Discovery of a new Bcl-2 inhibitor through synthesis, anticancer activity, docking and MD simulations

A database of 300 compounds was virtually screened and docked against Bcl-2 protein; the stability of the best-formed complex was evaluated through Molecular dynamics, the top ten compounds with the best in-silico complexation affinities were synthesized, and their In-vitro cytotoxic activity was examined. Thiazolidinone (4e) and isoxazoline (4a-d) were evaluated in-silico. For further evaluation and examination, we designed and synthesized from naturally occurring (R)-carvone and characterized it via spectroscopic analysis, as well as tested for their anticancer activities towards human cancer cell lines such as HT-1080 (fibrosarcome cancer), MCF-7 and MDA-MB-231 (breast cancer) and A-549 (lung cancer) by using MTT method with Doxorubicin as standard drug. Among them, compound 4d showed the most promising anticancer activity against HT-1080, A-549, MCF-7, and MDA-MB-231 cell lines with IC50 values of 15.59 ± 3.21 µM; 18.32 ± 2.73 µM; 17.28 ± 0.33 µM and 19.27 ± 2.73 µM respectively.Communicated by Ramaswamy H. Sarma.

Crystal structure, Hirshfeld surface analysis, crystal voids, inter-action energy calculations and energy frameworks and DFT calculations of ethyl 2-cyano-3-(3-hy-droxy-5-methyl-1H-pyrazol-4-yl)-3-phen-yl-propano-ate

The title compound, C16H17N3O3, is racemic as it crystallizes in a centrosymmetric space group (P ), although the trans disposition of substituents about the central C-C bond is established. The five- and six-membered rings are oriented at a dihedral angle of 75.88 (8)°. In the crystal, N-H⋯N hydrogen bonds form chains of mol-ecules extending along the c-axis direction that are connected by inversion-related pairs of O-H⋯N into ribbons. The ribbons are linked by C-H⋯π(ring) inter-actions, forming layers parallel to the ab plane. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (45.9%), H⋯N/N⋯H (23.3%), H⋯C/C⋯H (16.2%) and H⋯O/O⋯H (12.3%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 100.94 Å3 and 13.20%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure, Hirshfeld surface and crystal void analysis, inter-molecular inter-action energies, DFT calculations and energy frameworks of 2H-benzo[b][1,4]thia-zin-3(4H)-one 1,1-dioxide

In the title mol-ecule, C8H7NO3S, the nitro-gen atom has a planar environment, and the thia-zine ring exhibits a screw-boat conformation. In the crystal, corrugated layers of mol-ecules parallel to the ab plane are formed by N-H⋯O and C-H⋯O hydrogen bonds together with C-H⋯π(ring) and S=O⋯π(ring) inter-actions. The layers are connected by additional C-H⋯O hydrogen bonds and π-stacking inter-actions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯O/O⋯H (49.4%), H⋯H (23.0%) and H⋯C/C⋯H (14.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated as 75.4 Å3 and 9.3%. Density functional theory (DFT) computations revealed N-H⋯O and C-H⋯O hydrogen-bonding energies of 43.3, 34.7 and 34.4 kJ mol-1, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the electrostatic energy contribution. Moreover, the DFT-optimized structure at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Synthesis, crystal structure, spectroscopic characterization, DFT calculations, Hirshfeld surface analysis, molecular docking, and molecular dynamics simulation investigations of novel pyrazolopyranopyrimidine derivatives

A series of new pyrazolopyranopyrimidine derivatives (3-9) were synthesized from 5-amino-2,4-dihydro-3-methyl-4-phenylpyrano-[2,3-c]pyrazole-5-carbonitrile (2) by multicomponent reactions (MCR) involving malononitrile, benzaldehyde, and pyrazolone under refluxing ethanol in the presence of piperidine. Compound (2) was then converted to 2-acetylpyrazolopyranopyrimidine (3) through a reaction with acetic anhydride. The deprotection of 3 using ammonium hydroxide in ethanol, leads to 4. Subsequent chlorination of 4 by phosphorus oxychloride affords 5 which was alkylated using methyl iodide and ethyl bromoacetate in DMF, leading to regioisomers 6-9. The products were characterized by spectroscopic techniques (1H and 13C NMR) and confirmed by single crystal X-ray diffraction (XRD) studies for 2, 5, 6, and 9. Moreover, the geometrical parameters, molecular orbital calculations, and spectral data of 2, 5, 6, and 9 were compared by DFT at the B3LYP/6-311G(d,p) level of theory. There is good agreement between the calculated results and the experimental data. The intermolecular contacts for 2, 5, 6, and 9 were studied by Hirshfeld surface analysis. In addition, the molecular docky study was conducted to investigate the binding patterns of 2, 5, 6, and 9 within the binding site of cyclin-dependent kinase 2 (CDK2) and penicillin-binding protein 1 A. After the docking process, molecular dynamics (MD) simulations for 100 ns were performed on CDK2 and PBP 1 A proteins in the complex with 5.Communicated by Ramaswamy H. Sarma.

