Ultrastructure of the Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) midgut

The insect midgut has ultimately been the focus of researches tempting to control insect pests because alterations in the insect gut may affect not only its development, but also physiological events such as nutrient absorption and transformation. The objective of the present work was to describe morphologically, histochemically, and ultrastructurally the larva midgut of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), a cotton key pest in Brazil. Light and electronic transmission microscopy was used to obtain images from midgut sections of late fourth-instar larvae of A. argillacea. In general, the morphology, histochemistry, and ultrastructure characteristics of A. argillacea midgut follow that described in the literature for other lepidopteran species. However, the results showed a mitochondrial polymorphism and branched microvilli, which suggest an ultrastrucutural and physiological modification possibly associated with a high absorption and secretion activity by the columnar cells of this species. This intense activity may favor a faster response related to the action of ingested microbial agents and/or toxins, and can explain the high susceptibility of A. argillacea to the agents of control such as the toxin of Bacillus thuringiensis.     

Ion mobility-mass correlation trend line separation of glycoprotein digests without deglycosylation

A high-throughput ion mobility mass spectrometer (IMMS) was used to rapidly separate and analyze peptides and glycopeptides derived from glycoproteins. Two glycoproteins, human α-1-acid glycoprotein and antithrombin III were digested with trypsin and subjected to electro-spray traveling wave IMMS analysis. No deglycosylation steps were performed; samples were complex mixtures of peptides and glycopeptides. Peptides and glycosylated peptides with different charge states (up to 4 charges) were observed and fell on distinguishable trend lines in 2-D IMMS spectra in both positive and negative modes. The trend line separation patterns matched between both modes. Peptide sequence was identified based on the corresponding extracted mass spectra and collision induced dissociation (CID) experiments were performed for selected compounds to prove class identification. The signal-to-noise ratio of the glycopeptides was increased dramatically with ion mobility trend line separation compared to non-trend line separation, primarily due to selection of precursor ion subsets within specific mobility windows. In addition, isomeric mobility peaks were detected for specific glycopeptides. IMMS demonstrated unique capabilities and advantages for investigating and separating glycoprotein digests in this study and suggests a novel strategy for rapid glycoproteomics studies in the future.     

Synthesis and inclusion properties of pillar[n]arenes

A detailed study of the reaction conditions revealed that a quantitative cyclocondensation of 1,4-dialkoxy-2,5-bis(alkoxymethyl)-benzenes to pillar[n]arenes can be achieved by catalysis of p-toluenesulfonic acid in CH₂Cl₂. Major product of this new reaction is in each case a cyclopentamer (n = 5), but small amounts of the pillar[n]arenes with n = 6, 7 and 10 can be obtained as well. Different alkoxy groups in 1- and 4-position lead to regioisomers. All cyclooligomers exist in pillar structures as pair of enantiomers, which show a racemisation at room temperature, which is fast in terms of the NMR time scale. The racemisation process occurs by rotation of the 1,4-phenylene segments in the macrocyclic rings. Pillar[n]arenes exhibit novel host–guest behavior.     

SO2–ethanol–water (SEW) fractionation process: production of dissolving pulp from spruce

SO₂–ethanol–water (SEW) fractionation process is a highly attractive platform for future lignocellulosic Biorefineries. Its governing advantages include high flexibility in the selection of the raw material, simple and efficient recovery of fractionation chemicals, absence of carbohydrate degradation (both cellulose and hemicelluloses), and high reaction rates. The process is suitable for production of various carbohydrate- and lignin-based products including papermaking pulp, glucose, bioalcohols and lignosulfonates. The present paper addresses the possibility of producing dissolving pulp from spruce using SEW fractionation followed by ECF bleaching with and without hot caustic extraction. Comprehensive characterisation of chemical and macromolecular properties of the SEW dissolving pulps was complemented by determining the quality of viscose. The comparison with conventional viscose-grade acid sulfite pulps revealed close proximity in all properties. Therefore, considering the advantages of SEW process, it is suggested as a possible replacement for acid sulfite process in dissolving pulp manufacturing.     

Cycloaddition reactions of 2H-benzo[b]thiete and conjugated cyclic dienes

2H-Benzo[b]thiete 1 reacts with cyclopentadiene 3 in consecutive [8π + 2π]cycloadditions yielding the condensed heterocycles 6–8 . Tetracyclone 9 on the other hand gives only the monoadduct 10 . An [8π + 8π]cycloaddition can be observed for 1 and diphenylisobenzofuran 11 . The related π system 13 shows again consecutive [477π + 27π]processes ( 1 + 13 ← 14, 15 ).     

Polymer membranes in medicine

Mass transfer within the human body primarily occurs across biological membranes. Medicine mimics nature and uses synthetic membranes for therapeutic purposes. The state of the art of polymer membrane applications in medicine is reviewed. The target for membrane material developments is mainly the improvement of the patients' safety and convenience. To provide optimal blood compatibility a new biocompatible polymer for hemodialysis membranes has been developed in our group: a polycarbonate with polyether blocks. The copolymer is suitable for production of membranes with excellent performance. In addition to therapeutic purposes polymer membranes can provide diagnostic functions. Recently a blood glucose test strip based on a synthetic membrane has been developed. The membrane separates off the erythrocytes and contains enzymes and reagents. It enables the diabetic a precise and convenient measurement.     

Selective reductions. 56. Exploration of the B-haloisopinocampheylboranes for asymmetric reduction of ketones

A series of diisopinocampheylhaloboranes and monoisopinocampheyldihaloboranes were synthesized by the reaction of the corresponding boranes with the respective HX or X₂ (X = halogen) or by the hydroboration of α-pinene with the corresponding haloboranes. Stabilities of these haloboranes in various solvents were studied. Most of these haloboranes proved capable of reducing prochiral ketones to the alcohols with significant optical induction. When tested against a representative aromatic and aliphatic prochiral ketone, acetophenone and 3-methyl-2-butanone, respectively, α-phenethyl alcohol in 65–98% ee and 3-methyl-2-butanol in 28–59% ee were obtained. Some of them exhibited anomalous behavior.