Radikal fur Redoxstudien: Die Photolyse von [Cp*P{W(CO)5}2] mit einem Diphosphen verlauft uber ein radikalisches Intermediat und liefert ein luftstabiles komplexiertes Triphosphaallylradikal, in dem das ungepaarte Elektron gleichmasig uber beide terminale P-Atome verteilt ist. Die Oxidation des Radikals fuhrt zu dem lediglich bei tiefen Temperaturen in Losung stabilen Triphosphaallylkation, wahrend bei der Reduktion das stabile Triphosphaallylanion gebildet wird. Mes*=2,4,6-Tri-tert-butylphenyl.

Eine Familie mit komplexiertem Triphosphaallyl-Radikal, -Kation und -Anion [The Complexed Triphosphaallyl Radical, Cation, and Anion Family]

The synthesis of two η5 -aminoborole complexes of germanium(II) from the reaction of a germole dianion with aminoboron dichlorides is reported. This reaction constitutes a remarkable example of a germole-to-borole transformation. The two aminoborole complexes of germanium(II) were fully characterized by multinuclear NMR spectroscopy, IR spectroscopy, HRMS, and, in one case, by X-ray crystallography. The results of quantum-mechanical calculations favor the electronic structure of a half-sandwich complex of GeII over an ionic representation with a germanium dication stabilized by an aromatic aminoborole dianion.

A Neutral η5 -Aminoborole Complex of Germanium(II).

Recent years have witnessed remarkable advances in radical reactions involving main-group metal complexes. This includes the isolation and detailed characterization of main-group metal radical compounds, but also the generation of highly reactive persistent or transient radical species. A rich arsenal of methods has been established that allows control over and exploitation of their unusual reactivity patterns. Thus, main-group metal compounds have entered the field of selective bond formations in controlled radical reactions. Transformations that used to be the domain of late transition-metal compounds have been realized, and unusual selectivities, high activities, as well as remarkable functional-group tolerances have been reported. Recent findings demonstrate the potential of main-group metal compounds to become standard tools of synthetic chemistry, catalysis, and materials science, when operating through radical pathways.

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Main‐Group Metal Complexes in Selective Bond Formations Through Radical Pathways

Well-defined germylene cations [(i-Bu)2ATI]GeOTf (4) and [(i-Bu)2ATIGe][GaCl4] (5) are isolated, and the catalytic utility of compound 4 for the hydroboration of a variety of aldehydes and ketones is reported (ATI = aminotroponiminate).

Ge(ii) cation catalyzed hydroboration of aldehydes and ketones.

Bis(chlorogermyliumylidene) and its significant role in elusive reductive cyclization.

Direct coordination of a germanium(II) dicationic center to transition metals

Simple Summary Most diseases result in an imbalance of antioxidant defense, inflammatory responses, and membrane permeabilization. The current therapeutic modules of disease prevention are not fully effective and have some adverse effects on physiological parameters. In this vista, medicinal plants and their active compounds have proven to be effective against disease prevention and treatment. Ajwa dates have high nutritional value and are reported to possess antioxidant, anti-inflammatory, and antitumor properties. In the current in vitro study, Ajwa fruit pulp and seed extract were found to have strong antioxidant properties, stabilize the RBC membrane, and have a good protective capacity against protein denaturation. Besides this, the seed extract prevents glucose-mediated browning of BSA as well as inhibiting the development of cross-amyloid and AGEs formations. Molecular docking results confirm the interaction between functional residues of antioxidant enzymes and components of Ajwa fruit pulp and seed contents. Therefore, the consumption of Ajwa dates can be beneficial in disease prevention and treatment. However, more detailed study is required based on pharmacological aspects to determine the mechanisms of action of Ajwa dates’ components in disease prevention. Abstract This study investigated the health-promoting activities of methanolic extracts of Ajwa date seed and fruit pulp extracts through in vitro studies. These studies confirmed potential antioxidant, anti-hemolytic, anti-proteolytic, and anti-bacterial activities associated with Ajwa dates. The EC50 values of fruit pulp and seed extracts in methanol were reported to be 1580.35 ± 0.37 and 1272.68 ± 0.27 µg/mL, respectively, in the DPPH test. The maximum percentage of hydrogen peroxide-reducing activity was 71.3 and 65.38% for both extracts at 600 µg/mL. Fruit pulp and seed extracts inhibited heat-induced BSA denaturation by 68.11 and 60.308%, heat-induced hemolysis by 63.84% and 58.10%, and hypersalinity-induced hemolysis by 61.71% and 57.27%, and showed the maximum anti-proteinase potential of 56.8 and 51.31% at 600 μg/mL, respectively. Seed and fruit pulp inhibited heat-induced egg albumin denaturation at the same concentration by 44.31 and 50.84%, respectively. Ajwa seed showed minimum browning intensity by 63.2%, percent aggregation index by 64.2%, and amyloid structure by 63.8% at 600 μg/mL. At 100 mg/mL, Ajwa seed extract exhibited good antibacterial activity. Molecular docking analysis showed that ten active constituents of Ajwa seeds bind with the critical antioxidant enzymes, catalase (1DGH) and superoxide dismutase (5YTU). The functional residues involved in such interactions include Arg72, Ala357, and Leu144 in 1DGH, and Gly37, Pro13, and Asp11 in 5YTU. Hence, Ajwa dates can be used to develop a suitable alternative therapy in various diseases, including diabetes and possibly COVID-19-associated complications.

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Role of Ajwa Date Fruit Pulp and Seed in the Management of Diseases through In Vitro and In Silico Analysis

The adaptability of three acyclic tetradentate ligands with the –CHR–CHR– (R = H or alkyl substituent) linker in the backbone: bis(α-iminopyridine) L1 and the reduced form L2 and diaminodiphosphine L3 to stabilize various stannylenes has been explored. The reaction of L1 with two equivalents of Sn[N(SiMe3)2]2 led to the stabilization of a bisstannylene 1 through the ene-amide transformation of L1. The reaction of bisstannylene 1 with B(C6F5)3 and silver trifluoromethane sulfonate led to the formation of ligand stabilized Sn(II) dications 2 and 3 respectively. A mixture of Sn(II) dication 3 and a Sn(II) monocation 4 has been obtained from the reaction between 1 and trimethylsilyl trifluoromethane sulfonate. A 1 : 1 stoichiometric reaction between L3 and Sn[N(SiMe3)2]2 led to the isolation of a dimeric monostannylene 5 having a step-like structure with a Sn2N2 central ring. The reaction of L2 with Sn[N(SiMe3)2]2 underwent an electron transfer reaction ultimately leading to bis(α-iminopyridine) isolation.

Ravindra K. Raut

Papers

Direct coordination of a germanium(II) dicationic center to transition metals

Bis(chlorogermyliumylidene) and its significant role in elusive reductive cyclization.

Role of Ajwa Date Fruit Pulp and Seed in the Management of Diseases through In Vitro and In Silico Analysis

Versatile coordinating abilities of acyclic N4 and N2P2 ligand frameworks in conjunction with Sn[N(SiMe3)2]2

A pyramidal Tin(II) dication and its reactivity studies