Combined molecular dynamics simulations and experimental studies of the removal of cationic dyes on the eco-friendly adsorbent of activated carbon decorated montmorillonite Mt@AC

In recent years, the combination of experimental and theoretical study to explain adsorbate/adsorbent interactions has attracted the attention of researchers. In this context, this work aims to study the adsorption of two cationic dyes, namely methylene blue (MB) and crystal violet (CV), on a green adsorbent Montmorillonite@activated carbon (Mt@AC) composite and to explain the adsorption behavior of each dye by the molecular dynamics (MD) simulation method. The eco-friendly nanocomposite Mt@AC is synthesized and characterized by the analysis methods: XRD, FTIR, BET, TGA/DTA, SEM-EDS, EDS-mapping and zeta potential. The experimental results of adsorption equilibrium show that the adsorption of the two dyes is well suited to the Langmuir adsorption model. The maximum adsorption capacity of the two dyes reaches 801.7 mg g^-1 for methylene blue and 1110.8 mg g^-1 for crystal violet. The experimental kinetics data fit well with a pseudo-first order kinetic model for the two dyes with coefficient of determination R ² close to unity, non-linear chi-square χ ² close to zero and lower Root Mean Square Error RMSE (R ² → 1 and χ ² → 0, RMSE lower). Molecular dynamic simulations are run to gain insights on the adsorption process. According to the RDF analysis and interaction energy calculations, the obtained results reveal a better affinity of the CV molecule with both the AC sheet and montmorillonite framework as compared with MB. This finding suggests that CV is adsorbed to a larger extent onto the nanocomposite material which is in good agreement with the adsorption isothermal experiment observations.

Hybrids of thiazolidinone with 1,2,3-triazole derivatives: design, synthesis, biological evaluation, in silico studies, molecular docking, molecular dynamics simulations, and ADMET profiling

A new series of thiazolidinone linked 1,2,3-triazole hybrids 5a-h was designed and synthesized using the copper-catalyzed Huisgen azide-alkyne cycloaddition (CuAAC) between thiazolidinone linked alkyne and aromatic azides. The structures of the newly synthesized compounds were established by NMR (1H and 13C) and HRMS. The targeted thiazolidinone-1,2,3-triazole hybrids were evaluated for their cytotoxic activity against four human cancer cell lines, including fibrosarcoma (HT-1080), lung carcinoma (A-549), and breast carcinoma (MCF-7 and MDA-MB-231) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliun bromide (MTT). The obtained data showed that most of these compounds have moderate anti-proliferative activity with IC50 values between 10.26 ± 0.71 and 53.93 ± 1.20 μM. The compound 5a exhibited higher activity with an IC50 value of 10.26 ± 0.71 µM, compared to 5d with an IC50 value of 11.56 ± 1.98 µM for the HT-1080 and MCF-7 cancer cells line, respectively. Moreover, Annexin-V apoptosis was assessed by flow cytometry for hybrid compounds 5a and 5d against HT-1080 and MCF-7 competitor cell lines, as they increase the level of active caspase 3/7. The experimental results were further confirmed by docking studies followed by molecular dynamic simulations. Both the potent derivatives i.e. 5a and 5d have comparable docking scores and MD simulations results showed that the docked complex of 5a is somewhat more stable than 5d primarily for protein p53. The ADMET profile of both derivatives established their safety zone and drug-like potential.Communicated by Ramaswamy H. Sarma.

