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The pathophysiological link between adiposity and blood pressure is not completely understood, and evidence suggests an influence of sex and genetic determinants. We aimed to identify the relationship between adiposity and blood pressure, independent of a robust set of lifestyle and metabolic factors, and to examine the modulating role of sex and Angiotensin-Converting Enzyme (ACE) insertion/deletion (I/D) polymorphisms. In the Relationship Between Insulin Sensitivity and Cardiovascular Disease (RISC) study cohort, 1211 normotensive individuals, aged 30 to 60 years and followed-up after 3.3 years, were characterized for lifestyle and metabolic factors, body composition, and ACE genotype. Body mass index (BMI) and waist circumference (WC) were independently associated with mean arterial pressure, with a stronger relationship in women than men (BMI: r =0.40 versus 0.30; WC: r =0.40 versus 0.30, both P ID and II ACE genotypes in both sexes ( P ACE genotype only in women ( P =0.03). A 5 cm larger WC at baseline increased the risk of developing hypertension at follow-up only in women (odds ratio, 1.56 [95% CI, 1.15–2.10], P =0.004) and in II genotype carriers (odds ratio, 1.87 [95% CI, 1.09–3.20], P =0.023). The hypertensive effect of adiposity is more pronounced in women and in people carrying the II variant of the ACE genotype, a marker of salt sensitivity.

A measure that identifies patients who are at high risk of mortality after prolonged ventilation will help physicians communicate prognoses to patients or surrogate decision makers. Our objective was to develop and validate a prognostic model for 1-yr mortality in patients ventilated for 21 days or more.The authors conducted a prospective cohort study.The study took place at a university-based tertiary care hospital.Three hundred consecutive medical, surgical, and trauma patients requiring mechanical ventilation for at least 21 days were prospectively enrolled.Predictive variables were measured on day 21 of ventilation for the first 200 patients and entered into logistic regression models with 1-yr and 3-mo mortality as outcomes. Final models were validated using data from 100 subsequent patients. One-year mortality was 51% in the development set and 58% in the validation set. Independent predictors of mortality included requirement for vasopressors, hemodialysis, platelet countor = 150 x 10(9)/L, and ageor = 50 yrs. Areas under the receiver operating characteristic curve for the development model and validation model were .82 (SE .03) and .82 (SE .05), respectively. The model had sensitivity of .42 (SE .12) and specificity of .99 (SE .01) for identifying patients who hador = 90% risk of death at 1 yr. Observed mortality was highly consistent with both 3- and 12-mo predicted mortality. These four predictive variables can be used in a simple prognostic score that clearly identifies low-risk patients (no risk factors, 15% mortality) and high-risk patients (three or four risk factors, 97% mortality).Simple clinical variables measured on day 21 of mechanical ventilation can identify patients at highest and lowest risk of death from prolonged ventilation.

Reaction of coniferyl alcohol or sinapyl alcohol with β-O-4 dimeric model compounds in the presence of manganese(III), copper(II), or vanadium(V) gave trimeric compounds that served as superior models for13C chemical shift assignments in natural and synthetic lignins. By appropriate choice of dimer and monomer, seven of the eight possible sequences of guaiacyl (G) and syringyl (S) units were prepared: GGG, GGS, GSG, GSS, SSS, SSG, and SGG. Preparaton of the missing sequence (SGS) by this method was not successful, so it was obtained by conventional synthetic techniques. Stereochemistry in the trimers was also controlled to some extent by utilizing dimers that were predominantly erythro (e) or threo (t), and by performing the oxidative coupling under conditions of high stereo-selectivity. The maximum number of geometric isomers in β-O-4 trimers is eight (one pair each of ee, et, te, tt). In this study the GGG and GGS trimers contained all eight isomers, the SGG trimer contained four isomers, and GSG, GSS, ...

We present the Tangerine Smart Micrel Cube (SMCube) a smart device for Human Computer Interaction (HCI). The SMCube is a tangible smart object equipped with sensors (digital tri-axes accelerom- eter as default) and actuators (infrared LEDs, vibro-motors) embedded in a wooden cube. Data from accelerometer is used to locally detect the active face (the one directed upward) and a set of gesture performed by the user. These information are wirelessly sent to a base station for processing. Furthermore, through the LEDs the node can interact with a vision based system in a multi modal activity detection scenario.

