New azafluorenones with cytotoxic and carbonic anhydrase inhibitory properties: 2-Aryl-4-(4-hydroxyphenyl)-5H-indeno[1,2-b]pyridin-5-ones

New azafluorenones, 2-aryl-4-(4-hydroxyphenyl)-5H-indeno[1,2-b]pyridin-5-ones, were prepared to evaluate their cytotoxic/anticancer properties, also their inhibitory effects on hCA I and II isoenzymes. Aryl part was changed as [phenyl (H1), 4-methylphenyl (H2), 4-methoxyphenyl (H3), 4-fluorophenyl (H4), 4-bromophenyl (H5), 4-chlorophenyl (H6), 3-hydroxyphenyl (H7), and 4-hydroxyphenyl (H8)]. The structure of the synthesized compounds was characterized by ¹H NMR, ¹³C NMR and HRMS spectra.Cytotoxicity results of the series pointed out that the compounds H6 (PSE: 28.0) and H5 (PSE: 27.3), with the highest potency selectivity expression (PSE) value, can be considered as leader compounds of the study in designing novel anticancer agents. Additionally, all azafluorenones synthesized showed a good inhibition profile towards hCA I and II isoenzymes in the range of 54.14–73.72 nM and 67.28–76.15 nM, respectively.The compounds H5 and H6 can be considered for further designs with their cytotoxic and CA inhibitory profiles.     

Synthesis and biological evaluation of some new mono Mannich bases with piperazines as possible anticancer agents and carbonic anhydrase inhibitors

New mono Mannich bases, (2-(4-hydroxy-3-((4-substituephenylpiperazin-1-yl)methyl)benzylidene)-2,3-dihydro-1H-inden-1-one), were prepared to evaluate their cytotoxic/anticancer properties and also their inhibitory effects on human carbonic anhydrase I and II isoenzymes (hCA I and II). Amine part was changed as [N-phenylpiperazine (1), N-benzylpiperazine (2), 1-(2-fluorophenyl)piperazine (3), 1-(4-fluorophenyl)piperazine (4), 1-(2-methoxyphenyl)piperazine (5)]. The structure of the synthesized compounds was characterized by ¹H NMR, ¹³C NMR and HRMS spectra. Cytotoxicity results of the series pointed out that the compound 4 had the highest tumor selectivity value (TS: 59.4) possibly by inducing necrotic cell death in series. Additionally, all compounds synthesized showed a good inhibition profile towards hCA I and II isoenzymes with the Ki values between 29.6 and 58.4 nM and 38.1–69.7 nM, respectively. These values were lower than the reference compound AZA. However, it seems that the compounds 4 and 2 can be considered as lead compounds of CA studies with the lowest Ki values in series for further designs.     

DNA-binding,enzyme inhibition,and photochemical properties of chalcone-containing metallophthalocyanine compounds

In this study, two novel phthalocyanine complexes were synthesized using their corresponding metal salts and 4-(4-(3-(2,4,5-trimethoxyphenyl)acryloyl)phenoxy)phthalo-nitrile as chalcone ligand (4), which was prepared from the reaction of 4-nitrophthalonitrile with 4-hydroxyphenyl-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (3). These metallophthalocyanines showed good solubility in organic solvents such as CDCl₃, DCM, THF, DMF, and DMSO. The novel phthalocyanine compounds 4a (Pc-Zn) and 4b (Pc-Co) were characterized using their UV–vis, FT-IR, ¹H NMR, ¹³C NMR, and MALDI-TOF mass spectra and elemental analysis. Then the DNA-binding and xanthine oxidase and carbonic anhydrase-I inhibition properties of compounds 4a and 4b were investigated. Photochemical properties (such as singlet oxygen generation and photodegradation) of this novel chalcone phthalocyanine (4a) were determined in dimethyl sulfoxide (DMSO).     

Pyran-2-one derivatives from Croton crassifolius as potent apoptosis inducers in HepG2 cells via p53-mediated Ras/Raf/ERK pathway