Crystal structure, Hirshfeld surface analysis and DFT calculations of ethyl 2-[4-(methylsulfanyl)-1H-pyrazolo[3,4-d]pyrimidin-1-yl]acetate

The asymmetric unit of the title compound, C10H12N4O2S, contains two molecules differing slightly in the orientations of the methyl groups. In the crystal, a sandwich-type structure extending parallel to the ab plane is formed by weak C—H...O and C—H...N hydrogen bonds together with slipped π-stacking interactions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (43.5%), H...O/O...H (17.9%) and H...N/N...H (17.4%) interactions. The molecular structure optimized by density functional theory (DFT) at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. Further calculations include the HOMO–LUMO energies and molecular electrostatic potential (MEP) surfaces.

Crystal structure determination, Hirshfeld surface, crystal void, intermolecular interaction energy analyses, as well as DFT and energy framework calculations of 2-(4-oxo-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)acetic acid

In the title molecule, C7H6N4O3, the bicyclic ring system is planar with the carboxymethyl group inclined by 81.05 (5)° to this plane. In the crystal, corrugated layers parallel to (010) are generated by N—H...O, O—H...N and C—H...O hydrogen-bonding interactions. The layers are associated through C—H...π(ring) interactions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...O/O...H (34.8%), H...N/N...H (19.3%) and H...H (18.1%) interactions. The volume of the crystal voids and the percentage of free space were calculated to be 176.30 Å3 and 10.94%, showing that there is no large cavity in the crystal packing. Computational methods revealed O—H...N, N—H...O and C—H...O hydrogen-bonding energies of 76.3, 55.2, 32.8 and 19.1 kJ mol−1, respectively. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via dispersion energy contributions. Moreover, the optimized molecular structure, using density functional theory (DFT) at the B3LYP/6–311G(d,p) level, was compared with the experimentally determined one. The HOMO–LUMO energy gap was determined and the molecular electrostatic potential (MEP) surface was calculated at the B3LYP/6–31G level to predict sites for electrophilic and nucleophilic attacks.

Crystal structure, Hirshfeld surface analysis and inter-action energy calculation of 1-decyl-2,3-di-hydro-1H-benzimidazol-2-one

The title mol-ecule, C17H26N2O, adopts an L-shaped conformation, with the straight n-decyl chain positioned nearly perpendicular to the di-hydro-benzimidazole moiety. The di-hydro-benzimidazole portion is not quite planar as there is a dihedral angle of 1.20 (6)° between the constituent planes. In the crystal, N-H⋯O hydrogen bonds form inversion dimers, which are connected into the three-dimensional structure by C-H⋯O hydrogen bonds and C-H⋯π(ring) inter-actions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (75.9%), H⋯C/C⋯H (12.5%) and H⋯O/O⋯H (7.0%) inter-actions. Based on computational chemistry using the CE-B3LYP/6-31 G(d,p) energy model, C-H⋯O hydrogen bond energies are -74.9 (for N-H⋯O) and -42.7 (for C-H⋯O) kJ mol-1.

Crystal structure, Hirshfeld surface analysis and DFT studies of 1-benzyl-3-[(1-benzyl-1H-1,2,3-triazol-5-yl)meth-yl]-2,3-di-hydro-1H-1,3-benzo-diazol-2-one monohydrate

In the title mol-ecule, C24H21N5O·H2O, the di-hydro-benzo-diazole moiety is not quite planar, while the whole mol-ecule adopts a U-shaped conformation in which there is a close approach of the two benzyl groups. In the crystal, chains of alternating mol-ecules and lattice water extending along [201] are formed by O-HUncoordW⋯ODhyr and O-HUncoordW⋯NTrz (UncoordW = uncoordinated water, Dhyr = di-hydro and Trz = triazole) hydrogen bonds. The chains are connected into layers parallel to (010) by C-HTrz⋯OUncoordW hydrogen bonds with the di-hydro-benzo-diazole units in adjacent layers inter-calating to form head-to-tail π-stacking [centroid-to-centroid distance = 3.5694 (11) Å] inter-actions between them, which generates the overall three-dimensional structure. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (52.1%), H⋯C/C⋯H (23.8%) and O⋯H/H⋯O (11.2%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of (2Z)-4-benzyl-2-(2,4-di-chloro-benzyl-idene)-2H-1,4-benzo-thia-zin-3(4H)-one

