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BACKGROUND: Protein oxidation during food processing causes changes in the balance of protein–molecular interactions and protein–water interactions, ultimately leading to protein denaturation, which results in the loss of a range of functional properties. Therefore, how to control the oxidative modification of proteins during processing has been the focus of research. RESULTS: In the present study, the intrinsic fluorescence value of the myofibrillar proteins (MP) decreased and the surface hydrophobicity value increased, indicating that the heat treatment caused a significant change in the conformation of the MP. With an increase in heating temperature, protein carbonyl content increased, total sulfhydryl content decreased, and protein secondary structure changed from α‐helix to β‐sheet, indicating that protein oxidation and aggregation occurred. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that heat treatment can lead to the degradation of proteins, especially myosin heavy chain, although actin had a certain thermal stability. In total, 733 proteins were identified by proteomics, and the protein oxidation caused by low temperature vacuum heating (LTVH) was determined to be mild oxidation dominated by malondialdehyde and 4‐hydroxynonenal by oxidation site division. CONCLUSION: The present study has revealed the effect of LTVH treatment on the protein oxidation modification behavior of sturgeon meat, and explored the effect mechanism of LTVH treatment on the processing quality of sturgeon meat from the perspective of protein oxidation. The results may provide a theoretical basis for the precise processing of aquatic products. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Based on field investigations as well as morphological and molecular systematic studies we found a new species of Bothriospermum which can be easily distinguished from all other known congeneric species by its unlobed faucal appendages and very long styles. We conducted molecular phylogenetic analyses based on a combined dataset from nrITS, plastid rps16, trnL‐trnF and trnG‐trnS regions. The results indicated that the new species indeed belongs in Bothriospermum and that it is well separated from other congeneric clusters, but that the genus Bothriospermum is paraphyletic with Nihon and Thyrocarpus clusetered within it. As a result, Bothriospermum longistylum sp. nov. is described and illustrated here. A revised key to species of Bothriospermum and a distributional map are also presented. [ABSTRACT FROM AUTHOR]

The micro-morphology of nutlets in 30 taxa (28 species and 2 varieties) of Microula Benth. (Boraginaceae) was surveyed by light and scanning electron microscopy. A principal coordinate-based ordination analysis (PCO) (8 morphological and 14 micro-morphological characters) was applied to explore whether taxa clustered according to the current sectional taxonomy. The nutlet epidermis showed three major features: trichomes, papillae and lamellae. Two basic trichome types could be identified: branched and unbranched. Stellate trichomes (STT) and stipitate stellate trichomes (SST) can be considered as two subtypes of branched trichomes based on shape and branching location. Three kinds of unbranched trichomes were recognized by their shapes: slender trichomes (SLT), spear-like trichomes (SPT) and conical trichomes (CT). Four types of papillae were revealed in this genus: central apiculate papillae (CAP), debris-covered convex papillae (DCP), rugous papillae (RP) and tabular papillae (TP). The lamellae was classified in five types: glossy lamellae (GL), thread-like lamellae (TL), rugous lamellae (RL), interrupted lamellae (IL) and debris-covered lamellae (DCL). The variation in the nature of surface sculpturing, nutlet shape and size, dorsal aperture shape, and attachment scar positions proved useful diagnostic characters. Taxa belonging to the same section generally clustered together in the PCO analysis. A key based on the morphology and micro-morphology of nutlets is provided to distinguish the sections of Microula. The presence of SLT, STT, DCP and DCL is consistent with the macro-morphological classification and provides additional evidence for the subgeneric delimitations. The SST, SLT, CAP, DCP, RP, DCL, GL and RL are useful in discriminating species in Microula. Additionally, the distribution of some trichomes, papillae and lamellae types is correlated with the altitudinal distribution of the species. [ABSTRACT FROM AUTHOR]

7′-Hydroxyriccardin C ( 1) and marchantin E ( 2), two macrocyclic bisbibenzyls with a stereogenic center at the ethylene bridge from Chinese liverworts, were investigated stereochemically. Compound 1 was found to be optically active and occurred as a pair of dynamically interchangeable atropisomers at room temperature due to the low barrier of rotation around the biaryl bond, while 2 was a racemic mixture, which was successfully resolved by chiral HPLC into two enantiomers. Their absolute configurations were unequivocally assigned by analysis of temperature-dependent NMR spectra, X-ray crystallographic diffraction, and comparison of experimental and calculated ECD data. [ABSTRACT FROM AUTHOR]

