimal intubating conditions.

The onset of neuromuscular block at the masseter muscle as a predictor of optimal intubating conditions with rocuronium.

After an intubating dose of rocuronium satisfactory intubating conditions are achieved before the onset time at the adductor pollicis. We examined the possibility that measurement of the relaxation of the masseter muscle is a more appropriate guide when determining the intubating time. Simultaneous accelerometry with a 0.1-Hz single twitch stimulation of the chin and thumb was performed in 20 patients after 0.6 mg kg-1 rocuronium. We observed a significantly more brief mean lag time and onset time at the masseter muscle (22.5 and 61 vs. 32.5 and 160 s). The corresponding mean relaxation at the onset time was also significantly more pronounced at the masseter muscle (99.6 vs. 97.6%). A mean onset time at the masseter muscle of 61 s as produced by rocuronium corresponds clinically with excellent or good intubating conditions. From these results, we suggest that measurement of the onset time of muscle relaxation at the masseter muscle appears to be a better predictor of good intubating conditions than measurements made using the adductor pollicis muscle after administration of rocuronium.