The title compound, C22H15Cl2NOS, contains 1,4-benzo-thia-zine and 2,4-di--chloro-benzyl-idene units, where the di-hydro-thia-zine ring adopts a screw-boat conformation. In the crystal, inter-molecular C-HBnz⋯OThz (Bnz = benzene and Thz = thia-zine) hydrogen bonds form corrugated chains extending along the b-axis direction which are connected into layers parallel to the bc plane by inter-molecular C-HMethy⋯SThz (Methy = methyl-ene) hydrogen bonds, en-closing R 4 4(22) ring motifs. Offset π-stacking inter-actions between 2,4-di--chloro-phenyl rings [centroid-centroid = 3.7701 (8) Å] and π-inter-actions which are associated by C-HBnz⋯π(ring) and C-HDchlphy⋯π(ring) (Dchlphy = 2,4-di-chloro-phen-yl) inter-actions may be effective in the stabilization of the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.1%), H⋯C/C⋯H (27.5%), H⋯Cl/Cl⋯H (20.6%) and O⋯H/H⋯O (7.0%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the C-HBnz⋯OThz and C-HMethy⋯SThz hydrogen-bond energies are 55.0 and 27.1 kJ mol-1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 3-{(2Z)-2-[(2,4-di-chloro-phen-yl)methyl-idene]-3-oxo-3,4-di-hydro-2H-1,4-benzo-thia-zin-4-yl}propane-nitrile

The title compound, C18H12Cl2N2OS, consists of a di-hydro-benzo-thia-zine unit linked by a -CH group to a 2,4-di-chloro-phenyl substituent, and to a propane-nitrile unit is folded along the S⋯N axis and adopts a flattened-boat conformation. The propane-nitrile moiety is nearly perpendicular to the mean plane of the di-hydro-benzo-thia-zine unit. In the crystal, C-HBnz⋯NPrpnit and C-HPrpnit⋯OThz (Bnz = benzene, Prpnit = propane-nitrile and Thz = thia-zine) hydrogen bonds link the mol-ecules into inversion dimers, enclosing R 2 2(16) and R 2 2(12) ring motifs, which are linked into stepped ribbons extending along [110]. The ribbons are linked in pairs by complementary C=O⋯Cl inter-actions. π-π contacts between the benzene and phenyl rings, [centroid-centroid distance = 3.974 (1) Å] may further stabilize the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (23.4%), H⋯Cl/Cl⋯H (19.5%), H⋯C/C⋯H (13.5%), H⋯N/N⋯H (13.3%), C⋯C (10.4%) and H⋯O/O⋯H (5.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that the two independent C-HBnz⋯NPrpnit and C-HPrpnit⋯OThz hydrogen bonds in the crystal impart about the same energy (ca 43 kJ mol-1). Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Crystal structure and Hirshfeld surface analysis of 3,4-dihydro-2-(2,4-dioxo-6-methylpyran-3-ylidene)-4-(4-pyridin-4-yl)-1,5-benzodiazepine

The title compound, C20H17N3O3 [systematic name: 2-(6-methyl-2,4-dioxo-pyran-3-yl-idene)-4-(pyridin-4-yl)-2,3,4,5-tetra-hydro-1H-1,5-benzodiazepine], is built up from a benzodiazepine ring system linked to pyridyl and pendant di-hydro-pyran rings, where the benzene and pyridyl rings are oriented at a dihedral angle of 43.36 (6)°. The pendant di-hydro-pyran ring is rotationally disordered in a 90.899 (3):0.101 (3) ratio with the orientation of each component largely determined by intra-molecular N-HDiazp⋯ODhydp (Diazp = diazepine and Dhydp = di-hydro-pyran) hydrogen bonds. In the crystal, mol-ecules are linked via pairs of weak inter-molecular N-HDiazp⋯ODhydp hydrogen bonds, forming inversion-related dimers with R 2 2(26) ring motifs. The dimers are further connected along the b-axis direction by π-π stacking inter-actions between the pendant di-hydro-pyran and pyridyl rings with centroid-centroid distances of 3.833 (3) Å and a dihedral angle of 14.51 (2)°. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (50.1%), H⋯C/C⋯H (17.7%), H⋯O/O⋯H (16.8%), C⋯C (7.7%) and H⋯N/N⋯H (5.3%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing.

2-Methyl-4-(pyridin-2-yl)-3H-1,5-benzodiazepine

In the title compound, C15H13N3, the seven-membered ring adopts a boat conformation. In the crystal, inversion-related C—H...N hydrogen bonds form dimers, which pack in an alternating fashion.