In the title complex, {[MnHg(SCN)4(H2O)2]·2C4H9NO} n, each Mn atom is octahedrally coordinated to four equatorial thio­cyanate N atoms and two axial water O atoms. The Mn atom and two O atoms lie on a twofold axis. Two kinds of crystallographically independent Hg atoms (denoted Hg1 and Hg2) are tetrahedrally coordinated with four thiocyanate S atoms and each Hg atom lies on a axis. N, N-Di­methyl­acet­amide mol­ecules are connected to coordinated water mol­ecules through hydrogen bonds. Each pair of Mn and Hg atoms is bridged via one thiocyanate ion. An Mn2Hg1Hg2(SCN)4 16-membered ring is formed as a unit and the four metal atoms are in a chair-form tetrahedral arrangement. The units are linked with one another and form infinite two-dimensional networks. [ABSTRACT FROM AUTHOR]

In the title complex, [MnHg(SCN)4(C2H6SO)2] n, each Hg atom is tetrahedrally coordinated to four S atoms of the SCN ions, while each Mn atom is octahedrally coordinated to four N atoms of the SCN ions and two O atoms of the di­methyl sulfoxide mol­ecules which occupy the trans positions. Each pair of Hg and Mn atoms is bridged by one SCN ion. Two Mn atoms, two Hg atoms and four SCN ions make a 16-membered ring which organises into a two-dimensional network. The di­methyl sulfoxide ligands are extended perpendicular to the plane on both sides. [ABSTRACT FROM AUTHOR]

In the title complex, [Hg(CH4N2S)4][Mn(NCS)4], the Hg and Mn atoms sit at special positions with symmetry and are tetrahedrally coordinated to four thio­urea (TU) S and four thio­cyanate (SCN) N atoms, respectively. The structure consists of discrete cationic and anionic [Hg(TU)4]2+ and [Mn(SCN)4]2− complexes, and weak NTU-H⃛SSCN hydrogen-bond bridges exist between these complexes. [ABSTRACT FROM AUTHOR]

In the title complex, [MnHg(NCS)4(C3H8O2)] n, each Hg atom is tetrahedrally coordinated with four S atoms of the SCN− ions, and each Mn atom is octahedrally coordinated with four N atoms of the SCN− ions, one hydroxyl O atom and one ethereal O atom of the glycol mono­methyl ether mol­ecule. Each pair of Hg and Mn atoms is bridged by one SCN− ion. A 24-membered Mn3Hg3(SCN)6 ring is formed as the strucrural unit, with the six metal atoms in a chair-form hexagonal arrangement. The units are condensed and linked three-dimensionally in the crystal resulting in a diamond-like structure. [ABSTRACT FROM AUTHOR]

MnHg(SeCN)4 has a three-dimensional network in which slightly distorted MnN4 and HgSe4 tetra­hedra (symmetry ) are connected by –SeCN– bridges. [ABSTRACT FROM AUTHOR]

The CdII ion in the title complex, [Cd(SCN)2{SC(NH2)2}2]∞, is situated at a centre of symmetry, and is bound to two N atoms belonging to thio­cyanate groups and to four S atoms of bridging thio­urea ligands. The structure consists of infinite chains of slightly distorted edge-shared Cd-centred octahedra. The bridging S atoms of two thio­urea ligands comprise the common edge. Some thermal properties are described. [ABSTRACT FROM AUTHOR]

The title complex, {[CdHg(SCN)4(C4H9NO)2]2} n, contains two crystallographically independent CdII centres and two HgII centres. Each CdII atom is bound to four N atoms belonging to SCN groups and to two O atoms from N, N-di­methyl­acet­amide (DMA) ligands in an octahedral geometry. Each HgII centre is tetrahedrally coordinated by four SCN S atoms. [ABSTRACT FROM AUTHOR]

In the title compound, Bi2B8O15, the Bi atom is coordinated to five or six O atoms. The B atoms exhibit two kinds of hybridization, sp2 and sp3, seen in the BO3 triangles and BO4 tetrahedra, respectively. Three BO3 triangles are connected to form a B3O6 planar ring. All atoms in the structure are connected together to form an infinite three-dimensional network. [ABSTRACT FROM AUTHOR]

