582 Results Found

Hydrocarbon stapling is a useful tool for stabilizing the secondary structure of peptides. Among several methods, hydrocarbon stapling at i,i + 1 positions was not extensively studied, and their secondary structures are not clarified. In this study,...

Complexes between proteins are at the basis of almost every process in cells. Their study, from a structural perspective, has a pivotal role in understanding biological functions and, importantly, in drug development. X-ray crystallography represents...

Structure-based design and synthesis of two biphenyl-N-acyl-β-d-glucopyranosylamine derivatives as well as their assessment as inhibitors of human liver glycogen phosphorylase (hlGPa, a pharmaceutical target for type 2 diabetes) is presented. X-...

A model for parasitic motility has been proposed in which parasite filamentous actin (F-actin) is attached to surface adhesins by a large component of the glideosome, known as the glideosome-associated connector protein (GAC). This large 286 kDa prot...

The gene encoding frog (Xenopus tropicalis) ependymin without the signaling sequence was gene-synthesized, and the protein successfully over-expressed in ~mg quantities adequate for crystallization using insect cell expression. Circular dichroism (CD...

Pif1 proteins are DNA helicases belonging to Superfamily 1, with 5′ to 3′ directionality. They are conserved from bacteria to human and have been shown to be particularly important in eukaryotes for replication and nuclear and mitochondri...

The molecule glycerol (H3gly) plays a key role in sustainable and green chemistry. Having been discovered for over 200 years and produced from vegetable oils and animal fats by hydrolysis, saponification and transesterification reactions, this natura...

Chronic myeloid leukemia is a multistep, multi-lineage myeloproliferative disease that originates from a translocation event between chromosome 9 and chromosome 22 within the hematopoietic stem cell compartment. The resultant fusion protein BCR::ABL1...

d-Tagatose, classified as a rare sugar, exhibits notable biological activities, including its function as a low-calorie sweetener. The three-dimensional configuration of carbohydrates is crucial for elucidating their functional properties. Numerous s...

The title compound was obtained in low yield and spectroscopically characterised. Its X-ray structure was compared with the X-ray structures of other crystallographically-characterised 2-unsubstituted 1,3-dithiolanes.

Cyclic-olefin-copolymer (COC)-based microfluidic devices are increasingly becoming the center of highly valuable research for in situ X-ray measurements due to their compatibility with X-rays, biological compounds, chemical resistance, optical proper...

The focus of structural biology is shifting from the determination of static structures to the investigation of dynamical aspects of macromolecular function. With time-resolved macromolecular crystallography (TRX), intermediates that form and decay d...

The X-ray structure of the title compound has been determined and the structure shows an exo-configured planar dithiolanone ring. This is in contrast to the few previous dithiolanones to be characterised crystallographically, which are all twisted.

In the present study, the local atomic structure of a Nb3Sn superconductor sample has been probed by X-ray absorption fine structure (XAFS) as a function of hydrostatic pressure (from ambient up to 26 GPa) using a diamond anvil cell set-up. The analy...

Compositional and anatomical studies of silicified wood have been carried out extensively all around the world. The classification of silicified wood as such deals with all the forms and phases of silica that come under its umbrella. One such class o...

Serial crystallography (SX) is an emerging X-ray crystallographic method for determining macromolecule structures. It can address concerns regarding the limitations of data collected by conventional crystallography techniques, which require cryogenic...

The phosphole ring is known as a useful building block for constructing π-conjugated organic materials. Here, we report ladder-type benzophospholo[3,2-b]indole (BPI) derivatives where the phosphole and the pyrrole rings are directly fused. Compoun...

The title compound was obtained in moderate yield by a new and unexpected base-induced ring contraction from a 1,4-thiazine precursor. Its X-ray structure showing hydrogen bonded dimers was compared with those of other crystallographically characteri...

X-ray crystallographic methods can be used to visualize macromolecules at high resolution. This provides an understanding of molecular mechanisms and an insight into drug development and rational engineering of enzymes used in the industry. Although...

Time-resolved in-house macromolecular crystallography is primarily limited by the capabilities of the in-house X-ray sources. These sources can only provide a time-averaged structure of the macromolecules. A significant effort has been made in the de...

Serial crystallography (SX) enables the determination of room-temperature structures with minimal radiation damage. The photon flux of the pink beam of 1.2% bandwidth (BW) is one order higher than that of the monochromatic beam from a silicon crystal...

Structures of some hydrogenated products and intermediates, prepared by a heterogeneous Pd/C or Ru/C catalyst starting from 4-pyridinecarbonitrile (4PN), in water and in the presence of an acidic additive (HCl or H2SO4), were confirmed in various sal...

A series of quinoxaline 1,4-di-N-oxide analogues were prepared from benzofurazan N-oxide derivatives and β-diketone ester compounds by the improved Beirut reaction. The structures of the target products were characterized by NMR, MS, IR and elemental...

In the present study, we have developed a series of compounds [M(tcm)2(bix)4]n [where M = Co (1), Ni (2), and Cu (3)] using tricyanomethanide (tcm) and 1,4-bis(imidazol-1-ylmethyl)benzene (bix) ligands. The compounds were characterized by elemental a...

This Special Issue of Chemistry is dedicated to Dr. Howard D. Flack (1943–2017), a renowned crystallographer who transformed the way in which, by using single crystal X-ray diffraction, we are able to determine the absolute structure of a crystalline...

As electrolyte materials for proton conductive fuel cells, perovskite-type materials such as barium cerates and barium zirconates have received a lot of attention due to their high protonic conduction at intermediate temperatures. Yet, the crystallin...

