From lignocellulose to plastics: Knowledge transfer on the degradation approaches by fungi.

In this review, we argue that there is much to be learned by transferring knowledge from research on lignocellulose degradation to that on plastic. Plastic waste accumulates in the environment to hazardous levels, because it is inherently recalcitrant to biological degradation. Plants evolved lignocellulose to be resistant to degradation, but with time, fungi became capable of utilising it for their nutrition. Examples of how fungal strategies to degrade lignocellulose could be insightful for plastic degradation include how fungi overcome the hydrophobicity of lignin (e.g. production of hydrophobins) and crystallinity of cellulose (e.g. oxidative approaches). In parallel, knowledge of the methods for understanding lignocellulose degradation could be insightful such as advanced microscopy, genomic and post-genomic approaches (e.g. gene expression analysis). The known limitations of biological lignocellulose degradation, such as the necessity for physiochemical pretreatments for biofuel production, can be predictive of potential restrictions of biological plastic degradation. Taking lessons from lignocellulose degradation for plastic degradation is also important for biosafety as engineered plastic-degrading fungi could also have increased plant biomass degrading capabilities. Even though plastics are significantly different from lignocellulose because they lack hydrolysable C-C or C-O bonds and therefore have higher recalcitrance, there are apparent similarities, e.g. both types of compounds are mixtures of hydrophobic polymers with amorphous and crystalline regions, and both require hydrolases and oxidoreductases for their degradation. Thus, many lessons could be learned from fungal lignocellulose degradation.

H-D exchange in deuterated trifluoroacetic acid via ligand-directed NHC-palladium catalysis: a powerful method for deuteration of aromatic ketones, amides, and amino acids.

A method has been developed for one-step ortho-selective ligand-directed H-D exchange, accompanied in some cases by concurrent acid-catalyzed electrophilic deuteration. This method is effective for deuteration of aromatic substrates ranging from ketones to amides and amino acids, including compounds of biological and pharmaceutical interest such as acetaminophen and edaravone. Use of a palladium catalyst featuring an NHC ligand is critical for the observed reactivity. Experimental evidence strongly suggests that palladium facilitates C-H activation of the aromatic substrates, a mechanism seldom observed under strongly acidic conditions. 2015 Elsevier Ltd. All rights reserved.

Dyspepsia in the community: value of a community-based mailed survey to identify potential participants for a randomized clinical trial.

OBJECTIVE: To assess the usefulness of a community-based mailed survey to identify participants with functional dyspepsia (FD) for a clinical trial. MATERIAL AND METHODS: In 2008, a valid self-report questionnaire of gastrointestinal symptoms required for diagnosis of FD was mailed to randomly selected cohorts of Olmsted County, Minnesota, residents. From survey responses (54%), FD cases and controls were identified. Phone calls were completed in 2010 and 2011 to 54% of respondents offering participation to those meeting criteria. RESULTS: Of 937 people identified from the survey, 189 cases and 265 controls were contacted by phone using four questions similar to the written survey resulting in a moderate level of agreement (Kappa 0.43, 95% CI: 0.35- 0.51; p = 0.11). The proportion reporting FD symptoms by survey was 42%, while the proportion by phone was 38%. Comparing classification of cases and controls, 118 (62%) survey cases had dyspepsia symptoms on phone screening while 53 (20%) of the survey controls reported FD symptoms. Of 171 who had symptoms, 60 (35%) declined, 33 (19%) were over study age limit, 24 (14%) had inadequate symptom levels and 36 (21%) had comorbidities. Of survey respondents contacted, six (3%) people were enrolled with two screen fails resulting in four (1%) randomized. CONCLUSION: Agreement between survey and phone questions was modest. Classifications between case and control changed. People eligible and willing to participate were a fraction of people reporting symptoms. People participating in clinical trials do not broadly represent those in the population.

Hydrogen-deuterium exchange of aromatic amines and amides using deuterated trifluoroacetic acid.

The H-D exchange of aromatic amines and amides, including pharmaceutically relevant compounds such as acetaminophen and diclofenac, was investigated using CF3COOD as both the sole reaction solvent and source of deuterium label. The described method is amenable to efficient deuterium incorporation for a wide variety of substrates possessing both electron-donating and electron-withdrawing substituents. Best results were seen with less basic anilines and highly activated acetanilides, reflecting the likelihood of different mechanistic pathways.

Dual Studies on a Hydrogen-Deuterium Exchange of Resorcinol and the Subsequent Kinetic Isotope Effect.

