Anticancer activity, toxicity and pharmacokinetic profile of an indanone derivative

Evaluation of Pyrrolone-Fused Benzosuberene MK2 Inhibitors as Promising Therapeutic Agents for HNSCC: In Vitro Efficacy, In-Vivo Safety, and Pharmacokinetic Profiling

MAPKAPK2/MK2 is well implicated in the progression of Head and Neck Squamous Cell Carcinoma (HNSCC), and potent MK2-inhibitors are required to suppress its activity. Several MK2-inhibitors have been developed in recent years to combat its effects on cancer. However, inadequate solubility, insufficient cellular permeability, systemic toxicity-mediated side effects, and low bioavailability have severely impeded the advancement of MK2-inhibitors to clinical trials. This void necessitates research to develop less toxic and more bioavailable potent MK2-inhibitors in HNSCC. In the present article, we have evaluated the in-vitro efficacy, in-vivo single-dose acute toxicity, and in-vivo pharmacokinetic profiling of recently developed PfBS (pyrrolone-fused benzosuberene) MK2-inhibitor analogues against HNSCC. The PfBS MK2 inhibitor analogues impeded HPV+ and HPV- HNSCC cell proliferation and two-dimensional migration. Moreover, MK2-inhibitors lowered HNSCC cell clonogenic survival in a dose-dependent manner, significantly enhancing radiation-induced cell death via exerting radio-sensitization effects. Furthermore, γ-H2AX immunostaining revealed that PfBS analogues impaired DNA damage repair in HNSCC cells exposed to gamma radiation. In mice, PfBS MK2 inhibitors at 300 mg/kg were well-tolerated without any lethal effects. Pharmacokinetic studies showed that PfBS analogues exhibited rapid absorption (Tmax), adequate plasma concentration above the micromolar level (C0 or Cmax), limited tissue distribution (Vd), and faster elimination from the body (Cl). Overall, this study summarizes in-vitro efficacy, safety, and pharmacokinetics of developed MK2-inhibitors and opens doors for pharmacodynamics and mechanism of action study of most effective leads in HNSCC.

Antiproliferative, apoptotic and anti-inflammatory potential of 5H-benzo[h]thiazolo[2,3-b]quinazoline analogues: Novel series of anticancer compounds

Lung cancer (LC) is the most common cancer in males. As per GLOBOCAN 2020, 8.1 % of deaths and 5.9 % of cases of LC were reported in India. Our laboratory has previously reported the significant anticancer potential of 5H-benzo[h]thiazolo[2,3-b]quinazoline analogues. In this study, we have explored the anticancer potential of 7A {4-(6,7-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazolin-7-yl)phenol} and 9A {7-(4-chlorophenyl)-9-methyl-6,7-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazoline}by using in-vitro and in-vivo models of LC. In this study, we investigated the antiproliferative potential of quinazoline analogues using A549 cell line to identify the best compound of the series. The in-vitro and molecular docking studies revealed 7A and 9A compounds as potential analogues. We also performed acute toxicity study to determine the dose. After that, in-vivo studies using urethane-induced LC in male albino Wistar rats carried out further physiological, biochemical, and morphological evaluation (SEM and H&E) of the lung tissue. We have also evaluated the antioxidant level, inflammatory, and apoptotic marker expressions. 7A and 9A did not demonstrate any signs of acute toxicity. Animals treated with urethane showed a significant upregulation of oxidative stress. However, treatment with 7A and 9A restored antioxidant markers near-normal levels. SEM and H&E staining of the lung tissue demonstrated recovered architecture after treatment with 7A and 9A. Both analogues significantly restore inflammatory markers to normal level and upregulate the intrinsic apoptosis protein expression in the lung tissue. These experimental findings demonstrated the antiproliferative potential of the synthetic analogues 7A and 9A, potentially due to their anti-inflammatory and apoptotic properties.

Discovery of novel tubulin CBSI from the indanone scaffold for the treatment of colorectal cancer

In view of the serious adverse reactions and clinical toxicity of first line therapy 5-fluorouracil and lack of small molecule therapeutics in colorectal cancer chemotherapy, a series of natural scaffold-based 3-arylindanone derivatives (9a-q) were designed, synthesized and evaluated as tubulin polymerization inhibitors targeting the colchicine site. The most potent colchicine binding site inhibitor (CBSI), (R)-9k, exhibited 14-38 times more dominant anti-proliferative activity against three colon cancer cell lines than 5-fluorouracil. Particularly, (R)-9k showed higher selectivity against human normal cells compared with 5-fluorouracil and colchicine, and displayed negligible cardiotoxicity through hERG assessment. Furthermore, the binding of (R)-9k to the colchicine site was strongly supported by EBI competition assay and (R)-9k inhibited more tubulin polymerization than colchicine. Besides, the mechanism of action and binding modes of (R)-9k were verified by molecular dynamics simulations and docking. Therefore, (R)-9k could be regarded as a promising CBSI for colorectal cancer therapy.