Forty-four patients suffering a stroke for the first time were examined within 10 h of the onset of symptoms; the tests performed on their admission to hospital, and thereafter on the third and seventh day, were 24-h Holter EKG with spectral analysis of heart rate variability, evaluation of arterial blood pressure and the levels of catecholamine in the blood and 24-h urine. The dynamic EKG on admission revealed that 31 (70.5%) out of the 44 patients already had arrhythmia. These alterations were observed in 9 (75%) out of 12 haemorrhagic patients with a significant (P < 0.05) prevalence compared to 22 (68.8%) of the 32 ischaemic ones. Arrhythmia showed up in 16 (76.2%) out of 21 cases with right hemisphere lesions and in 12 (63.2%) out of 19 cases of left hemisphere lesions; this difference was also significant (P

Dehydropolymerization of p-hydroxycinnamyl alcohols with manganese(III) acetate in either aqueous acetic acid or pyridine resulted in dehydropolymers (DHPs) that more closely approximate the structure of natural lignins than do DHPs produced by enzymic techniques. The 13C NMR spectrum of a “biomimetic” guaiacyl-DHP (G-DHP) from coniferyl alcohol was very similar to that of a lignin isolated from spruce wood, unlike a corresponding spectrum of a G-DHP prepared by a conventional enzymic technique. A similar comparison between a biomimetic guaiacyl/syringyl DHP (GS-DHP), a conventional GS-DHP, and a natural lignin from elm wood also confirmed a closer resemblance between the biomimetic DHP and the natural lignin. Likewise, a biomimetic S-DHP prepared from sinapyl alcohol was remarkably similar to a high syringyl fraction of lignin isolated from birch wood. The flexibility of the biomimetic approach is illustrated by the preparation of a DHP that is enriched in coniferaldehyde entities and one that i...

We performed Transcranial Doppler Monitoring to detect microembolic signals (MES) in 47 patients with moderate (30%–69%) carotid stenosis proven by selective angiography. We compared the occurence of MES with the clinical characteristics of stenosis (symptomatic or asymtpomatic) and the angiographic plaque features (nonulcerated, deep ulceration, superficial ulceration, ulceration with flap, or ulceration without flap). For these cases there was no indication for endarterectomy, nevertheless we thought it would be useful to identify risk subgroups that might benefit from surgical treatment. MES were detected in 17.9% of the stenoses with a prevalence (p < .01) in symptomatic cases (25%) compared to asymptomatic cases (14.3%). There was a significant correlation of MES with plaque ulceration (p < .01) and particularly with ulceration without flap (p < .01). No difference between deep and superficial ulceration was observed. The availability of prospective data on this topic might be useful to select subgroups of patients with moderate carotid stenosis at risk for embolism.

To determine whether clinical features can be used in a decision rule to prospectively identify a subgroup of internal jugular catheter placements that are correctly positioned and free from mechanical complications, thus obviating the need for routine postprocedural chest radiographs in selected patients.Prospective cohort study.Tertiary care teaching hospital.A total of 107 consecutive patients who presented to our catheter service for internal jugular catheter insertion because of clinical indications between November 1995 and April 1996. Exclusion criteria were mechanical ventilation, an altered mental status, an age of15 years, and a height of152 cm.Right or left internal jugular vein catheter placement followed by a postprocedural chest radiograph.The operating physician completed a detailed questionnaire for each catheter insertion, designed to detect potential complications and to predict the necessity, or lack of necessity, for a postprocedural chest radiograph. The questionnaire documented patient characteristics, the number of needle passes, difficulty establishing access, operator experience, poor anatomical landmarks, number of previous catheter placements, resistance to wire or catheter advancement, resistance to aspiration of blood or flushing of the catheter ports, sensations in the ear, chest, or arm, and development of signs or symptoms suggestive of pneumothorax. After catheter insertion, chest radiographs were obtained to assess for mechanical complications and malpositioned catheters.In 46 cases, the decision rule predicted either a complication or a malposition and, thus, the need for a chest radiograph. In 61 cases, neither was predicted (no chest radiograph was needed). Radiographs confirmed one complication (pneumothorax) and 15 catheter tip malpositions (nine in the right atrium and six in the right axillary vein). Among the 46 cases predicted to have a potential complication or malposition, there were one actual complication (pneumothorax) and six actual malpositions (three axillary vein malpositions and three right atrial malpositions). The positive predictive value of this decision rule is 15%. Among the 61 cases predicted to be free from complications or malpositions and not to require a postprocedural chest radiograph, there were nine unexpected malpositions (three axillary vein malpositions and six right atrial malpositions). The negative predictive value is 85%. The overall sensitivity of the decision rule for detecting complications and malpositions is 44%, and the specificity is 55%.In experienced hands, internal jugular venous catheterization is a safe procedure. However, the incidence of axillary vein or right atrial catheter malposition is 14%, and clinical factors alone will not reliably identify malpositioned catheters. Chest radiographs are necessary to ensure correct internal jugular catheter position.

