Structural, Hirshfeld surface and three-dimensional inter-action-energy studies of 1,3,5-triethyl 2-amino-3,5-di-cyano-4,6-bis-(4-fluoro-phen-yl)cyclo-hex-1-ene-1,3,5-tri-carboxyl-ate.

In the title compound, C29H27F2N3O6, which crystallizes in the monoclinic space group P21/c, the cyclo-hexenone ring is puckered and adopts an envelope conformation. The crystal structure features various inter-molecular inter-actions, such as N-H⋯O, C-H⋯N and C-H⋯O. These inter-actions were investigated using Hirshfeld surface analysis and the three-dimensional inter-action energies were calculated using the B3LYP/6-31 G(d,p) energy density model.

Identification of the furanose ring conformations and the factors driving their adoption.

Three groups of furanoses with restricted freedom of rotation on the C3-C4, C2-C3, and C1-C2 bonds, respectively, are presented. Conformational analysis of these furanoses is conducted based on the proton nuclear magnetic resonance (1H NMR) spectroscopy, density functional theory (DFT) calculations, and X-ray analysis. It is shown that the particular group of the presented furanoses is locked in the specific conformation. These are the 1T2-like, the 0E-like, and the 3T4-like conformation, respectively. Characteristic 1H NMR spectra of these three conformations are presented and the factors influencing the conformational preferences of the analyzed furanoses are discussed.

Characterization of a Novel CD4 Mimetic Compound YIR-821 against HIV-1 Clinical Isolates.

Small CD4-mimetic compound (CD4mc), which inhibits the interaction between gp120 with CD4, acts as an entry inhibitor and induces structural changes in the HIV-1 envelope glycoprotein trimer (Env) through its insertion within the Phe43 cavity of gp120. We recently developed YIR-821, a novel CD4mc, that has potent antiviral activity and lower toxicity than the prototype NBD-556. To assess the possibility of clinical application of YIR-821, we tested its antiviral activity using a panel of HIV-1 pseudoviruses from different subtypes. YIR-821 displayed entry inhibitor activity against 53.5% (21/40) of the pseudoviruses tested and enhanced neutralization mediated by coreceptor binding site (CoRBS) antibodies in 50% (16/32) of these. Furthermore, when we assessed the antiviral effects using a panel of pseudoviruses and autologous plasma IgG, enhancement of antibody-mediated neutralization activity was observed for 48% (15/31) of subtype B strains and 51% (28/55) of non-B strains. The direct antiviral activity of YIR-821 as an entry inhibitor was observed in 53% of both subtype B (27/51) and non-B subtype (40/75) pseudoviruses. Enhancement of antibody-dependent cellular cytotoxicity was also observed with YIR-821 for all six selected clinical isolates, as well as for the transmitted/founder (T/F) CH58 virus-infected cells. The sequence diversity in the CD4 binding site as well as other regions, such as the gp120 inner domain layers or gp41, may be involved in the multiple mechanisms related to the sensitive/resistant phenotype of the virus to YIR-821. Our findings may facilitate the clinical application of YIR-821. IMPORTANCE Small CD4-mimetic compound (CD4mc) interacts with the Phe43 cavity and triggers conformational changes, enhancing antibody-mediated neutralization and antibody-dependent cellular cytotoxicity (ADCC). Here, we evaluated the effect of YIR-821, a novel CD4mc, against clinical isolates, including both subtype B and non-B subtype viruses. Our results confirm the desirable properties of YIR-821, which include entry inhibition, enhancement of IgG-neutralization, binding, and ADCC, in addition to low toxicity and long half-life in a rhesus macaque model, that might facilitate the clinical application of this novel CD4mc. Our observation of primary viruses that are resistant to YIR-821 suggests that further development of CD4mcs with different structural properties is required.

Crystal structure and Hirshfeld surface analysis of (RS)-3-hy-droxy-2-{[(3aRS,6RS,7aRS)-2-(4-methyl-phenyl-sulfon-yl)-2,3,3a,6,7,7a-hexa-hydro-3a,6-ep-oxy-1H-isoindol-6-yl]meth-yl}isoindolin-1-one.

The title compound, C24H24N2O5S, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In the central ring systems of both mol-ecules, the tetra-hydro-furan rings adopt envelope conformations, the pyrrolidine rings adopt a twisted-envelope conformation and the six-membered ring is in a boat conformation. In mol-ecules A and B, the nine-membered groups attached to the central ring system are essentially planar (r.m.s. deviations of 0.002 and 0.003 Å, respectively). They form dihedral angles of 64.97 (9) and 56.06 (10)°, respectively, with the phenyl rings. In the crystal, strong inter-molecular O-H⋯O hydrogen bonds and weak inter-molecular C-H⋯O contacts link the mol-ecules, forming a three-dimensional network. In addition weak π-π stacking inter-actions [centroid-to centroid distance = 3.7124 (13) Å] between the pyrrolidine rings of the nine-membered groups of A mol-ecules are observed. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to qu-antify the inter-molecular inter-actions present in the crystal, indicating that the environments of the two mol-ecules are very similar. The most important contributions for the crystal packing are from H⋯H (55.8% for mol-ecule A and 53.5% for mol-ecule B), O⋯H/H⋯O (24.5% for mol-ecule A and 26.3% for mol-ecule B) and C⋯H/H⋯C (12.6% for mol-ecule A and 15.7% for mol-ecule B) inter-actions.

Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-methyl-benzyl-idene)amino]-5-phenylthiazolidin-2-iminium bromide N,N-di-methyl-formamide monosolvate.

