From our ab initio investigation, we have improved the understanding of the interaction between Nickel nanoclusters and diatomic molecules, such as CO, NO, and SO, to provide insights into real subnano catalysts.

Cation−π interactions in a set of ruthenophanes [Ru(η 6 -C n H n )(NH 3 ) 3 ] 2+ (n = 16, 18, 20, 22, and 24) (1−9), containing multibridged cyclophanes as ligands, including [2.2]paracyclophane and its multibridged analogs, [2 n ]cyclophanes, are analyzed in terms of SAPT0/TZP and Su−Li EDA analyses. The calculations reveal that the coordination with cation [Ru(NH 3 ) 3 ] 2+ affects the structures of [2 n ]ciclophane ligands, mainly the planarity of the coordinating ring. The EDA results show that the gradual addition of ethano bridges in [2 n ]cyclophanes tends to strengthen the cation−π interaction between [Ru(NH 3 ) 3 ] 2+ and [2 n ]cyclophane. Both Su−Li EDA and SAPT0 are in line, suggesting that the cation−π interactions present a predominant covalent character in complexes 1−9.

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This computational experiment presents qualitative molecular orbital (QMO) and computational quantum chemistry exercises of NO, NO+, and NO–. Initially students explore several properties of the target molecules by Lewis diagrams and the QMO theory. Then, they compare qualitative conclusions with EHT and DFT calculations and explore discrepancies from the experimental results, obtained from Internet databases. Next, they investigate how several properties change with increasing basis set and obtain reliable electronic energies by extrapolation to an infinite basis set. This experiment explores not only quantum chemistry calculations, but also the power of qualitative reasoning. Additionally, it also investigates the behavior of some properties with increasing basis set and the accurate energy calculations by the extrapolation to an infinite basis set.

Copaifera species (Fabaceae) comprises approximately 70 species of large trees, from which 16 can be found in Brazil. The oleoresins obtained from their trunk are widely used in Brazilian folk medicine, which display important antitumoral potential. Chemically, these oleoresins are mainly composed of a mixture of sesquiterpenes and diterpenes. In this paper we are describing the isolation and identification of 12 already known terpenes from oleoresins obtained from three different Copaifera species (C. multijuga, C. pubiflora and C. trapezifolia) and 2 novel diterpenes (ent-16-hidroxy-3,13 clerodadien-15,18-dioic acid and ent-labda-5,13-dien-15-oic acid) from C. trapezifolia. Both new compounds were identified by nuclear magnetic resonance (NMR) spectroscopic (1 H and 13 C NMR, correlation 1 H-1 H (COSY), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond correlation (HMBC)) and by high-resolution electrospray ionization mass spectrometry (HR-ESIMS) analyses. The cytotoxic potential of these oleoresins, their main non-volatile compounds and their volatile compound fractions were evaluated against a panel of tumoral (MCF-7, ACP01, A549, HeLa) and normal cell lines (MCF-10A, GM07492-A) through XTT (tetrazolium salt) and SRB (sulforhodamine B) assays. The novel diterpene ent-labda-5,13-dien-15-oic acid displayed relevant cytotoxic effect against most of the cancer cell lines with mean inhibitory concentration (IC 50) values ranging from 3.57 ± 1.12 to 22.56 ± 1.03 µg mL-1 , and a high selectivity level in both assays.

The role of anions in several biochemical processes gives rise to an enormous interest in the identification/exploration of compounds with potential ability to recognize anions. Here, the anthracene–squaramide conjugated compounds,...

The anionic recognition area is applicable in several biological fields. Squaramide derived compounds appear as potential structures for recognize anions. Here, the bond mechanisms between the chloride (Cl–), bromide (Br–)...

Brazilian green and red propolis stand out as commercial products for different medical applications. In this article, we report the antimicrobial activities of the hydroalcoholic extracts of green (EGP) and red (ERP) propolis, as well as guttiferone E plus xanthochymol (8) and oblongifolin B (9) from red propolis, against multidrug‐resistant bacteria (MDRB). We undertook the minimal inhibitory (MIC) and bactericidal (MBC) concentrations, inhibition of biofilm formation (MICB50), catalase, coagulase, DNase, lipase, and hemolysin assays, along with molecular docking simulations. ERP was more effective by displaying MIC and MBC values <100 μg mL−1. Compounds 8 and 9 displayed the lowest MIC values (0.98 to 31.25 μg mL−1) against all tested Gram‐positive MDRB. They also inhibited the biofilm formation of S. aureus (ATCC 43300 and clinical isolate) and S. epidermidis (ATCC 14990 and clinical isolate), with MICB50 values between 1.56 and 6.25 μg mL−1. The molecular docking results indicated that 8 and 9 might interact with the catalase's amino acids. Compounds 8 and 9 have great antimicrobial potential.