When heated under anaerobic conditions, aqueous solutions of the polyoxometalate anion α-(SiVW 11 O 40 ] 5- (POM ox , 1), supplied as the salt K 5 [SiVW 11 O 40 ].12H 2 O, selectively delignify unbleached mixed-pine kraft pulps. During delignification, 1 is reduced hy residual lignin to α-[SiVW 11 O 40 ] 6- (POM red 2) : α-[SiVW 11 O 40 ] 5- + 1e- → α-[SiVW 11 O 40 ]6-, E o = +0.69V vs. NHE. Model studies suggest that phenolic (hydroxylated phenyl) groups present in residual lignin are substrates for the reduction of 1. Reactions of 1 with phenolic arylglycerol β-aryl ethers and other phenolic lignin models suggest that anaerobic POM degradation of residual lignin may occur via sequential single-electron oxidation reactions of phenolic substructures, first to cyclohexadienyl radicals and subsequently to cyclohexadienyl cations. Hydrolysis of these cationic intermediates results in alkyl-side-chain cleavage, a likely route to polymer degradation.

Summary Dehydrogenation polymers (DHPs) were prepared from coniferyl alcohol (CA), sinapyl alcohol (SA), and a mixture of coniferyl and sinapyl alcohol. The polymers were fully acetylated and their carbon NMR spectra were compared. Comparison of the 13C NMR spectra of the DHPs with those of authentic tri- and tetralignols facilitated the assignment of about 85% of the 117 reported signals. Most of the unassigned signals were those from syringyl units. Major differences between the DHP prepared from CA and a pine milled wood lignin were: a relative deficiency of s-O-4 linkages and a predominance of s-5, s-s, and CA end units in the DHP. In contrast, there was no significant quantity of SA end units in a DHP prepared from SA. A major conclusion of the study confirmed that DHPs prepared from CA are relatively poor models of natural lignins isolated from gymnosperms.

Typical solution-state 13C NMR spectra of lignins obtained with relatively modern instrumention contain well over 100 signals. The use of classical lignin model compounds is no longer sufficient for accurate interpretation of these spectra. Ultimately, the only valid models for etherified C9 units in lignin (which account for about 80% of the lignin polymer) must be at least trimeric or tetrameric, depending on the linkages involved. One approach that can be used involves NMR substituent effects. This approach avoids tedious syntheses while retaining the much-needed accuracy of chemical shift correlations between models and natural lignins. Appropriate substituent effects have been calculated by the use of an extensive NMR database of dimeric, trimeric and tetrameric lignin model compounds. Effects related to acetylation and solvent have also been determined. For example, accurate chemical shift data for an underivatized milled-wood lignin (MWL) in DMSO-d6 can be determined on the basis of the ch...

Summary Paris-Grignon, Lignin polymer model Dehydrogenation polymer The structures of novel lignin polymer models prepared from coniferin or coniferyl alcohol under conditions that approximate cell wal1 Signification were characterized by thioacidolysi s. The linkageof monolignol (DHP) type analysis by thioacidolysi s indicates that the structure of these polylignols approximated that of -. Monolignol glucoside native lignin more closely than did the structure of polylignols prepared by the conventional method Coniferyl ulcohol from coniferyl alcohol. Among v:arious possible factors affecting the structure of polylignols during Thioacidolysis polymerization under the present experimental conditions, the important ones appears to be: pH of the medium in which dehydrogenativc polymerization of coniferyl alcohol takes place; relative concentrations of monomer and oligomer radicals; and the carbohydrate matrix in which polymerization occurs.