An efficient laboratory experiment has been developed for undergraduate students to conduct hydrogen-deuterium (H-D) exchange of resorcinol by electrophilic aromatic substitution using D2O and a catalytic amount of H2SO4. The resulting labeled product is characterized by 1H NMR. Students also visualize a significant kinetic isotope effect (kH/kD ≈ 3 to 4) by adding iodine tincture to solutions of unlabeled resorcinol and the H-D exchange product. This method is highly adaptable to fit a target audience and has been successfully implemented in a pedagogical capacity with second-year introductory organic chemistry students as part of their laboratory curriculum. It was also adapted for students at the advanced high school level.

Chemoselective hydroamination of vinyl arenes catalyzed by an NHC-amidate-alkoxide Pd(II) complex and p-TsOH.

The hydroamination of various substituted vinyl arenes with benzenesulfonamide was explored using an NHC-amidate-alkoxide palladium catalyst in conjunction with p-TsOH. Utilizing halide-substituted and electron-rich vinyl arenes, this methodology selectively furnished the cross-coupled hydroamination products in moderate to excellent yields in a Markovnikov fashion while greatly reducing undesired acid-catalyzed homocoupling of the vinyl arenes. Electron-rich vinyl arenes typically required milder conditions than electron-poor ones. While most effective for para-substituted substrates, the catalyst system also furnished the desired products from ortho- and meta-substituted vinyl arenes with high chemoselectivities.

Two-stage fungal biopulping for improved enzymatic hydrolysis of wood.

A novel two-stage, whole organism fungal biopulping method was examined for increasing the yield of enzymatic hydrolysis of wood into soluble glucose. Liriodendron tulipifera wood chips (1g) were exposed to liquid culture suspensions of white rot (Ceriporiopsis subvermispora) or brown rot (Postia placenta) fungi and incubated at 28°C, either alone in single-stage 30 day (one fungal species applied) or two-stage 60 day (both fungal species applied in alternative succession) treatments. Fungi grew in all treatments, but did not significantly decrease the percent carbohydrate content of the wood. Two-stage treatments differed significantly in mass loss depending on order of exposure, suggesting additive or inhibitory fungal interactions occurred. Treatments consisting of C. subvermispora followed by P. placenta exhibited 6 ± 0.5% mass loss and increased the yield of enzymatic hydrolysis by 67-119%. This significant hydrolysis improvement suggests that fungal biopulping technologies could support commercial lignocellulosic ethanol production efforts if further developed.

Irritable bowel syndrome and chronic pelvic pain: a population-based study.

BACKGROUND: Women with irritable bowel syndrome (IBS) frequently report chronic pelvic pain, however, it is still unanswered whether these are truly separate entities. IBS negatively impacts on quality of life, but the impact of IBS on sexual function is not clear. GOALS: We aimed to (1) describe the impact of IBS on sexual function, and (2) evaluate the association between pelvic pain and IBS, and in particular identify if there are unique characteristics of the overlap group. STUDY: The Talley Bowel Disease Questionnaire was mailed to an age- and gender-stratified random sample of 1031 Olmsted County, Minnesota residents aged 30 to 64 years. Manning (at least 2 of 6 positive) and Rome criteria (Rome I and modified Rome III) were used to identify IBS. Pelvic pain was assessed by a single item. Somatization was assessed by the valid somatic symptom checklist. RESULTS: Overall 648 (69%) of 935 eligible participants responded (mean age 52 years, 52% female). Self-reported sexual dysfunction was rare (0.9%; 95% CI 0.3-2.0%). Among women, 20% (95% CI 16-24%) reported pain in the pelvic region; 40% of those with pelvic pain met IBS by Manning, or Rome criteria. IBS and pelvic pain occurred together more commonly than expected by chance (P<0.01). The overall somatization score (and specifically the depression and dizziness item scores) predicted IBS-pelvic pain overlap versus either IBS alone or pelvic pain alone. CONCLUSION: In a subset with pelvic pain, there is likely to be a common underlying psychologic process (somatization) that explains the link to IBS.

Asymmetric intermolecular boron Heck-type reactions via oxidative palladium(II) catalysis with chiral tridentate NHC-amidate-alkoxide ligands.

Chiral dimeric tridentate NHC-amidate-alkoxide palladium(II) complexes, 3a and 3b, effected oxidative boron Heck-type reactions of aryl boronic acids with both acyclic and cyclic alkenes at room temperature to afford the corresponding coupling products with high enantioselectivities. The high degree of enantioselection, far superior to existing methods, stems from differences in the nonbonding interactions in the proposed transition states, due to the influence from bulky substituents of the alkene substrates and the "counter axial groups" of the palladium(II) catalysts.