Development of an epi-fluorescence assay for monitoring yeast viability and pretreatment hydrolysate toxicity in the presence of lignocellulosic solids

Applied Biochemistry and Biotechnology -     

The wrinkle and its measurement--a skin surface Profilometric method

This study outlines a simple 'Profilometric' method for measuring the size and function of the wrinkles. Wrinkle size was measured in relaxed conditions and the representative parameters were considered to be the mean 'Wrinkle Depth', the mean 'Wrinkle Area', the mean 'Wrinkle Volume', and the mean 'Wrinkle Tissue Reservoir Volume' (WTRV). These parameters were measured in the wrinkle profiles under relaxed conditions. The mean 'Wrinkle to Wrinkle Distance', which measures the distance between two adjacent wrinkles, is an accurate indicator of the muscle relaxation level during replication. This parameter, identified as the 'Muscle Relaxation Level Marker', and its reduction are related to increased muscle tone or contraction and vice versa. The mean Wrinkle to Wrinkle Distance is very important in experiments where the effectiveness of an anti-wrinkle preparation is tested. Thus, the correlative wrinkles' replicas, taken during follow up in different periods, are only those that show the same mean Wrinkle to Wrinkle Distance. The wrinkles' functions were revealed by studying the morphological changes of the wrinkles and their behavior during relaxed conditions, under slight increase of muscle tone and under maximum wrinkling. Facial wrinkles are not a single groove, but comprise an anatomical and functional unit (the 'Wrinkle Unit') along with the surrounding skin. This Wrinkle Unit participates in the functions of a central neuro-muscular system of the face responsible for protection, expression, and communication. Thus, the Wrinkle Unit, the superficial musculoaponeurotic system (superficial fascia of the face), the underlying muscles controlled by the CNS and Psyche, are considered to be a 'Functional Psycho-Neuro-Muscular System of the Face for Protection, Expression and Communication'. The three major functions of this system exerted in the central part of the face and around the eyes are: (1) to open and close the orifices (eyes, nose, and mouth), contributing to their functions; (2) to protect the eyes from sun, foreign bodies, etc.; (3) to contribute to facial expression, reflecting emotions (real, pretended, or theatrical) during social communication. These functions are exercised immediately and easily, without any opposition ('Wrinkling Ability') because of the presence of the Wrinkle Unit that gives (a) the site of refolding (the wrinkle is a waiting fold, ready to respond quickly at any moment for any skin mobility need) and (b) the appropriate skin tissue for extension or compression (this reservoir of tissue is measured by the parameter of WTRV). The Wrinkling Ability of a skin area is linked to the wrinkle's functions and can be measured by the parameter of 'Skin Tissue Volume Compressed around the Wrinkle' in mm(3) per 30 mm wrinkle during maximum wrinkling. The presence of wrinkles is a sign that the skin's 'Recovery Ability' has declined progressively with age. The skin's Recovery Ability is linked to undesirable cosmetic effects of ageing and wrinkling. This new Profilometric method can be applied in studies where the effectiveness of anti-wrinkle preparations or the cosmetic results of surgery modalities are tested, as well as in studies focused on the functional physiology of the Wrinkle Unit.     

Redox chemistry and H-atom abstraction reactivity of a terminal zirconium(iv) oxo compound mediated by an appended cobalt(i) center

The reactivity of the terminal zirconium(iv) oxo complex, O Zr(MesNPⁱPr₂)₃CoCN^tBu (2), is explored, revealing unique redox activity imparted by the pendent redox active cobalt(i) center. Oxo complex 2 can be chemically reduced using Na/Hg or Ph₃C^• to afford the Zr^IV/Co⁰ complexes [(μ-Na)OZr(MesNPⁱPr₂)₃CoCN^tBu]₂ (3) and Ph₃COZr(MesNPⁱPr₂)₃CoCN^tBu (4), respectively. Based on the cyclic voltammogram of 2, Ph₃˙ should not be sufficiently reducing to achieve the chemical reduction of 2, but sufficient driving force for the reaction is provided by the nucleophilicity of the terminal oxo fragment and its affinity to bind Ph₃C⁺. Accordingly, 2 reacts readily with [Ph₃C][BPh₄] and Ph₃CCl to afford [Ph₃COZr(MesNPⁱPr₂)₃CoCN^tBu][BPh₄] ([5][BPh4]) and Ph₃COZr(MesNPⁱPr₂)₃CoCl (6), respectively. The chemical oxidation of 2 is also investigated, revealing that oxidation of 2 is accompanied by immediate hydrogen atom abstraction to afford the hydroxide complex [HOZr(MesNPⁱPr₂)₃CoCN^tBu]⁺ ([9]+). Thus it is posited that the transient [OZr(MesNPⁱPr₂)₃CoCN^tBu]⁺ [2]⁺ cation generated upon oxidation combines the basicity of a nucleophilic early metal oxo fragment with the oxidizing power of the appended cobalt center to facilitate H-atom abstraction.

Bimetallic cooperativity is demonstrated with a Co/Zr complex featuring both nucleophilic Zr(iv) oxo and redox active Co sites.     

