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This article discusses the progress made in the enantioselective total synthesis of γ-rubromycin, a Streptomyces antibiotic. The researchers previously reported a successful photoirradiation method using a chiral, non-racemic 1,2-naphthoquinone to produce an enantioenriched spiroacetal. However, in their latest study, they found that the viability of the photochemical reaction depended on the chromophore structure of the quinones. They also observed that the color of the quinones correlated with their reactivity, with yellow or orange quinones being reactive and red or dark red-purple quinones being unreactive. Further studies are being conducted to gain insights into the photoreaction viability and guide substrate design for the synthesis of γ-rubromycin. [Extracted from the article]

We report the enantioselective total syntheses of preussomerins EG1, EG2, and EG3. The key transformation is a stereospecific photochemical reaction involving 1,6‐hydrogen atom transfer to achieve retentive replacement of a C−H with a C−O bond, enabling otherwise‐difficult control of the spiroacetal stereogenic center. [ABSTRACT FROM AUTHOR]

Antifouling properties of PVDF hollow fiber membrane were improved by the addition of a new synthesized zwitterionic copolymer. This copolymer was synthesized using methyl methacrylate and the zwitterionic monomer 3-(methacryloylamino)propyl-dimethyl(3-sulfopropyl) ammonium hydroxide) (MPDSAH). The copolymer was used as additive in the preparation of a poly(vinylidene fluoride) (PVDF) hollow fiber membrane via thermally induced phase separation. With addition of the copolymer, the crystallization temperature and spherulite growth rate of the polymeric solution decreased sharply. Quartz crystal microbalance with dissipation monitoring results showed that bovine serum albumin (BSA) interactions with the prepared PVDF/copolymer film sharply decreased with addition of the synthesized copolymer. BSA filtration results showed that the membrane had higher antifouling resistance than a membrane without the copolymer additive. [ABSTRACT FROM PUBLISHER]

Self-assembly is a powerful technique for the bottom-up construction of discrete, well-defined nanoscale structures. Large multicomponent systems (with more than 50 components) offer mechanistic insights into biological assembly but present daunting synthetic challenges. Here we report the self-assembly of giant M24L48 coordination spheres from 24 palladium ions (M) and 48 curved bridging ligands (L). The structure of this multicomponent system is highly sensitive to the geometry of the bent ligands. Even a slight change in the ligand bend angle critically switches the final structure observed across the entire ensemble of building blocks between M24L48 and M12L24 coordination spheres. The amplification of this small initial difference into an incommensurable difference in the resultant structures is a key mark of emergent behavior. [ABSTRACT FROM AUTHOR]