Chemical investigation of the roots of Croton crassifolius led to the isolation of five pyran-2-one derivatives, including two brand new compounds (1–2), one new natural product (3) and two known compounds (4–5). Their structures and absolute configurations were established by spectroscopic analyses as well as comparison between the calculated optical rotation (OR) values with the experimental data. Interestingly, the new compound 1 showed an unusual negative chemical shift at H-11. It is well known that negative chemical shift values of ¹H NMR spectrum are extremely rare in natural products. Such a negative chemical shift of ¹H NMR spectrum was reproduced by density functional theory (DFT) calculations and explained by the shielding effect from the pyran-2-one ring over the hydrogen atom in the 3D conformations. Then, MTT assay was applied to evaluate the cytotoxicity of the isolated compounds (1–5) against two liver cancer cell lines (HepG2 and MHCC97H). The results suggested that compound 1 displayed the highest cytotoxicity with an IC₅₀ value of 9.8 μM against HepG2 cells. Moreover, there was no obvious cytotoxicity of compounds 1–5 on normal liver cell line LO2. Furthermore, the mechanism of apoptosis induction in compound 1-treated HepG2 cells was investigated. The results showed that compound 1 could induce apoptosis via p53-mediated Ras/Raf/ERK suppression in HepG2 cells.     

Synthesis,identification and in vitro biological evaluation of some novel quinoline incorporated 1,3-thiazinan-4-one derivatives

The present study describes the synthesis of two new series of 3-hydroxy-N-(4-oxo-2-phenyl-1,3-thiazinan-3-yl)-8-(trifluoromethyl)quinoline-2-carboxamide derivatives (4a–j) and 3-((7-chloroquinolin-4-ylamino)methyl)-2-phenyl-1,3-thiazinan-4-one derivatives (5a–7j). All the compounds were synthesized in moderate to good yield by one-pot three component cyclo-condensation reaction. The newly synthesized compounds were characterized by FT-IR, ¹H, ¹³C NMR and elemental analysis. The compounds were screened for their in vitro antibacterial activity against a panel of pathogenic bacterial strains, antitubercular activity against Mycobacterium tuberculosis H₃₇Rv and also for their in vitro antimalarial activity against Plasmodium falciparum. Among the synthesized compounds two of them (4f and 5f) showed excellent antibacterial activity against C. tetani at 15.6 μg/mL. Some of them exhibited excellent antitubercular (4f & 5f) and good antimalarial (4f, 5f & 6f) activity compared with the first line drugs.     

Novel pyrazole integrated 1,3,4-oxadiazoles: Synthesis,characterization and antimicrobial evaluation

A novel series of 2-(5-methyl-1,3-diphenyl-1H-pyrazol-4-yl)-5-phenyl-1,3,4-oxadiazoles 7(a–m) were synthesized either by cyclization of N′-benzoyl-5-methyl-1,3-diphenyl-1H-pyrazole-4-carbohydrazide 4a using POCl₃ at 120 °C or by oxidative cyclization of hydrazones derived from various arylaldehyde and (E)-N′-benzylidene-5-methyl-1,3-diphenyl-1H-pyrazole-4-carbohydrazide 5(a–d) using chloramine-T as oxidant. Newly synthesized compounds were characterized by analytical and spectral (IR, ¹H NMR, ¹³C NMR and LC–MS) methods. The synthesized compounds were evaluated for their antimicrobial activity and were compared with standard drugs. The compounds demonstrated potent to weak antimicrobial activity. Among the synthesized compounds, compound 7m emerged as an effective antimicrobial agent, while compounds 7d, 7f, 7i and 7l showed good to moderate activity. The minimum inhibitory concentration of the compounds was in the range of 20–50 μg mL⁻¹ against bacteria and 25–55 μg mL⁻¹ against fungi. The title compounds represent a novel class of potent antimicrobial agents.     

Novel metabolites from the roots of Cadaba natalensis

From an extract of the roots of Cadaba natalensis Sond. the novel macrocyclic dibenzo-diazacyclododecanedione 1 was isolated together with (S)-2-ethyl-2-methyloxazolidin-5-one (2a). In addition, the five known compounds were obtained. Of these, (R)-5-ethyl-5-methyloxazolidin-2-one (3) is reported as a natural product for the first time. The structures of the isolated compounds were elucidated by analysis of the spectral data, 1D NMR (¹H, ¹³C, and DEPT), 2D NMR (COSY, HMQC, HMBC, and NOESY), and HRESIMS, as well as by the comparison with previously reported data.     

