Using theozymes for designing transition‐state analogs for the intramolecular aldol reaction of δ‐diketones

Two theozymes for the intramolecular aldol reaction of δ‐diketones have been studied using ab initio methods. The presence of both acid/base residues favors several steps of the aldol reaction. The appropriate positioning of these residues can accelerate one of two diastereromeric reaction pathways, the catalyzed aldol reaction being highly stereoselective. Analysis of the geometrical parameters, charge distribution, and the shape of molecular electrostatic potential for the corresponding acid/base catalyzed transition structure allows us to design adequate transition‐state analogs to favor a reactive channel of this intramolecular aldol reaction. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 338–347, 2001     

Isolation and characterization of soybean NBS analogs

Isolation of plant resistance genes is greatly helpful to crop resistance breeding and the insight of resistance mechanism. The cloned plant resistance genes are classified into four classes according to their putative structural domain, of which the majority possesses nucleotide-binding site (NBS) domain that consists of P-loop, kinase2a and kinase3a. The conservation of this domain affords the potential possibility of cloning the plant resistance genes, which is homology-based cloning technique. In the present study, the degenerate oligonucleotide primers were designed according to the tobaccoN andArabidopsis RPS2, and 358 clones were isolated from the genomic DNA of resistance soybean cultivar Kefengl, resistant to soybean mosaic virus, and 4 open-reading NBS analogs were finally characterized and designated asKNBS1, KNBS2, KNBS3 andKNBS4. Southern hybridization suggested that they were present with multicopy in the soybean genome;KNBS4 was mapped to F linkage group andKNBS2 co-located J linkage group with the SCAR marker ofRsa resistant to soybean mosaic virus by RFLP analysis. Northern analysis suggested thatKNBS2- related sequence was low and constitutively expressed in the root, stem and leaves of soybean. The detailed characterization of NBS analogs is very helpful to ultimately cloning the soybean resistance gene.     

Synthetic analogs of naturally occurring flavolignans. XI. Reaction of synthetic flavone analogs with hydrazine hydrate and its derivatives

Reactions of 1,3-benzodioxane and 1,4-benzodioxane analogs of flavones with hydrazine derivatives are studied. The hydrazines recyclize the new flavones into 3,5-diarylpyrazoles. Their PMR spectra confirm their structures.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–41, January–February, 2000.     

A solid phase approach to PDMP analogs：A general strategy for combinatorial library

The present work reports the first solid phase synthesis of biologically interesting D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol(D-threo-PDMP)derivatives.This synthetic strategy includes facile preparation of versatile azido intermediate(5) in a relatively short sequence and the subsequent derivatization of 5,which led to a series of sulfonamide,urea and heterocycle substituted PDMP analogs(10 and 10’).With this method,a 5280-member compound library has been successfully built by IRORI Nanokan? system.     

Novel stilbene‐based Fischer base analog of leuco‐TAM – (2E,2′Z)‐{2‐(4‐(E)‐styrylphenyl)propane‐1,3‐diylidene}bis(1,3,3‐trimethylindoline) – derivatives: synthesis and structural consideration by 1D NMR and 2D NMR spectroscopy

We report the synthesis of a series of novel stilbene‐based (St) Fischer base analogs of leuco‐triarylmethane (LTAM) dyes by treating Fischer base with (E)‐4‐styrylbenzaldehyde derivatives. All St‐LTAM molecules examined herein are characterized by 1D and 2D NMR. They were found to exhibit ZE configuration and isomerize to their diastereomers EE and ZZ in 2–3 h. They exhibit type I behavior of diastereomeric isomerization. Copyright © 2015 John Wiley & Sons, Ltd.     

Plant-Based Seafood Analogs

There is a growing global need to shift from animal- towards plant-based diets. The main motivations are environmental/sustainability-, human health- and animal welfare concerns. The aim is to replace traditional animal-based food with various alternatives, predominantly plant-based analogs. The elevated consumption of fish and seafood, leads to negative impacts on the ecosystem, due to dwindling biodiversity, environmental damage and fish diseases related to large-scale marine farming, and increased intake of toxic substances, particularly heavy metals, which accumulate in fish due to water pollution. While these facts lead to increased awareness and rising dietary shifts towards vegetarian and vegan lifestyles, still the majority of seafood consumers seek traditional products. This encourages the development of plant-based analogs for fish and seafood, mimicking the texture and sensorial properties of fish-meat, seafood, or processed fish products. Mimicking the internal structure and texture of fish or seafood requires simulating their nanometric fibrous-gel structure. Common techniques of structuring plant-based proteins into such textures include hydrospinning, electrospinning, extrusion, and 3D printing. The conditions required in each technique, the physicochemical and functional properties of the proteins, along with the use of other non-protein functional ingredients are reviewed. Trends and possible future developments are discussed.     

Synthesis of Optically Active 1,4-Dioxane Nucleotide Analogs

Optically active nucleotide analogs were prepared that were composed of a 1,4-dioxane ring as the sugar analog to which either uracil or adenine attached together with two carboxylic ester groups, to be used as vehicles for formation of oligomers. The chiral 1,4-dioxane moiety was constructed from dimethyl L-tartrate via the corresponding (2R,3R)-dimethyl 2-O-allyl-tartrate.     

Contribution and limits of a non‐intrusive Raman spectroscopic method compared with HPLC for routine application to pre‐delivery analytical control of two major camptothecin analogs: irinotecan and topotecan

The purpose of this study was to develop a Raman spectroscopy (RS) method as an effective tool for the non‐intrusive pre‐delivery analytical quality control (AQC) of two camptothecin analogs, i.e. irinotecan (IRI) and topotecan (TPT), which are prescribed and compounded at the hospital. Following a phase of analytical pre‐validation, based on the actual conditions of use of the analogs, the protocol was validated and compared with the reference high‐performance liquid chromatography (HPLC) method. For IRI, AQC by RS has been validated in ranges from 0.94 to 3.27 mg/ml in saline solutions and from 0.89 to 3.30 mg/ml in dextrose solutions. These ranges recover the entire therapeutic concentrations encountered in clinical practice, i.e. 1.08–2.8 mg/ml. The RS and HPLC methods were validated by calculating the accuracy profile and provided excellent results for the analytical validation key criteria. The Spearman and Kendall correlation tests (p‐value < 1.10⁻¹¹) and the statistical studies performed on the Bland and Altman graphs confirm a strong correlation between RS and HPLC results. However, we show that a routine apparatus is unable to quantify TPT therapeutic concentrations ranging between 25 and 50 µg/ml but that a sufficiently powerful RS bench is able to detect and quantify TPT. Overall, these results confirm the potential of the RS option for future innovative applications. Owing to its analytical and practical qualities, this promising method contributes to the improvement of the safety of the medication circuit at the hospital and to the protection of caregivers and their working environment. Copyright © 2015 John Wiley & Sons, Ltd.     

Novel 1,2,3-Triazole Derivatives as Mimics of Steroidal System—Synthesis,Crystal Structures Determination,Hirshfeld Surfaces Analysis and Molecular Docking

Herein, we present the synthesis and crystal structures determination of five 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives containing halogen atoms, 6a–e, which may be used as an excellent mimic of steroids in the drug development process. Good quality crystals obtained for all of the synthesized compounds allowed the analysis of their molecular structures. Subsequently, the determined crystal structures were used to calculate the Hirshfeld surfaces for each of the synthesized compounds. Furthermore, results of our docking studies indicated that synthesized derivatives are able to bind effectively to the active sites of selected enzymes and receptors involved in the hormone biosynthesis and signaling pathways, analogously to the native steroids.