5-Acetamido-1H-pyrazole-4-carboxamide monohydrate

There are two independent molecules of the title carboxamide compound, C6H8N4O2·H2O, as well as two independent water molecules in the asymmetric unit. The two independent carboxamide molecules differ primarily in the relative orientations of the peripheral methyl and amino groups. Intramolecular N—H...O hydrogen bonds assist in determining the orientations of the acetamido substituents. The three-dimensional crystal packing is directed by a large network of O—H...O, N—H...O, C—H...O and C—H...N hydrogen bonds.

Dichlorido(3,5,5'-trimethyl-1,3'-bi-1H-pyrazole-κN,N)copper(II)

In the title complex, [CuCl₂(C₉H₁₂N₄)], the Cu^II atom exhibits a distorted square-planar coordination geometry involving two chloride ions and two N-atom donors from the bipyrazole ligand. The chelate ring including the Cu^II atom is essentially planar, with a maximum deviation of 0.0181 (17) Å for one of the coordinated N atoms. This plane forms a dihedral angle of 30.75 (6)° with the CuCl₂ plane. In the crystal, each pair of adjacent mol­ecules is linked into a centrosymmetric dimer by N—H⋯Cl hydrogen bonds. The crystal structure is stabilized by inter­molecular C—H⋯N and C—H⋯Cl hydrogen bonds and weak slipped π–π stacking inter­actions between symmetry-related mol­ecules, with an inter­planar separation of 3.439 (19) Å and a centroid–centroid distance of 3.581 (19) Å.

Synthesis and anti-HSV activity of new N1-acyclic C4 and C6-disubstituted pyrazolo[3,4-d]pyrimidine nucleosides

Several N(1)-(2-hydroxyethoxy)methyl, (4-hydroxybutyl) and (2,3-dihydroxy-1-propoxy)methyl-C(4),C(6)-disubstituted-1H-pyrozolo[3,4-d]pyrimidines were synthesized. Some of them were evaluated against herpes simplex virus 1 and 2 replications in E(6)SM cells.

Synthesis and biological evaluation of some alpha-[6-(1'-carbamoylalkylthio)-1 H-pyrazolo[3,4-D]pyrimidin-4-yl]thioalkylcarboxamide acyclonucleosides

The reaction of 1H-pyrazolo[3,4-d]pyrimidin-4,6-dithione 11 with compounds 12a-c produces ethyl alpha-[6-(1'-carboethoxyalkylthio)-1 H-pyrazolo[3,4-d]pyrimidin-4-yl]thioalkylates 13a-c, respectively. These heterocycles were alkylated, separately, with alkylating agents 14, 15, and 16 to afford, predominately, the N(1)-acyclic nucleosides (17-19)a-c, which were deprotected to give the desired products (20-22)a-c. All synthetic compounds were characterized on the basis of their physical and spectroscopic properties. The acyclic nucleosides (20-22)a-c were evaluated for their inhibitory effects against the replication of varicella-zoster virus, human cytomegalovirus and M. tuberculosis. No marked biological activity was found.

Synthesis and antiviral activity of some C2-, C4-, and C6-substituted pyrazolo[3,4-D]pyrimidine acyclonucleosides with the alkylating chains of ACV, HBG, and ISO-DHPG

A useful route to obtain trisubstituted pyrazolo[3,4-d]pyrimidines 14-17 is described. Those later were coupled with the alkylating agents 18-20 as in ACV, HBG, and iso-DHPG to give, after deprotection, the desired acylonucleosides 33-44. Almost all of the new compounds were evaluated for their inhibitory effects against the replication of various DNA viruses in culture.

Synthesis and biological evaluation of some acyclic 4,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidine nucleosides

The chemical synthesis and biological evaluation of some acyclic alpha-[6-(1'-carbamoylalkylthio)-1H-pyrazolo[3,4-d]pyrimidin-4-yl]thioalkylamide nucleosides are described.

