2-Cyclopenten-1-one (2CP), which is a cyclic enone, has been considered an important precursor because of its versatile functionality in the synthesis of natural products and materials for biofuels. Here, we report the adiabatic ionization energy (AIE) and cationic structure of 2CP in the ionic transition between the neutral S0 and the cationic D0 states probed by high-resolution vacuum ultraviolet mass-analyzed threshold ionization (VUV-MATI) spectroscopy. From the 0-0 band position in the VUV-MATI spectrum supported by the VUV-photoionization efficiency curve, the AIE of 2CP was determined to be 9.3477 ± 0.0004 eV (75,395 ± 3 cm-1), which is in good agreement with the reference value but much more accurate. The measured MATI spectrum combined with the Franck-Condon fitting at the B3LYP/cc-pVTZ level revealed that the cationic structure of 2CP is twisted with the C1 symmetry, whereas the neutral 2CP has the CS symmetry.  https://www.selleckchem.com/products/ipilimumab.html  The results indicate that geometrical changes induced by ionization are mainly attributed to the electron removal from the highest occupied molecular orbital, which consists of nonbonding orbitals on the oxygen atom in the carbonyl group interacting with the σ orbitals in the molecular plane of 2CP. Consequently, lowering the C1 symmetry for cationic 2CP led to the promotions of the ring-bending and ring-twisting modes in the MATI spectrum, which correspond to the ring puckering and C═C twisting in the S0 state, respectively.Oligosaccharide natural products have diverse biological activities and represent a potentially important source for drug development. In this study, we focus on the glycosylation pathway in the biosynthesis of saccharomicin A (SA-A), an oligosaccharide antibiotic containing 17 sugar moieties. By extensive gene-knockout studies with comparative metabolic profile analysis, we established a complete pathway in assembling the heptadecasaccharide chain of SA-A, the longest saccharide chain found in natural products.We present herein an unprecedented desymmetrization of meso 1,3-diones by enantioselective intermolecular condensation. Under the catalysis by a chiral phosphoric acid, a range of readily available 1,3-diones undergo reaction with hydrazines to produce cyclic and acyclic keto-hydrazones bearing an all-carbon quaternary center in high efficiency and enantioselectivity. These compounds are also highly versatile for the preparation of multifunctional building blocks and heterocycles in excellent stereoselectivity.To reduce time and cost, virtual ligand screening (VLS) often precedes experimental ligand screening in modern drug discovery. Traditionally, high-resolution structure-based docking approaches rely on experimental structures, while ligand-based approaches need known binders to the target protein and only explore their nearby chemical space. In contrast, our structure-based FINDSITEcomb2.0 approach takes advantage of predicted, low-resolution structures and information from ligands that bind distantly related proteins whose binding sites are similar to the target protein. Using a boosted tree regression machine learning framework, we significantly improved FINDSITEcomb2.0 by integrating ligand fragment scores as encoded by molecular fingerprints with the global ligand similarity scores of FINDSITEcomb2.0. The new approach, FRAGSITE, exploits our observation that ligand fragments, e.g., rings, tend to interact with stereochemically conserved protein subpockets that also occur in evolutionarily unrelated proteint catalyzes the conversion of dihydrofolate to tetrahydrofolate, and the kinase ACVR1, FRAGSITE identified new small-molecule nanomolar binders. Interestingly, one new binder of DHFR is a kinase inhibitor predicted to bind in a new subpocket. For ACVR1, FRAGSITE identified new molecules that have diverse scaffolds and estimated nanomolar to micromolar affinities. Thus, FRAGSITE shows significant improvement over prior state-of-the-art ligand virtual screening approaches. A web server is freely available for academic users at http/sites.gatech.edu/cssb/FRAGSITE.This contribution describes an advanced compartmentalized micellar nanoreactor that possesses a reversible photoresponsive feature and its application toward photoregulating reaction pathways for incompatible tandem catalysis under aqueous conditions. The smart nanoreactor is based on multifunctional amphiphilic poly(2-oxazoline)s and covalently cross-linked with spiropyran upon micelle formation in water. It responds to light irradiation in a wavelength-selective manner switching its morphology as confirmed by dynamic light scattering and cryo-transition electron microscopy. The compartmental structure renders distinct nanoconfinements for two incompatible enantioselective transformations a rhodium-diene complex-catalyzed asymmetric 1,4-addition occurs in the hydrophilic corona, while a Rh-TsDPEN-catalyzed asymmetric transfer hydrogenation proceeds in the hydrophobic core. Control experiments and kinetic studies showed that the gated behavior induced by the phototriggered reversible spiropyran to merocyanine transition in the cross-linking layer is key to discriminate among substrates/reagents during the catalysis. The smart nanoreactor realized photoregulation to direct the reaction pathway to give a multichiral product with high conversions and perfect enantioselectivities in aqueous media. Our SCM catalytic system, on a basic level, mimics the concepts of compartmentalization and responsiveness Nature uses to coordinate thousands of incompatible chemical transformations into streamlined metabolic processes.Synthesizing different types of sequence-controlled copolyesters can enrich the diversity of copolyesters and modify their properties more precisely, but it is still a challenge to synthesize a complicated sequence-controlled copolyester using different hydroxy acids in a living polymerization manner. In this work, a highly regioselective and stereoselective catalytic system was developed to synthesize biorenewable and biodegradable copolyesters of mandelic acid and lactic acid with isotactic-alternating, heterotactic-alternating, and ABAA-type precise and complicated sequences. Because of the regular incorporation of mandelic acid into polylactide, these sequence-controlled copolymers of mandelic acid and lactic acid show higher glass-transition temperatures than polylactide and a random copolymer. A stereocomplexation interaction between two opposite enantiomeric isotactic polymer chains was also discovered in the isotactic-alternating copolymer.