Crystal structure of (S)-N-benzyl-1,2,3,4-tetrahydroisoquinoline-3-carboxamide, C17H20N2O2

C17H20N2O2, orthorhombic, P212121 (no. 19), a = 7.1759(1) Å, b = 13.2258(2) Å, c = 15.6553(3) Å, V = 1485.8 Å3, Z = 4, Rgt(F) = 0.0283, wRref(F2) = 0.0797, T = 173 K.

Anticancer activity of ruthenium(II) arene complexes bearing 1,2,3,4-tetrahydroisoquinoline amino alcohol ligands

Ruthenium complexes offer potential reduced toxicity compared to current platinum anticancer drugs. 1,2,3,4-tetrahydrisoquinoline amino alcohol ligands were synthesised, characterised and coordinated to an organometallic Ru(II) centre. These complexes were evaluated for activity against the cancer cell lines MCF-7, A549 and MDA-MB-231 as well as for toxicity in the normal cell line MDBK. They were observed to be moderately active against only the MCF-7 cells with the best IC₅₀ value of 34 μM for the cis-diastereomeric complex C4. They also displayed excellent selectivity by being relatively inactive against the normal MDBK cell line with SI values ranging from 2.3 to 7.4.

{2-[(1,3-Benzo-thia-zol-2-yl)meth-oxy]-5-fluoro-phen-yl}(4-chloro-phen-yl)methanone

The asymmetric unit of the title compound, C₂₁H₁₃ClFNO₂S, contains two independent mol­ecules with similar conformations. In the mol­ecules, the thia­zole ring is essentially planar [maximum atomic deviations = 0.014 (4) and 0.023 (5) Å] and is oriented with respect to the fluoro­phenyl ring and chloro­phenyl rings at 9.96 (18) and 70.39 (18)° in one mol­ecule and at 7.50 (18) and 68.43 (18)° in the other; the dihedral angles between the fluoro­phenyl and chloro­phenyl rings are 64.9 (2) and 64.6 (2)°, respectively. Inter­molecular C—H⋯O and C—H⋯F hydrogen bonds stabilize the three-dimensional supra­molecular architecture. Weak C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.877 (3) Å] lead to a criss-cross mol­ecular packing along the c axis.

[2-(1,3-Benzothia-zol-2-ylmeth-oxy)-5-bromo-phen-yl](4-chloro-phen-yl)methanone

In the title compound, C21H13BrClNO2S, the dihedral angle between the planes of the benzothia-zole and chloro-phenyl-methanone groups is 71.34 (6)°. In the crystal, weak C-H⋯N hydrogen bonds lead to dimer formation, whereas Br⋯Cl short contacts [3.4966 (11) Å] form infinite chains along the a-axis direction. Further, the C-H⋯O, C-H⋯π and π-π [centroid-centroid distance = 3.865 (2) Å] inter-actions stabilize the three-dimensional network.

Methyl 2-(2,3,5-trimethyl-1,1-dioxo-2H-1λ6,2,6-thiadiazin-4-yl)benzoate

There are two mol­ecules, A and B, in the asymmetric unit of the title compound, C₁₄H₁₆N₂O₄S, which is the first example reported in this family of compounds in which the Nsp³ atom of the thia­diazine ring is methyl­ated. The thia­diazine rings adopt shallow envelope conformations, with the S atoms displaced by 0.319 (12) and 0.182 (12) Å from the mean planes of the other ring atoms in mol­ecules A and B, respectively. The dihedral angles between the thia­diazine mean planes (excluding S) and the attached benzene rings are 86.8 (3) and 86.7 (3)° for mol­ecules A and B, respectively.

2-(3,5-Dimethyl-1,1-dioxo-2H-1λ6,2,6-thiadiazin-4-yl)benzoic acid

In the title mol­ecule, C₁₂H₁₂N₂O₄S, the S atom of the thia­diazine ring deviates by 0.5104 (4) Å from the mean plane of the other five atoms [largest deviation = 0.0623 (15) Å] giving a slightly distorted sofa conformation. The carb­oxy H atom was refined as disordered over two sets of sites with refined occupancies of 0.58 (2) and 0.48 (2). This corresponds to rotational disorder of the C=O and O—H groups about the attached C—C bond. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds connect the mol­ecules into chains along [110].