Synthesis and biological evaluation of some acyclic alpha-(1H-pyrazolo-[3,4-d]pyrimidin-4-yl)thioalkylamide nucleosides

The chemical synthesis of some acyclic alpha-(1H-pyrazolo[3,4-d]pyrimidin-4-yl)thioalkylamide nucleosides (10-12)a-c is described. The treatment of IH-pyrazolo[3,4-d]pyrimidin-4-thione 1 with compounds 2a-c gave, regioselectively, ethyl alpha-(1H-pyrazolo[3,4-d]pyrimidin-4-yl)thioalkylates 3a-c, respectively. These heterocycles were alkylated, separately, with alkylating agents 4, 5 and 6 to give, regioselectively, the N1-acyclic nucleosides (7-9)a-c which were deprotected to afford the desired products (10-12)a-c. All synthetic compounds were characterized on the basis of their physical and spectroscopic properties. The products (10-12)a-c were evaluated for their inhibitory effects against the replication of HIV-1 (III(B)), HIV-2 (ROD), various DNA viruses, a variety of tumor-cell lines and M. tuberculosis. No marked biological activity was found.

Synthesis and biological activity of some 4-substituted 1-[1-(2,3-dihydroxy-1-propoxy)methyl-1,2,3-triazol-(4 & 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines

Cycloaddition of 7a, b with 6 gave, after separation and deprotection, two regioisomers 10a, b and 11a, b. The deprotected acyclic nucleoside 10a used as the precursor for the preparation of 4-amino (12), 4-methylamino (13), 4-benzylamino (14), 4-methoxy (15) and 4-hydroxy (16) analogues. All acyclic nucleosides were evaluated for their inhibitory effects against HIV-1(IIIB), HIV-2(ROD) in MT-4 cells, for their anti-tumor activity and for their inhibitory effects against Mycobacterium tuberculosis. No marked activity was found.

Synthesis and biological activity of 4-substituted 1-[1-(2-hydroxyethoxy)-methyl-1,2,3-triazol-(4 & 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines

The chemical synthesis of some 4-substituted 1-[1-(2-hydroxyethoxy)-methyl-1,2.3-triazol-(4 and 5)-ylmethyl]-1-H-pyrazolo[3,4-d]pyrimidines 12a,b, 13a,b and 14-23 as acyclic nucleosides is described. Treatment of (2-acetoxyethoxy)methylbromide with sodium azide afforded (2-acetoxyethoxy)methylazide 9. The heterocycles 6a,b were alkylated, separately, with propargyl bromide to obtain. regioselectively, 4-(methyl and benzyl)thio-1-(prop-2-ynyl)-1H-pyrazolo[3,4-d]pyrimidines 7a,b. These N-alkylated products were condensed with compound 9 via a 1,3-dipolar cycloaddition reaction to obtain, after separation and deprotection, 1,4- and 1,5-regioisomers 12a,b and 13a,b. The deprotected acyclic nucleosides 12a and 13a served as precursors for the preparation of 4-amino (14 and 15), 4-methylamino (16 and 17). 4-benzylamino (18 and 19), 4-methoxy (20 and 21) and 4-hydroxy (22 and 23) analogues. Compounds 7a,b and all deprotected acyclic nucleosides were evaluated for their inhibitory effects against the replication of HIV-(IIIB) and HIV-2(ROD) in MT-4 cells and for their anti-tumor activity. No marked activity was found. However, initial evaluation of 6a,b, 7a,b. 12a,b, 13a,b and 14-23 showed that compound 7b has marked activity against M. tuberculosis.

Synthesis and biological evaluation of some 4-substituted 1-[1-(4-hydroxybutyl)-1,2,3-triazol-(4 &5)-ylmethyl]-1H-pyrazolo- 13,4-dipyrimidines

The synthesis of 1-[1-(4-hydroxybutyl)-1,2,3-triazol-(4 and 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines 11a,b, 12a,b and 13-17 as carboacyclic nucleosides is described. The compounds 8a,b were condensed, separately, with compound 7 via 1,3-dipolar cycloaddition reaction to afford, after separation and deprotection. 1,4-regioisomers 11a,b and 1,5-regioisomers 12a,b. The deprotected carboacyclic nucleosides 11a served as precursor for the preparation of 4-amino 13. 4-methylamino 14, 4-benzylamino 15, 4-methoxy 16 and 4-hydroxy 17 analogues. All deprotected carboacyclic nucleosides were evaluated for their inhibitory effects against the replication of HIV-1(III), HIV-2(ROD), various DNA viruses, a variety of tumor-cell lines and tuberculosis. No marked biological activity was found.

Synthesis of some acyclonucleosides alpha-(pyrazolo[3,4-d]pyrimidin-4-ylthio)alkylamides

The synthesis of some acyclic alpha-(pyrazolo[3,4-d]pyrimidin-4-ylthio)alkylamide nucleosides is described.