Treatment of coniferyl alcohol with iron, cobalt, or manganese salts gave a variety of oligolignols and polylignols (DHPs). Conditions could be adjusted to favor high or low molecular weight products and to give different inter-unit linkage distributions. Oxidation with iron and manganese salts generally gave structures containing β-O-4, β-5, and β-β linkages. Oxidation with iron and manganese salts under highly alkaline conditions also generated α-O-4 structures. The cobalt salt K3Co(CN)6 was unique in that a novel β-γ linkage was generated in high yield. Reactions in the absence of solvent also resulted in the formation of oligolignols and DHPs.

Guaiacyl-type lignin polymer models were prepared from coniferin by the action of β-glucosidase and peroxidase, with hydrogen peroxide generated in situ through the action of oxygen and glucose oxidase on the glucose liberated from the coniferin. Polylignols were also prepared from coniferyl alcohol using procedures modified to more closely correspond to conditions prevailing in the cell wall environment. The structure of these novel polylignols approximated that of native lignin more closely than did the structure of polylignols prepared by the conventional method from coniferyl alcohol.

The lignin peroxidases (LiPs) of white-rot basidiomycetes are generally thought to catalyze the oxidative cleavage of polymeric lignin in vivo. However, direct evidence for such a role has been lacking. In this investigation, 14C- and 13C-labeled synthetic lignins were oxidized with a purified isozyme of Phanerochaete chrysosporium LiP. Gel permeation chromatography of the radiolabeled polymers showed that LiP catalyzed their cleavage to give soluble lower-M(r) products. To a lesser extent, the enzyme also polymerized the lignins to give soluble higher-M(r) products. This result is attributable to the fact that purified LiP, unlike the intact fungus, provides no mechanism for the removal of lignin fragments that are susceptible to repolymerization. LiP catalysis also gave small quantities of insoluble, perhaps polymerized, lignin, but in lower yield than intact P. chrysosporium does. 13C NMR experiments with 13C-labeled polymer showed that LiP cleaved it between C alpha and C beta of the propyl side chain to give benzylic aldehydes at C alpha, in agreement with the cleavage mechanism hypothesized earlier. The data show that LiP catalysis accounts adequately for the initial steps of ligninolysis by P. chrysosporium in vivo.

Objective: Fasting insulin concentrations are often used as a surrogate measure of insulin resistance. We investigated the relative contributions of fasting insulin and insulin resistance to cardiometabolic risk and preclinical atherosclerosis. Design and methods: The Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) cohort consists of 1326 European non-diabetic, overall healthy men and women aged 30-60 years. We performed standard oral glucose tolerance tests and hyperinsulinemic euglycemic clamps. As a general measure of cardiovascular risk, we assessed the prevalence of the metabolic syndrome in 1177 participants. Carotid artery intima media thickness (IMT) was measured by ultrasound to assess preclinical atherosclerosis. Results: Fasting insulin was correlated with all elements of the metabolic syndrome. Insulin sensitivity (M/I) was correlated with most elements. The odds ratio for the metabolic syndrome of those in the highest quartile of fasting insulin compared with those in the lower quartiles was 5.4 (95% confidence interval (CI) 2.8-10.3, adjusted for insulin sensitivity) in men and 5.1 (2.6-9.9) in women. The odds ratio for metabolic syndrome of those with insulin sensitivity in the lowest quartile of the cohort compared with those in the higher quartiles was 2.4 (95% CI 1.3-4.7, adjusted for fasting insulin) in men and 1.6 (0.8-3.1) in women. Carotid IMT was only statistically significantly associated with fasting insulin in both men and women. Conclusions: Fasting insulin, a simple and practical measure, may be a stronger and independent contributor to cardiometabolic risk and atherosclerosis in a healthy population than hyperinsulinemic euglycemic clamp-derived insulin sensitivity. © 2009 European Society of Endocrinology.