(2-(Benzo[d]thia-zol-2yl-meth-oxy)-5-chloro-phen-yl)(phen-yl)methanone

In the title compound, C₂₁H₁₄ClNO₂S, the dihedral angle between the benzothia­zole and diphenyl methanone groups is 68.6 (2)°. The crystal structure consists of dimeric units generated by C—H⋯N bonds, further linked by C—H⋯O bonds and C—H⋯π and π–π inter­actions [centroid–centroiddistance = 3.856 (2) Å], which lead to a criss-cross assembly parallel to (001).

(S)-4-tert-Butyl-2-(1,2,3,4-tetrahydroisoquinolin-3-yl)-1,3-thiazole

In the title compound, C₁₆H₂₀N₂S, a potential tetra­hydro­isoquinoline (TIQ) thia­zole ligand, the N-containing six-membered ring of the TIQ unit adopts a half-chair conformation. There are four mol­ecules in the asymmetric unit. No classical hydrogen bonds or π–π inter­actions were found in the crystal structure.

Synthesis, screening and computational investigation of pentacycloundecane-peptoids as potent CSA-HIV PR inhibitors

Herein, we present the first pentacycloundecane (PCU) diol peptoid derived HIV protease inhibitors with IC(50) values ranging from 6.5 to 0.075 μM. Five derivatives were synthesized in an attempt to understand the structure activity relationship of this class of compounds for HIV protease inhibition. NMR spectroscopy (new Efficient Adiabatic Symmetrized Rotating Overhauser Effect Spectroscopy, EASY-ROESY) was employed to determine the predominant conformation of the active compound. In this study docking studies and MD simulations provided insight into the binding theme of this class of peptoid inhibitors to the CSA-HIV PR active site. Conserved and stable hydrogen bonding between the hydroxyl groups of the inhibitors and the active site Asp25/Asp25' residues were observed from the docking and along the MD trajectories.

Ethyl 2-(3,5-dimethyl-1,1-dioxo-2H-1λ6,2,6-thiadiazin-4-yl)benzoate

In the title compound, C₁₄H₁₆N₂O₄S, the thia­diazine ring is in a half-boat conformation. The aromatic ring deviates from the plane of this moiety at an angle of 74.6 (2)°. The structure displays inter­molecular N—H⋯O hydrogen bonding [N⋯O = 2.8157 (16) Å], creating ribbons along the [010] axis. There are also weak C—H⋯O inter­actions in the crystal but no π–π stacking.

Molecular modeling of T. rangeli, T. brucei gambiense, and T. evansi sialidases in complex with the DANA inhibitor

Trypanosomal (trans-) sialidases are enzymes that catalyze the transfer of sialic acid residues between host and parasite glycoconjugates. Herein, we have used homology modeling to construct the 3D structures of sialidases from Trypanosoma brucei and Trypanosoma evansi. Hybrid quantum mechanical/molecular mechanical molecular dynamics simulations were used to determine the interaction energy between the 2-deoxy-2,3-didehydro-N-acetylneuraminic acid inhibitor and the three sialidases studied here. Our results suggest that the two constructed enzymes share the same basic fold motive of the Trypanosoma rangeli crystallographic structure. In addition, quantum mechanical/molecular mechanical molecular dynamics simulations show that the 2-deoxy-2,3-didehydro-N-acetylneuraminic acid inhibitor forms a stronger complex with Trypanosoma rangeli than with Trypanosoma brucei and Trypanosoma evansi sialidases. Finally, the interaction energy by residues shows that the arginine triad plays a decisive role to complex 2-deoxy-2,3-didehydro-N-acetylneuraminic acid with the enzyme through hydrogen bonding.