In the cation of the title salt, C17H18N3S+·Br-·C3H7NO, the central thia-zolidine ring adopts an envelope conformation with puckering parameters Q(2) = 0.310 (3) Šand φ(2) = 42.2 (6)°. In the crystal, each cation is connected to two anions by N-H⋯ Br hydrogen bonds, forming an R 4 2(8) motif parallel to the (10) plane. van der Waals inter-actions between the cations, anions and N,N-di-methyl-formamide mol-ecules further stabilize the crystal structure in three dimensions. The most important contributions to the surface contacts are from H⋯H (55.6%), C⋯H/H⋯C (17.9%) and Br⋯H/H⋯Br (7.0%) inter-actions, as concluded from a Hirshfeld analysis.

Polyfunctional Fc Dependent Activity of Antibodies to Native Trimeric Envelope in HIV Elite Controllers.

Antibody dependent (AD) functions such as AD cellular cytotoxicity (ADCC) were associated with lower viral load (VL) in untreated HIV progressors and protection from HIV infection in the modestly protective RV144 HIV vaccine trial. Target cells used to measure ADCC, AD complement deposition (ADCD), and AD cellular trogocytosis (ADCT) have been either HIV envelope (Env) gp120-coated CEM.NKr.CCR5 cells or HIV infected cell cultures. In HIV infected cell cultures, uninfected bystander cells take up gp120 shed from infected cells. Both gp120-coated and gp120+ bystander cells expose CD4 induced (CD4i) epitopes, which are normally hidden in native trimeric Env expressed by genuinely HIV infected cells since Nef and Vpu downmodulate cell surface CD4. Antibody dependent assays using either of these target cells probe for CD4i Abs that are abundant in HIV+ plasma but that do not recognize HIV-infected cells. Here, we examined ADCC, ADCD, and ADCT functions using a target cell line, sorted HIV-infected cell line cells, whose HIV infection frequency nears 100% and that expresses HIV Env in a native trimeric closed conformation. Using sorted HIV-infected cells (siCEM) as targets, we probed the binding and AD functions of anti-gp120/Env Abs in plasma from HIV-infected untreated progressor (UTP, n = 18) and treated (TP, n = 24) subjects, compared to that in Elite controllers (EC, n = 37) and Viral Controllers (VC, n = 16), which are rare subsets of HIV-infected individuals who maintain undetectable or low VL, respectively, without treatment. Gp120-coated beads were used to measure AD cellular phagocytosis. Equivalent concentrations of input IgG in plasma from UTPs, ECs, and VCs supported higher levels of all AD functions tested than plasma from TPs. When AD activities were normalized to the concentration of anti-gp120/Env-specific Abs, between-group differences largely disappeared. This finding suggests that the anti-gp120/Env Abs concentrations and not their potency determined AD functional levels in these assays. Elite controllers did differ from the other groups by having AD functions that were highly polyfunctional and highly correlated with each other. PCR measurement of HIV reservoir size showed that ADCC activity was higher in ECs and VCs with a reservoir size below the limit of detection compared to those having a measurable HIV reservoir size.

Crystal structure and Hirshfeld surface analysis of 6-benzoyl-3,5-di-phenyl-cyclo-hex-2-en-1-one.

In the title compound, C25H20O2, the central cyclo-hexenone ring adopts an envelope conformation. The mean plane of the cyclo-hexenone ring makes dihedral angles of 87.66 (11) and 23.76 (12)°, respectively, with the two attached phenyl rings, while it is inclined by 69.55 (11)° to the phenyl ring of the benzoyl group. In the crystal, the mol-ecules are linked by C-H⋯O and C-H⋯π inter-actions, forming a three-dimensional network.

Crystal structure and Hirshfeld surface analysis of (E)-3-(benzyl-idene-amino)-5-phenyl-thia-zolidin-2-iminium bromide.

The central thia-zolidine ring of the title salt, C16H16N3S+·Br-, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N-H⋯Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (46.4%), C⋯H/H⋯C (18.6%) and H⋯Br/Br⋯H (17.5%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 3,3',3''-[(1,3,5-triazine-2,4,6-tri-yl)tris-(-oxy)]tris-(5,5-di-methyl-cyclo-hex-2-en-1-one).

The three cyclo-hexenone rings of the title compound, C27H33N3O6, adopt slightly distorted envelope conformations, with the C atom bearing two methyl groups as the flap atom in each case. These cyclo-hexenone mean planes form dihedral angles of 87.41 (11), 70.73 (11) and 70.47 (11)° with the 1,3,5-triazine ring, while the dihedral angle between the cyclo-hexenone mean planes are 57.52 (12), 23.75 (12) and 53.21 (12)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming a three-dimensional network.

Crystal structure of 2-benzyl-amino-4-(4-bromo-phen-yl)-6,7-di-hydro-5H-cyclo-penta-[b]pyridine-3-carbo-nitrile.

In the title compound C22H18BrN3, the cyclo-pentane ring adopts an envelope conformation with the central methyl-ene C atom as the flap. The dihedral angles between the central pyridine ring and the pendant benzyl and and bromo-benzene rings are 82.65 (1) and 47.23 (1)°, respectively. In the crystal, inversion dimers linked by pairs of N-H⋯Nn (n = nitrile) hydrogen bonds generate R 2 (2)(12) loops. These dimers are linked by weak π-π inter-actions [centroid-centroid distance = 3.7713 (14) Å] into a layered structure.