Ultrasound mediated efficient synthesis of new 4-oxoquinazolin-3(4H)-yl)furan-2-carboxamides as potent tyrosinase inhibitors: Mechanistic approach through chemoinformatics and molecular docking studies

We have carried out the synthesis of new 4-oxoquinazolin-3(4H)-yl)furan-2-carboxamide derivatives by the reaction between isatoic anhydride, 2-furoic hydrazide and substituted salicylaldehydes in ethanol: water (5:5 v/v) solvent system using p-TSA as a catalyst under ultrasound irradiation at room temperature. The structures of newly synthesized compounds were confirmed through spectral techniques such as IR, ¹H NMR, ¹³C NMR, and LCMS. The important features of this protocol include simple and easy workup procedure, reaction carried out at ambient temperature, use of ultrasound and high yield of oxoquinazolin-3(4H)-yl)furan-2-carboxamides in short reaction time. The synthesized compounds 4a–4j were screened against tyrosinase enzyme and all these compounds found to be potent inhibitors with much lower IC₅₀ value of 0.028 ± 0.016 to 1.775 ± 0.947 µM than the standard kojic acid (16.832 ± 1.162 µM). The kinetics mechanism for compound 4e was analyzed by Lineweaver-Burk plots which revealed that compound inhibited tyrosinase non-competitively by forming an enzyme-inhibitor complex. Along with this all the synthesized compounds (4a–4j) were scanned for their DPPH free radical scavenging ability. The outputs received through in vitro and in silico analysis are coherent to the each other with good binding energy values (kcal/mol) posed by synthesized ligands.     

Synthesis,Antimicrobial and Antioxidant Activity of Pyrazole Based Sulfonamide Derivatives

A series of new sulfonamides have been synthesized from Ampyrone with different benzene sulfonyl chlorides to yield the N-1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) benzenesulfonamides (4a–e). All synthesized compounds were characterized on the basis of FTIR, ¹H NMR, and ¹³C NMR, and also by the aid of mass spectral data. Further, all synthesized compounds have studied for their in vitro antimicrobial activities against selected bacterial as well as fungal strains by the agar well diffusion method. Free radical scavenging activity has been investigated by using DPPH method. Among all the synthesized compounds, 4b, 4d, and 4e exhibited significant antimicrobial and antioxidant activities.     

Rational design,synthesis and anti-proliferative evaluation of novel benzosuberone tethered with hydrazide–hydrazones

Two different series of novel analogues of benzosuberones (5a–m and 9a–w) tethered with hydrazone–hydrazides (functional group alterations: Head group to Tail group and vice versa) have been synthesized by the reaction of appropriate aldehydes with substituted hydrazides in excellent yields (87–94%) and their structures were confirmed by ¹H NMR, ¹³C NMR, ESI-MS and HRMS. The newly synthesized compounds were evaluated for anti-proliferative activity against different human cancer cell lines (HeLa, MDA MB 231, MIAPACA and IMR32). Among the synthesized compounds, six compounds 5a, 5b, 5d, 5e, 5f and 9v exhibited potent anti-proliferative activity with GI₅₀ values less than 0.01 μM against MIAPACA, MDA-MB-231 and IMR32 human cancer cell lines.     

Exploration of antimicrobial and antioxidant potential of newly synthesized 2,3-disubstituted quinazoline-4(3H)-ones

A series of 2-(chloromethyl)-3-(4-methyl-6-oxo-5-[(E)-phenyldiazenyl]-2-thioxo-5,6-dihydropyrimidine-1(2H)-yl)quinazoline-4(3H)-ones 9a-j was synthesized by treating 2-(chloroacetyl)amino benzoic acid with 3-amino-6-methyl-5-[(E)-phenyldiazenyl]-2-thioxo-2,5-dihydropyrimidine-4(3H)-one 8a-j and was screened for in vitro antibacterial activities against a representative panel of Gram-positive and Gram-negative bacteria. The compounds were synthesized in excellent yields and the structures were corroborated on the basis of IR, ¹H NMR, Mass and elemental analysis data. All the synthesized compounds elicited the potent inhibitory action against all the tested bacterial stains. Furthermore, in order to explore the antioxidant potential of newly synthesized compounds, the free radical scavenging activity measurement were performed by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay method. It is revealed from the antioxidant screening results that the compounds 9c and f manifested profound antioxidant potential.     

Synthesis of some novel orcinol based coumarin triazole hybrids with capabilities to inhibit RANKL-induced osteoclastogenesis through NF-κB signaling pathway

A total of twenty-two novel coumarin triazole hybrids (4a-4k and 6a-6k) were synthesized from orcinol in good to excellent yields of 70–94%. The structures of all the synthesized compounds were elucidated by spectroscopic techniques such as ¹H NMR, ¹³C NMR, and HRMS. The anti-inflammatory potential of synthesized compounds was investigated against the proinflammatory cytokine, TNF-α on U937 cell line and compounds 4d, 4j, and 6j were found to exhibit promising anti-inflammatory activity. These three compounds were further screened against TNF-α on LPS-stimulated RAW 264.7 cells, which confirm their anti-inflammatory potential. Furthermore, the above said active compounds were tested for their inhibitory effect on RANKL-induced osteoclastogenesis in RAW 264.7 cells by using tartrate resistant acid phosphatase (TRAP) staining assay at 10 µM. Molecular mechanism studies demonstrated that compound 4d exhibited dose dependent inhibition of RANKL-induced osteoclastogenesis by suppression of the NF-kB pathway. Thus, compound 4d is a promising candidate for further optimization to develop as a potent anti-osteoporotic agent.     