Spectral simplification in proton magnetic resonance spectrometry for 3-(4-aminophenyl)-3-ethyl-2,6-piperidinedione (aminoglutethimide) with achiral and chiral lanthanide shift reagents

The 60-MHz ¹H-NMR spectra of racemic aminoglutethimide (A; 3-(4-aminophenyl)-3- ethyl-2,6-piperidinedione) are studied with the achiral shift reagent, tris(6,6,7,7,8,8,8- heptafluoro-2,2-dimethyl-3,5-octanedionato)europiura(III) (B) and the chiral reagents, tris[3-(trifluororaethylhydroxyraethylene)-D-caraphorato]europium(III) (C) and tris[3- heptafluoropropylhydroxyraethylene-D-caraphorato]europiura(III) (D). Appreciable values of the enantioraeric shift difference, ΔΔδ, were observed for both sets of aryl protons and the methyl protons in CDCl₃ solutions ar 28°C with added C or D. Optical purity determinations were done with good reliability by using the methyl resonance and a D:A molar ratio near 0.5. Results are discussed in terms of possible coordination of the europiura at the amine or amide carbonyl groups. Some significant differences in results with B, C and D were noted.     

1H NMR Spectral Simplification with Achiral and Chiral Lanthanide Shift Reagents. Ethchlorvynol. Novel Behavior of a Terminal Alkyne with Ag(I) - Lanthanide Binuclear Shift Reagent

The 60 MHz ¹H NMR spectra of racemic ethchlorvynol, 1, have been studied at 28° in CDCl₃ solution with the achiral reagent tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)europium(III).     

Session 3 bioprocessing research

Applied Biochemistry and Biotechnology -     

Identification of inhibitory components toxic toward zymomonas mobilis CP4(pZB5) xylose fermentation

Zymomonas mobilis CP4(pZB5) is a recombinant bacterium that can produce ethanol from both xylose and glucose. The ethanol-producing efficiency of this organism is substantially impeded by toxic substances present in pretreated hydrolyzates or solid biomass substrates. Acetic acid and furfural (a pentose degradation product) are highly toxic to this organism at levels envisioned for a pretreated-hardwood liquid hydrolyzate. In addition, lignin degradation products and 5-hydroxymethylfurfural (a hexose degradation product) have a moderately toxic effect on the organism. Of the compounds studied, organic acids and aldehydes were found to be more inhibitory than lignin acids or the one alkaloid studied. Acetone:water and methanol extracts of solid biomass samples from red oak, white oak, and yellow poplar are toxic toZymomonas cell growth and ethanol production, with the extracts from white oak being the most toxic.     

1H NMR Spectral Simplification with Achiral and Chiral Lanthanide Shift Reagents. IV. Metaxalone, 5-(3,5-Dimethylphenoxymethyl)-2-oxazolidinone; Evidence for Multidentate Chelation

The 60 MHz ¹H NMR spectra of racemic metaxalone, 1, have been studied in CDC1₃ solution at 28° with the achiral shift reagent tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato)europium(III), 2, and the chiral reagents tris[3-(trifluoromethylhydroxymethylene)-d-cam-phorato]europium(III), 3, and tris[3-(heptafluoropropylhydroxymethylene)-d-camphorato]europium(III), 4. Reagent 3 produced modest observable enantiomeric shift differences, ΔΔδ, for the CH₂0, aryl methyl, aryl H₂,6 and the NH siqnals. Although reaquent 4 produced small or no observable ΔΔδ for the CH₂0, aryl methyls or aryl protons. strikingly qreater valuesof lanthanide induced shift, Δδ, as well as ΔΔδ, were found for the NH signal using 4 relative to 3. Analytical feasibility for direct optical purity determinations of 1 with 0 using this NH siqnal sclould allow detection of 74% of the minor enantiomer or less. Results are discussed ir terms of potential bidentate or tridentate chelation of 3 by 1 makinrl a greater contribution than for 4.     

Synthesis of conformationally constrained benzoylureas as BH3-mimetics

The design of small molecules that mimic the BH3 domain and bind to Bcl-2 proteins has emerged as a promising approach to discovering novel anti-cancer therapeutics. We reveal the design and synthesis of conformationally constrained benzoylurea scaffolds as conformational probes. Central to helix mimicry, the intramolecular hydrogen bond in the benzoylurea plays a key role in the pre-organisation of the acyclic substrates for cyclisation via ring closing metathesis, providing efficient access to the constrained mimetics.     

Detailed material balance and ethanol yield calculations for the biomass-to-ethanol conversion process

Applying material balance calculations to the evaluation and optimization of lignocellulosic biomass conversion processes is fundamentally important. The lack of a general framework for material balance calculations and inconsistent compositional analysis data have made it difficult to compare results from different research groups. Material balance templates have been developed to follow accurately the distribution of carbon in lignocellulosic substrates through the pretreatment and simultaneous saccharification and fermentation (SSF) processes, and provide information on overall carbon recovery, recovery of individual sugars, and solubilization of biomass components. Based on material balance considerations, we developed equations that allow us to compute overall ethanol yields for biochemical conversion of biomass correctly.