The continuing evolution of nuclear magnetic reso­ nance (NMR) spectroscopy has resulted in hundreds of new experiments and techniques in the past few years. Many of these are now routine and can be im­ plemented on most modern spectrometers. However, few of these techniques have been applied to the characterization of lignin structure. Consequently, no comparisons between the various techniques or prac­ tical guidelines as to their implementation, as applied to lignin, have been published. This report describes the implementation of several useful techniques to facilitate interpretation of 13C NMR spectra of lignins.

Determination of the optimal methods for enhancing the resolution of lignin spectra, of the limiting aspects of field strength on signal dispersion and resolution, and of the optimal signal resolution that may be expected under various conditions.

Fertility is usually restored in women after solid organ transplantation, and successful pregnancies have been reported in female recipients of kidney, liver, heart, pancreas-liver, and lung transplants. However, women with solid organ allografts have higher incidence of pregnancy complications like hypertension, preeclampsia, preterm delivery. Hypertension appears to be dependent on the type of immunosuppressive agents. The influence of pregnancy on the risk of rejection is poorly known on the basis of available data. Rejection rate appears to be at least similar to the nonpregnant population. In some cases, such as in liver transplant pregnant women, even higher as compared to the nonpregnant population. Maintaining appropriate blood levels of immunosuppressive drugs is currently recommended. Malformation rate in the offsprings of transplanted women appears to not be increased; long-term follow- up of children born to allograft recipients is necessary to investigate possible developmental, immunological, or oncological disorders. We followed 70 pregnancies after kidney transplantation and nine after liver transplantation. All recipients were maintained on immunosuppressive therapy during pregnancy, except one mother who refused immunosuppression and experienced transplant rejection. Hypertension was the most frequent complication during pregnancy: in 23% of kidney transplantated mothers and in one out of nine liver transplant recipients. The only malformation observed in the newborns was the dislocation of the hip in the child of a kidney transplant recipient.

Objectives: To assess the ability of selective bronchography to predict which patients with neoplastic postobstructive atelectasis will respond to interventional therapies directed at the reexpansion of the affected lung. Furthermore, to compare the utility of selective bronchography with the current predictive standard that reversal of postobstructive atelectasis is unlikely when it is > 4 weeks in duration (ie, the 4-week rule). Design: A prospective observational study. Setting: A tertiary care referral center/medical school. Patients: Twenty-seven consecutive patients with advanced lung cancer or other malignancy, with documented neoplastic postobstructive atelectasis involving a total of 44 lobes. Interventions: Lobar collapse was documented radiographically. The duration of atelectasis was investigated and quantified as accurately as possible. Prior to the use of interventional therapies, selective bronchography was performed on each collapsed lobe, and the results were documented. Bronchography results did not influence the decision to proceed with interventional therapies. Patients had each of their collapsed lobes manipulated by interventional techniques that were directed at reexpansion of the lung. One week after the patient underwent the intervention, the degree of reexpansion was assessed radiographically. Results: Interventional therapies leading to significant reversal of airway narrowing were completed in all 44 lobes. These were successful in reexpanding 28 of 44 collapsed lobes (64%). Selective bronchography demonstrated the following two distinct patterns: an intact bronchial tree (ie, tree pattern); or the absence of a distinguishable, distal bronchial tree (ie, blush pattern). The sensitivity of selective bronchography to predict reexpansion is 1.00 (95% confidence interval [CI], 0.90 to 1.00), and its specificity is 0.56 (95% CI, 0.30 to 0.80). There were no complications attributable to selective bronchography. The sensitivity of the 4-week rule to predict reexpansion is 0.61 (95% CI, 0.41 to 0.78), and its specificity is 0.75 (95% CI, 0.48 to 0.93). The results of selective bronchography and use of the 4-week rule were significantly different in predicting which lobes would reexpand and which would not (p 0.0026). Using selective bronchography to predict the reversal of lobar atelectasis, the positive predictive value of the tree pattern was 0.80 and the negative predictive value of the blush pattern was 1.00. The values for the 4-week rule are 0.81 and 0.52, respectively. Conclusions: Selective bronchography is a useful tool for predicting whether patients with neoplastic postobstructive atelectasis would benefit from interventional techniques that are directed at lobar reexpansion. Selective bronchography appears to be superior to the 4-week rule in this regard. (CHEST 2003; 123:828–834)