Synthesis of novel 5-amino-1,3,4-thiadiazole-2-sulfonamide containing acridine sulfonamide/carboxamide compounds and investigation of their inhibition effects on human carbonic anhydrase I,II, IV and VII

Herein, we report that acridine intermediates 5 were obtained from the reduction of nitro acridine derivatives 4, which were synthesized via condensation of dimedone, p-nitrobenzaldehyde with 4-amino-N-(5-sulfamoyl-1,3,4-thiadiazol-2-yl)benzamide, respectively. Then acridine sulfonamide/carboxamide (7a–i) compounds were synthesized by reaction of amino acridine 5 with sulfonyl chlorides and carbamoyl chlorides. The new compounds were characterized by melting points, FT-IR, ¹H NMR, ¹³C NMR and HRMS analyzes. The evaluation of in vitro test of the synthesized compounds against hCA I, II, IV and VII showed that some of them are potent inhibitors. Among them, compound 7e showed the most potent activity against hCA II with a K_I of 7.9 nM.     

Design and synthesis of positional isomers of 5 and 6-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles as possible antimicrobial and antitubercular agents

In this Letter, we report the structure–activity relationship (SAR) studies on series of positional isomers of 5(6)-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles derivatives 7(a–j) and 8(a–j) synthesized in good yields and characterized by ¹H NMR, ¹³C NMR and mass spectral analyses. The crystal structure of 7a was evidenced by X-ray diffraction study. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), antifungal activity against Candida albicans, Aspergillus flavus and Rhizopus sp. and antitubercular activity against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis, Mycobacterium fortuitum and MDR-TB strains. The synthesized compounds displayed interesting antimicrobial activity. The compounds 7b, 7e and 7h displayed significant activity against Mycobacterium tuberculosis H37Rv strain.     

1,4-Dihydroquinazolin-3(2H)-yl benzamide derivatives as anti-inflammatory and analgesic agents with an improved gastric profile: Design,synthesis, COX-1/2 inhibitory activity and molecular docking study

The design and synthesis of a new series of 1,4-dihydroquinazolin-3(2H)-yl benzamide derivatives (4a–o) as anti-inflammatory and analgesic agents and COX-1/2 inhibitors are reported. The target compounds (4a–o) were synthesized using a two-step scheme, and their chemical structures were confirmed with ¹H NMR, ¹³C NMR, and mass spectra and elemental analysis. Compounds 4b, 4d, 4h, 4l, 4n and 4o showed the best in vitro COX-2 inhibitory activity (IC₅₀ 0.04–0.07 μM), which was nearly the same as that of the reference drug celecoxib (IC₅₀ 0.049 μM), but had a lower selectivity index, as dictated in our target design. In the in vivo anti-inflammatory inhibition assay, compounds 4b, 4c, 4e, 4f, 4m and 4o showed better oedema inhibition percentages, ranging from 38.1% to 54.1%, than did diclofenac sodium (37.8%). An in vivo analgesic assay revealed that compounds 4b and 4n had a potential analgesic effect 4- to 21-fold more potent than that of indomethacin and diclofenac sodium. All the tested compounds showed an improved ulcerogenic index when compared to indomethacin. In the synthesized series, compound 4b showed the best biological activity in all the experiments. The docking study results agreed with the in vitro COX inhibition assay results. Moreover, the predicted in silico studies of all the compounds support their potential as drug candidates.     

Synthesis,characterization and antimicrobial activities of novel silver(I) complexes with coumarin substituted N-heterocyclic carbene ligands

Eight new coumarin substituted silver(I) N-heterocyclic carbene (NHC) complexes were synthesized by the interaction of the corresponding imidazolium or benzimidazolium chlorides and Ag₂O in dichloromethane at room temperature. Structures of these complexes were established on the basis of elemental analysis, ¹H NMR, ¹³C NMR, IR and mass spectroscopic techniques. The antimicrobial activities of carbene precursors and silver NHC complexes were tested against standard strains: Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungi Candida albicans and Candida tropicalis. Results showed that all the compounds inhibited the growth of the all bacteria and fungi strains and some complexes performed good activities against different microorganisms. Among all the compounds, the most lipophilic complex bis[1-(4-methylene-6,8-dimethyl-2H-chromen-2-one)-3-(naphthalene-2-ylmethyl)benzimidazol-2-ylidene]silver(I) dichloro argentate (5e) was found out as the most active one.     