This work presents details of the synthesis, properties and structure of a novel neptunium carbonate (NH4)[NpO2CO3], a member of the M[AnO2CO3] (M = K, (NH4), Rb, Cs) class of compounds. Carbonates play an important role in the migration of actinides...

Two new antimicrobial bisabolane-type sesquiterpenoid derivatives, ent-aspergoterpenin C (compound 1) and 7-O-methylhydroxysydonic acid (2), and two new butyrolactone-type monoterpenoids, pestalotiolactones C (3) and D (4), along with a known monoter...

We report the growth of single crystals and X-ray diffraction characterization of the quasi-one-dimensional spin chain compound, Li2CuO2. The single crystals were grown using the high-temperature solution growth technique. The resulting blade-shaped...

In spite of the enormous biological and clinical significance of penicillin-binding protein (PBP)/β-lactamase (βL), few of their many homologs (PBP)/βLs homologs) have been studied crystallographically, and have known functions. Herein, X-ray crystal...

The reaction of 1,8-diaminooctane with hydroiodic acid in the presence of iodine gave a new polyiodide-containing salt: 1,8-diaminiumoctane bis(triiodide), (H3N-(CH2)8-NH3)[I3]2. The title compound has been characterized by crystallographic and spect...

One-pot synthesis of (E)-5-[bromo(phenyl)methylene]-4-phenyl-2-(p-tolyl)-4,5-dihydrooxazole (9) from propargylic alcohol 5 and p-toluamide (6) was achieved via gold(III)-catalyzed propargylic substitution, followed by gold(III)-catalyzed bromocycliza...

The ternary Cr-Fe-Si system was investigated with X-ray diffraction, energy dispersive X-ray spectrometry, scanning and transmission electron microscopy, and electron diffraction. Samples melted at 1723 K were examined right after cooling or after an...

Four different new Schiff basses tethered indolyl-triazole-3-thione hybrid were designed and synthesized. X-ray single crystal structure, tautomerism, DFT, NBO and Hirshfeld analysis were explored. X-ray crystallographic investigations with the aid o...

A mild and efficient two-step synthesis of 3-substituted β-carbolinone derivatives from 3-substituted β-carboline in good yields is described. A possible reaction mechanism for the formation of the skeleton of β-carbolin-1-one is proposed. The struct...

Yellow pigments, fomitellanols A (1a) and B (2a), and drimane-type sesquiterpenoid ethers of isocitric acid, cryptoporic acids P (3) and Q (4), have been isolated from the fruiting bodies of Fomitella fraxinea (Polyporaceae). Their structures were es...

The authors wish to inform readers that there are several minor errors and omissions in the chemical structures of compounds 1–3 shown in Figure 1 of this paper [1]. Their structures were re-elucidated by detailed analysis of the NMR, MS, and X-ray c...

The catalytic cycle of the oxygen-evolving complex (OEC) of photosystem II (PSII) comprises five intermediate states Si (i = 0–4), from the most reduced S0 state to the most oxidized S4, which spontaneously evolves dioxygen. The precise geometr...

Ever since the first structure of an enzyme, lysozyme, was solved, scientists have been eager to explore how these molecules perform their catalytic function. There has been an overwhelmingly large body of publications that report the X-ray structure...

The Flack Parameter is now almost universally reported for all chiral materials characterized by X-ray crystallography. Its elegant simplicity was an inspired development by Howard Flack, and although the original algorithm for its computation has be...

Grazing incidence small- and wide-angle X-ray scattering (GISAXS, GIWAXS) has been widely applied for the study of functional thin films, be it for the characterization of nanostructured morphologies in block copolymers, nanocomposites, and nanoparti...

The bioactive natural product perophoramidine has proved a challenging synthetic target. An alternative route to its indolo[2,3-b]quinolone core structure involving a N-chlorosuccinimde-mediated intramolecular cyclization reaction is reported. Attemp...

Proteins that use cysteine residues for catalysis or regulation are widely distributed and intensively studied, with many biomedically important examples. Enzymes where cysteine is a catalytic nucleophile typically generate covalent catalytic interme...

Single-crystal X-ray diffraction structures of organotin compounds bearing hemicarbonate and carbonate ligands were recently reviewed by us—“CO2 Derivatives of Molecular Tin Compounds. Part 1: Hemicarbonato and Carbonato Complexes”, Inorganics 2020,...

Five new compounds, including a benzopyran ribonic glycoside, daldiniside A (1), two isocoumarin ribonic glycosides, daldinisides B (2) and C (3), and two alkaloids, 1-(3-indolyl)-2R,3-dihydroxypropan-1-one (4) and 3-ethyl-2, 5-pyrazinedipropanoic...

The determination of tungsten oxidation states and W–ligand bond lengths for pyranopterin tungsten enzymes can be negatively impacted by Fourier series termination effects and photodamage/photoreduction in the X-ray beam. As a result, a new set...

In the present work, the effect of Si addition on the magnetic properties of Fe60−xCo25Ni15Six (x = 0, 5, 10, 20, and 30 at%) alloys prepared by mechanical alloying was analyzed by X-ray diffraction and magnetic vibrating sample magnetometry an...

Chiral electroactive materials have attracted attention for the effects of electrical magnetochiral anisotropy (eMChA) and chirality-induced spin selectivity (CISS). The combination of tetrathiafulvalene (TTF) with chiral moieties is one way to acces...

A new double perovskite compound with nominal composition Y2MgRuO6 is synthesized by the floating zone technique. X-ray diffraction measurements reveal a monoclinic crystal structure with space group P21/n and monoclinic angle β = 90.178(1)ͨ...

Single crystal diamond has been recognized as the optimal tool material in ultra-precision machining. However, the excessive tool wear prevents it from cutting ferrous materials. This paper conducts a series of thermal analysis tests under the condit...