In asymptomatic prosthetic valve recipients, high-intensity transient signals (HITS) observed with transcranial Doppler (TCD) are a phenomenon of obscure clinical relevance which nature has not yet been elucidated convincingly.Eighty-three patients without carotid disease, history of cerebrovascular accidents, and with negative preoperative TCD undergoing either valve replacement (mitral, n = 11; aortic, n = 56; mitral + aortic, n = 6; 40 mechanical prostheses, 29 biological prostheses, 10 homografts) or mitral repair (n = 10) were evaluated prospectively by means of TCD at discharge, three months and one year after surgery, to analyze the presence, incidence and characteristics of HITS. Furthermore, in 12 patients positive for HITS, TCD was repeated during a 30-min period of 100% O2 inhalation.Twenty-five patients (30%) were positive for HITS at all postoperative controls, although no neurological symptoms were observed. Mechanical prostheses showed a significantly higher incidence of HITS (85%) than biological prostheses (10%, p0.001), repaired mitral valves (0%, p0.001) and homografts (0%, p0.001). At multivariate analysis the presence of a mechanical prosthesis was the only significant predictor of detection of HITS after valve replacement. During O2 inhalation, a significant decrease in the number of HITS per hour (55 +/- 79 versus 22 +/- 31, p = 0.002) occurred, which returned to initial values when room-air breathing was resumed.Prosthetic valve replacement, particularly when mechanical devices are used, is associated with the generation of HITS which persist throughout the follow up period, but remain clinically silent. The decrease of HITS during O2 inhalation strongly supports the hypothesis of the gaseous nature of such signals and confirms the validity of this method in helping to differentiate gaseous microemboli from solid microemboli in prosthetic valve recipients.

An unusual acute hypotensive syndrome has been observed in association with administration of trimethoprim-sulfamethoxazole (TMP-SMZ) to patients with human immunodeficiency virus (HIV) infection. In the 11 cases that have been reported, the syndrome differs from classic anaphylaxis and resembles septic shock. Mediation by tumor necrosis factor (TNF) has been hypothesized, but the mechanism has not been characterized with cytokine assays, and no invasive hemodynamic measurements have been reported. We describe a case of recurrent hyperdynamic shock--without classic features of anaphylaxis, without detectable IgE antibodies against TMP or SMZ, and without detectable levels of TNF--involving an HIV-infected patient rechallenged with TMP-SMZ.

The lignin peroxidases (LiPs) of white-rot basidiomycetes are generally thought to catalyze the oxidative cleavage of polymeric lignin in vivo. However, direct evidence for such a role has been lacking. In this investigation, 14C- and 13C-labeled synthetic lignins were oxidized with a purified isozyme of Phanerochaete chrysosporium LiP. Gel permeation chromatography of the radiolabeled polymers showed that LiP catalyzed their cleavage to give soluble lower-M(r) products. To a lesser extent, the enzyme also polymerized the lignins to give soluble higher-M(r) products. This result is attributable to the fact that purified LiP, unlike the intact fungus, provides no mechanism for the removal of lignin fragments that are susceptible to repolymerization. LiP catalysis also gave small quantities of insoluble, perhaps polymerized, lignin, but in lower yield than intact P. chrysosporium does. 13C NMR experiments with 13C-labeled polymer showed that LiP cleaved it between C alpha and C beta of the propyl side chain to give benzylic aldehydes at C alpha, in agreement with the cleavage mechanism hypothesized earlier. The data show that LiP catalysis accounts adequately for the initial steps of ligninolysis by P. chrysosporium in vivo.

Hyperinflation is usually related to the clinical stages of chronic obstructive lung disease (COLD) and it specifically characterizes these patients.1

Threo and erythro isomers of 3-acetoxy-1-(4-acetoxy-3-methoxyphenyl) -1- (9,10-dihydro-10-hydroxy-9-oxoanthracen-10-yl) -2-(2-tnethoxyphenoxy)-propane 8 have been synthesized. These compounds are appropriate model compounds for adducts between anthranol (9-hydroxyanthracene) and quinone raethides of β-aryl ether units in the lignin polymer. Adducts of this type are believed to result from side reactions during the anthraquinone-accelerated pulping of wood and may contribute to extensive losses of anthraquinone from the pulping system. The 13C NMR chemical shift3 of C-10 in the threo and erythro isomers of β are 44.1 and 47.5 ppm relative to tetramethylsilane. Peaks with corresponding chemical shifts appeared in a spectrum of an acetylated adduct prepared from lignin and 9,10- 3C labelled anthranol. As in model systems the threo isomer predominated.