The title complex, [MnHg(SCN)4(CH4N2O)3] n, consists of slightly distorted octahedral MnN3O3 and tetrahedral HgS4 units. The MnII atom is coordinated by the O atoms of three urea mol­ecules and by the N atoms of three SCN− ions; HgII is coordinated by four S atoms from SCN− ions. Each pair of MnII and HgII atoms is connected by an -SCN- bridge, forming infinite two-dimensional -Mn-NCS-Hg- networks. [ABSTRACT FROM AUTHOR]

The complete mol-ecule of the title compound, C(28)H(28)B(2)Br(4)O(4), is generated by the application of a centre of inversion. In the mol-ecule, the BO(2) plane is perpendicular to that through the pyrene ring [dihedral angle = 86.27 (13)°]. In the crystal, mol-ecules stack into columns along the b axis, the closest contact between these being of the type C-Br⋯π.

In the title one-dimensional coordination polymer, {[Mn(C(5)O(5))(C(10)H(8)N(2))(H(2)O)].H(2)O}(n), each Mn(II) ion is seven-coordinated by four O atoms from two croconate ligands, two N atoms from a 2,2'-bipyridine (2,2'-bipy) ligand and one O atom from an aqua ligand. The croconate ligand bridges the Mn(II) ions in a bis-bidentate chelation mode, forming an extended [Mn(C(5)O(5))](n) chain running parallel to the [001] direction, with the lipophilic 2,2'-bipy ligands lying along one side and the hydrophilic water molecules along the opposite side. Coordinated water and solvent water molecules are arranged in the hydrophilic layer, which is characterized by O-H...O hydrogen bonds between croconate ligands. Meanwhile, 2,2'-bipy ligands from adjacent chains partially overlap and exhibit pi-pi interactions to form a lipophilic layer. The hydrophilic and lipophilic layers are arranged alternately to build a layer structure.

The title sulfur-rich organic molecular crystals, namely EDTO-TTP (C(9)H(4)OS(8)) and VDTO-TTP (C(9)H(2)OS(8)), are characterized by conjugated C-S bonds and S...S intermolecular short contacts. The planar EDTO-TTP molecules are parallel packed and exhibit strong intermolecular interactions, including side-by-side transverse S...S contacts, face-to-face longitudinal pi-pi interactions and C-H...O hydrogen bonding. On cooling the EDTO-TTP crystal from 220 to 120 K, the cell dimensions and the intermolecular distances (such as S...S contacts and especially pi-pi spacings) become shorter, while the intramolecular bonds become longer. The curved VDTO-TTP molecules are packed in such a way as to make the crystal fully depolarized. The intermolecular interactions of the VDTO-TTP crystal are relatively weak, because of the weak pi-pi interactions and the lack of hydrogen bonding.

In the title compound, C(31)H(27)N(3), the cyclo-hexene ring has an envelope configuration. In the crystal structure, there is an 34 Å(3) void around the inversion center, but the low electron density (0.13 e Å(-3)) in the difference Fourier map suggests no solvent mol-ecule occupying this void. No hydrogen bonding is found in the crystal structure.

The title compound, [Ni(C(5)O(5))(C(10)H(8)N(2))(2)], lies across a crystallographic twofold axis, around which two 2,2'-bipyridine (2,2'-bipy) ligands are arranged in a propeller manner. The local geometry of the NiN(4)O(2) coordination core basically adopts an octa-hedral geometry. The mol-ecular twofold axis is along the direction of the mol-ecular dipole moment, and the complex is packed with its dipole moment alternately along the +b and -b directions. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

In the two title complexes, (C24H20P)[Au(C3S5)2] x C3H6O, (I), and (C20H20P)[Au(C3S5)2], (II), the Au(III) atoms exhibit square-planar coordinations involving four S atoms from two 2-thioxo-1,3-dithiole-4,5-dithiolate (dmit) ligands. The Au-S bond lengths, ranging from 2.3057 (8) to 2.3233 (7) A in (I) and from 2.3119 (8) to 2.3291 (10) A in (II), are slightly smaller than the sum of the single-bond covalent radii. In (I), there are two halves of independent Ph4P+ cations, in which the two P atoms lie on twofold rotation axis sites. The Ph4P+ cations and [Au(C3S5)2]- anions are interspersed as columns in the packing. Layers composed of Ph4P+ and [Au(C3S5)2]- are separated by layers of acetone molecules. In (II), the [Au(C3S5)2]- anions and EtPh3P+ counter-cations form a layered arrangement, and the [Au(C3S5)2]- anions form discrete pairs with a long intermolecular Au...S interaction for each Au atom in the crystal structure.