Synthesis,characterization, and in vitro antimicrobial activities of 5-alkenyl/hydroxyalkenyl-2-phenylamine-1,3,4-oxadiazoles and thiadiazoles

The long-chain alkenoic acid hydrazides (1a–d) on reaction with phenylisocyanate and phenylthiocyanate gave their corresponding semicarbazides (2a–d) and thiosemicarbazides (4a–d), which on further refluxing with POCl₃ and Ac₂O yielded corresponding 1,3,4-oxadiazoles (3a–d) and thiadiazoles (5a–d), respectively.The structure elucidation of synthesized compounds is based on the elemental analysis and spectral data (IR, ¹H NMR, ¹³C NMR and MS). The synthesized oxadiazoles and thiadiazoles have been screened for antibacterial and antifungal activities. The investigation of antimicrobial screening revealed that compounds 3c, 3d, 5c, 5d and compounds 3b, 5b, showed good antibacterial and antifungal activities, respectively.     

Synthesis,X-ray crystal structure study and antitumoral evaluations of 5,6-disubstituted pyrimidine derivatives

5,6-Disubstituted pyrimidine derivatives (3–20) were prepared by intramolecular cyclization reaction of α-(1-carbamyliminomethylene)-γ-butyrolactone (2) with sodium ethoxide and subsequent chemical transformation of 2-hydroxy group in C-5 side chain as well as lithiation reaction for introduction of acyclic side chain at C-6. All compounds were characterized by ¹H NMR, ¹³C NMR and mass spectra. Structures of compounds 4, 7 and 14 were unambiguously confirmed by X-ray crystal structural analysis. Supramolecular structures of these three compounds differ significantly. Two N–H?O and one C–H?O hydrogen bonds in 4 form three-dimensional network. One O–H?N hydrogen bond and one π?π interaction self-assemble the molecules of 7 into sheets. In supramolecular aggregation of 14, only π?π stacking interactions participate, so forming chains. The compounds were evaluated for their cytostatic activities against human malignant cell lines. Of all tested compounds, 2,4-dimethoxy-5-methoxytritylethylpyrimidine (9) and 2,4-dichloro-5-chloroethylpyrimidine (14) exhibited the most prominent inhibitory effects. Furthermore, compound 14 showed marked activity against human colon carcinoma (IC₅₀ = 0.4 μM).     

Design,synthesis, molecular docking and biological activity evaluation of some novel indole derivatives as potent anticancer active agents and apoptosis inducers

Reaction of 5-morphilinosulfonylisatin (1) with acetophenones (2a–e) afforded 3-hydroxy-3-substituted-2-oxoindoles 3a-e, when treated with acetic acid the expected 3-phenacylidene-2-oxoindoles 4a-d and 4-hydroxy-5′-(morpholinosulfonyl) spiro [chromene-2, 3′-indolin]-2′-one 6 were obtained. Isatin derivative (1) was stirred with cyano derivatives to produce the arylidines (7a-c), while under reflux condition, it gave pyrrolo[2,3–b]indoles (8, 9). Moreover, istain (1) reacted with pyrazolo-5-one or 3-substituted phenol in presence of malononitrile to afford spiroxindole derivatives (10a,b) and (11a,b). Also, compounds (10a,b) and (11a,b) were obtained through cyclization of (7a) with pyrazolo-5-one or 3-substituted phenol. The obtained compounds were identified by IR, ¹H NMR, ¹³C NMR and elemental analysis. Anticancer activity against three cancer cell lines (HepG-2, HCT-116 and MCF-7) were evaluated using sulforhodamine B assay method. Compounds 4b, 4c, 7a, 7c and 9 showed broad spectrum anticancer activity on the three tested cell lines with IC₅₀ values less than 10 µM. Cell cycle analysis was performed for the most promising derivatives, compounds 4b and 7c arrested HepG-2 cells at G2-M phase, while compounds 7a and 9 accumulated cells at G0-G1 phase, all of them induced apoptosis at priG1 phase in the range of (11.32–19.17%). Additionally compounds 4b, 7a and 9 showed more potent activity against EGFR than Lapatinib, their IC₅₀ values are from 0.019 to 0.026 µM while IC₅₀ of Lapatinib is 0.028 µM. Molecular docking studies were conducted to investigate the binding mode, amino acid interactions and free binding energy of these potent derivatives.