Interpretation des spectres 13 C et 1 H du neoabietate de methyle, derive d'acide triterpenique

Synthesis of 14 C Labeled 3-Methoxy-4-Hydroxy-�. -(2-Methoxyphenoxy)-�� -Hydroxypropiophenone. Lignin Models a Lignin Model Compound Synthesis Labeled Models Summary Lignin Biodegradation Modification of literature methods improved the synthesis of 3-methoxy-4-hydroxy-α-(2-methoxy- phenoxy)-β-hydroxypropiophenone (10). The new procedures were developed to adapt the synthesis to small-scale operations, permitting 14 C-labeling. A simple vacuum filtration apparatus was devised to minimize transfers and reduce losses. Described here is the preparation, from (Ring-U-14C)-phenol, of structure (10) labeled uniformly in the propiophenone ring; the overall yield in the ten-step sequence was approximately 9%. The method as described can be used to label either ring, or to introduce spe- cific labels in the methoxyl or propyl carbons. Literature methods can also be used to label specific ring carbons in starting materials. Schlusselworter Synthese von 14 C-markiertem 3-Methoxy-4-hydroxy-α-(2-methoxyphenoxy)-β-hydroxypropiophenon, (Sachgebiete) einer Ligninmodellsubstanz Lignin-Modellsubstanzen Zusammenfassung (Synthese) 14 C-Ring-Markierung In der Literatur beschriebene Methoden zur Synthese von 3-Methoxy-4-hydroxy-α-(2-methoxyphen- Ligninabbau durch oxy)-β-hydroxypropiophenon (10) wurden verbessert. Sie wurden weiter fur die 14 C-Markierung in Mikroorganismen � kleinem Masstab modifiziert. In diesem Zusammenhang wurde ein einfacher Apparat zur Filtrierung im Vakuum entwickelt, der Uberfuhrungs- und Filtrierungsverluste stark vermindert. In der vorliegen- den Arbeit wird im besonderen die Herstellung von im phenolischen Kern gleichmasig 14 C-markiertem (10) aus ebenso markiertem 14 C-Phenol beschrieben; die Gesamtausbeute der 10-stufigen Synthese betragt etwa 9%. Die angegebene Methode kann sowohl zur unspezifischen Markierung im phenolischen Kern als auch zur spezifischen Markierung am Methoxylkohlenstoff oder an der Propylseitenkette herangezogen werden. Durch Anwendung von in der Literatur beschriebenen Methoden ist auch eine spezifische 14 C-Ring-Markierung in den Ausgangsmaterialien erzielbar.

(m, 2 H), 3.55-3.98 (m, 1 H), 3.03 (br s, 1 H), 1.15-2.25 (m, 6 H); mass spectrum (70 eV), m/e 141; exact mass calcd for C7HllN02 141.0790, found 141.0790. cis-2-(Hydroxyacetyl)cyclopentanol (34): mp 62-64 “C; IR (Nujol) 3600-3050, 1710 cm-’; NMR (CDC13, 300 MHz) 6 4.50-4.60 (m, 1 H), 4.35 (AB q, 2 H, J = 19 Hz), 3.12 (br s, 1 H), 2.82 (dt, 1 H, J = 9.5,4.85 Hz), 2.51 (br s, 1 H), 1.60-2.15 (m, 6 H); mass spectrum (70 eV), m/e 144, 126; exact mass calcd for C7H1,,02 (C,H1203 H20) 126.0681, found 126.0681. cis -2-Hydroxycyclopentanecarboxylic acid (35): mp 53 “C (lit.m mp 52-53.4 “C); IR (melt) 3600-2400,1720 cm-’; NMR (CDC13/D,0, 90 MHz) 6 4.33-4.63 (m, 1 H), 2.60-3.00 (m, 1 H), 1.60-2.15 (m, 6 H); mass spectrum (70 eV), m/e 130, 112; exact mass calcd for CsH8O2 (C6HlOO3 HzO) 112.0524, found 112.0524.