The title complexes, [M(C5O5)(C12H8N2)2], with M = Co(II), Ni(II) and Cu(II), all lie across twofold rotation axes, around which two 1,10-phenanthroline ligands are arranged in a chiral propeller manner. The Co(II) and Ni(II) complexes are isostructural, with octahedral coordination geometry, while the local geometry of the Cu(II) complex is severely distorted from octahedral.

In the title compound, [[K2Ni(C5O5)2(H2O)2].4H2O]n, the Ni atom lies on an inversion centre. Two inversion-related croconate [4,5-dihydroxy-4-cyclopentene-1,2,3-trionate(2-)] ligands and an Ni(II) ion form a near-planar symmetrical [Ni(C5O5)2]2- moiety. The near-square coordination centre of the moiety is then extended to an octahedral core by vertically bonding two water molecules in the [Ni(C5O5)2(H2O)2]2- coordination anion. The crystal structure is characterized by a three-dimensional network, involving strong K...O...K binding, K...O-Ni binding and hydrogen bonding.

The title compound, C13H6O4S5, possesses crystallographically imposed mirror symmetry, with the atoms of the C=S group lying on the mirror plane. It is an example of the general formula [RCO]2(dmit), where R is a furan ring and dmit is 2-thioxo-1,3-dithiole-4,5-dithiolate. The components exhibit some polarization of their molecular-electronic structure. The dmit and furan moieties exhibit a high degree of conjugation, as the introduction of C=O connecting the conjugated furan (donor) and dmit (acceptor) rings forms a good conjugated system with high delocalization. A polar three-dimensional framework is built from a combination of intermolecular contacts, namely SS interactions and C-HO hydrogen bonding. The structural characteristics lead to good second-order non-linear optical properties.

The title complex, [MnHg(NCS)4(C2H5NO)2]n, consists of slightly distorted MnN4O2 octahedra and HgS4 tetrahedra. Each Mn(II) cation is bound to four N atoms of the NCS groups and two O atoms of the N-methylformamide (NMF) ligands in a cis configuration. Each Hg(II) cation is coordinated to four S atoms of NCS groups. Each pair of Mn(II) and Hg(II) cations is connected by an -NCS- bridge, forming an infinite three-dimensional -Mn-NCS-Hg- network.

The structure of rubidium gadolinium bis(tungstate), RbGd(WO4)2, has been determined. The crystal is built up from corner- and edge-sharing WO6 octahedral and GdO8 polyhedral groups, giving rise to a Gd-WO4 polyhedral backbone surrounding structural cavities filled with Rb+ cations. The Gd and Rb atoms lie on twofold axes.

The title complex, [[CdHg(SCN)(4)(C(4)H(9)NO)(2)](2)](n), contains two crystallographically independent Cd(II) centres and two Hg(II) centres. Each Cd(II) atom is bound to four N atoms belonging to SCN groups and to two O atoms from N,N-dimethylacetamide (DMA) ligands in an octahedral geometry. Each Hg(II) centre is tetrahedrally coordinated by four SCN S atoms.

The Cd(II) ion in the title complex, [Cd(SCN)(2)[SC(NH(2))(2)](2)](infinity), is situated at a centre of symmetry, and is bound to two N atoms belonging to thiocyanate groups and to four S atoms of bridging thiourea ligands. The structure consists of infinite chains of slightly distorted edge-shared Cd-centred octahedra. The bridging S atoms of two thiourea ligands comprise the common edge. Some thermal properties are described.

In the title compound, Bi(2)B(8)O(15), the Bi atom is coordinated to five or six O atoms. The B atoms exhibit two kinds of hybridization, sp(2) and sp(3), seen in the BO(3) triangles and BO(4) tetrahedra, respectively. Three BO(3) triangles are connected to form a B(3)O(6) planar ring. All atoms in the structure are connected together to form an infinite three-dimensional network.

The title complex, [MnHg(SCN)4(CH4N2O)3]n, consists of slightly distorted octahedral MnN3O3 and tetrahedral HgS4 units. The Mn(II) atom is coordinated by the O atoms of three urea molecules and by the N atoms of three SCN- ions; Hg(II) is coordinated by four S atoms from SCN- ions. Each pair of Mn(II) and Hg(II) atoms is connected by an -SCN- bridge, forming infinite two-dimensional -Mn-NCS-Hg- networks.