Summary The authors have studied the sleep of 6 hydrocephalic infants. In 4 cases disturbed sleep was noticed, characterized by insomnia in 2 cases, and frequent interruptions of sleep in the other 2 cases. In the last cases no other particular alterations were observed. The research was continued in 2 cases, operated on with the Pudenz Valve. In one of which the valve functioned well, sleep was restructured. In the second case the valve did not function well and sleep was not restructured. This suggests the hypothesis that the endocranial hypertension may alter the sleep cycles.

The quinone methide from guaiacylglycol-β-guaiacyl ether [l-(3-methoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)ethanol] formed carbon-carbon bonded adducts with both anthrone and anthrahydroquinone (AHQ). It was found that the anthrone adduct [l-(3-methoxy-4-hydroxyphenyl)-1-(anthracen-9-one-10-yl)-2-(2-methoxyphenoxy)ethane] was much more resistant to alkaline degradation than the corresponding AHQ-adduct Jl-(3-methoxy-4-hydroxyphenyl)-l-(10-hydroxyanthracen-9-one-10-yl)-2-(2-methoxyphenoxy)ethane]. It was demonstrated, by NMR spectroscopy that analogous anthrone and AHQ adducts formed with milled wood lignin and had relative alkaline stabilities consistent with those observed with the model adducts. At 10° C the AHQ-lignin adduct partially decomposed to the Y-monoacetates of coniferyl alcohol and p_-coumaryl alcohol which subsequently reacted with excess AHQ to give the novel adducts, trans-1-(3-methoxy-4-hydroxyphenyl)-3-(10-hydroxyanthracen-9-one-10-yl)propene, and trans-1-(4-hydroxyphenyl)-3-(1...

Spent liquor fractions from soda and soda/anthraquinone cooks of loblolly pine wood meal were examined by C-13 NMR spectroscopy. The material which precipitated from the liquors at pH 7 as well as that remaining in solution were acetylated and fractionated on a styrene-divinylbenzene gel column. This technique was an attempt to simplify spectral interpretation and to elucidate the distribution of anthracenyl structures within the spent liquor components. The NMR spectra of fractions of the precipitated material revealed that anthracenyl structures chemically bound to lignin increased with decreasing molecular weight (MW), whereas, polysaccharide content decreased markedly with decreasing MW. The NMR spectra of the soluble material had no anthracenyl peaks, but did contain a significant peak at 105 ppm. This is in the same location as a predominant peak observed in C-13 NMR spectra of hardwood lignins, and which has been assigned to C2 and C6 of syringyl structures. However, in the present study t...

Extensive loss of anthraquinone (AQ) or the active catalyst anthrahydroquinone (AHQ) from the AQ –- AHQ catalytic cycle has been explained in part by side reactions leading to the reaction product anthrone (anthracen-9-one), followed by subsequent formation of adducts with lignin quinone methides. Degradation of an adduct between anthrone and the quinone methide of guaiacylglycerol-β-guaiacyl ether, under soda pulping conditions, resulted in a complex mixture of products. The mixture included 3-guaiacylbenzanthrone, bianthronyl, bianthrone, guaiacol, AQ, trans-coniferyl alcohol, trans-coniferylaldehyde, cis- and trans-1-(3-methoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)ethene, vanillin, and 2-methoxy-4-vinylphenol. C-13 NMR studies of lignins isolated from soda/AQ spent liquors indicated the presence of residual anthrone adducts and a significant content of chemically attached AQ.

The number average structure and the molecular weight distribution of phenol-formaldehyde prepolymers for use in synthesis of tannin-based adhesive resins were determined with 1H- and 13C-NMR spectroscopy and gel permeation chromatography of acetylated resins. These methods were used to determine differences in phenol-formaldehyde prepolymens prepared under different reaction conditions. Quantitative 13C-NMR techniques provided a detailed analysis of the structure of a phenol-formaldehyde prepolymer.