Flavone-based dual PARP-Tubulin inhibitor manifesting efficacy against endometrial cancer

Structural tailoring of the flavone framework (position 7) via organopalladium-catalyzed C-C bond formation was attempted in this study. The impact of substituents with varied electronic effects (phenyl ring, position 2 of the benzopyran scaffold) on the antitumor properties was also assessed. Resultantly, the efforts yielded a furyl arm bearing benzopyran possessing a 4-fluoro phenyl ring (position 2) (14) that manifested a magnificent antitumor profile against the Ishikawa cell lines mediated through dual inhibition of PARP and tubulin [(IC50 (PARP1) = 74 nM, IC50 (PARP2) = 109 nM) and tubulin (IC50 = 1.4 µM)]. Further investigations confirmed the ability of 14 to induce apoptosis as well as autophagy and cause cell cycle arrest at the G2/M phase. Overall, the outcome of the study culminated in a tractable dual PARP-tubulin inhibitor endowed with an impressive activity profile against endometrial cancer.

Drug-Delivery Silver Nanoparticles: A New Perspective for Phenindione as an Anticoagulant

Anticoagulants prevent the blood from developing the coagulation process, which is the primary cause of death in thromboembolic illnesses. Phenindione (PID) is a well-known anticoagulant that is rarely employed because it totally prevents coagulation, which can be a life-threatening complication. The goal of the current study is to synthesize drug-loaded Ag NPs to slow down the coagulation process. Methods: A rapid synthesis and stabilization of silver nanoparticles as drug-delivery systems for phenindione (PID) were applied for the first time. Results: Several methods are used to determine the size of the resulting Ag NPs. Additionally, the drug-release capabilities of Ag NPs were established. Density functional theory (DFT) calculations were performed for the first time to indicate the nature of the interaction between PID and nanostructures. DFT findings supported that galactose-loaded nanostructure could be a proper delivery system for phenindione. The drug-loaded Ag NPs were characterized in vitro for their antimicrobial, cytotoxic, and anticoagulant activities, and ex vivo for spasmolytic activity. The obtained data confirmed the drug-release experiments. Drug-loaded Ag NPs showed that prothrombin time (PT, sec) and activated partial thromboplastin time (APTT, sec) are approximately 1.5 times longer than the normal values, while PID itself stopped coagulation at all. This can make the PID-loaded Ag NPs better therapeutic anticoagulants. PID was compared to PID-loaded Ag NPs in antimicrobial, spasmolytic activity, and cytotoxicity. All the experiments confirmed the drug-release results.

2-Pyridin-4-yl-methylene-beta-boswellic Acid-A Potential Candidate for Targeting O6-Methylguanine-DNA Methyltransferase Epi-transcriptional Reprogramming in KRAS G13D-Microsatellite Stable, G12V-Microsatellite Instable Mutant Colon Cancer

PMBA (2-Pyridin-4-yl-methylene-beta-boswellic acid), screened from among the 21 novel series of semisynthetic analogues of β-boswellic acid, is being presented as a lead compound for integrative management of KRAS mutant colorectal cancer (CRC), upon testing and analysis for its anticancerous activity on a panel of NCI-60 cancer cell lines and in vivo models of the disease. PMBA (1.7-29 μM) exhibited potent proliferation inhibition on the cell lines and showed sensitivity in microsatellite instability and microsatellite stable (GSE39582 and GSE92921) subsets of KRAS gene (Kirsten rat sarcoma viral oncogene homolog)-mutated colon cell lines, as revealed via flow cytometry analysis. A considerable decrease in mitogen-activated protein kinase pathway downstream effectors was observed in the treated cell lines via the western blot and STRING (Search tool for the retrieval of interacting genes/proteins) analysis. PMBA was further found to target KRAS at its guanosine diphosphate site. Treatment of the cell lines with PMBA showed significant reduction in MGMT promoter methylation but restored MGMT (O⁶-methylguanine-DNA methyltransferase) messenger ribonucleic acid expression via significant demethylation of the hypermethylated CpG (Cytosine phosphate guanine) sites in the MGMT promoter. A significant decrease in dimethylated H3K9 (Dimethylation of lysine 9 on histone 3) levels in the MGMT promoter in DNA hypo- and hypermethylated HCT-116^G13D and SW-620^G12V cells was observed after treatment. In the MNU (N-methyl-N-nitrosourea)-induced CRC in vivo model, PMBA instillation restricted and repressed polyp formation, suppressed tumor proliferation marker Ki67 (Marker of proliferation), ablated KRAS-associated cytokine signaling, and decreased mortality. Clinical trial data for the parent molecule revealed its effectiveness against the disease, oral bioavailability, and system tolerance. Comprehensively, PMBA represents a new class of KRAS inhibitors having a therapeutic window in the scope of a drug candidate. The findings suggest that the PMBA analogue could inhibit the growth of human CRC in vivo through downregulation of cancer-associated biomarkers as well as reactivate expression of the MGMT gene associated with increased H3K9 acetylation and H3K4 methylation with facilitated transcriptional activation, which might be important in silencing of genes associated with upregulation in the activity of KRAS.

Cyclic Oxime Esters as Deconstructive Bifunctional Reagents for Cyanoalkyl Esterification of 1,6-Enynes

A concise copper catalysis strategy for the addition-cyclization of cyclic oxime esters across 1,6-enynes with high stereoselectivity to generate 1-indanones bearing an all-carbon quaternary center is reported. In this process, single-electron reduction of cyclic oxime esters enables deconstructive carbon-carbon cleavage to provide a key cyanopropyl radical poised for the addition-cyclization. This reaction is redox-neutral, exhibits good functional group compatibility, and features 100% atomic utilization. This process driven by copper catalyst makes readily available cyclic oxime esters as bifunctional reagents to demonstrate convergent synthesis.

Copper/silver co-mediated three-component bicyclization for accessing indeno[1,2-c]azepine-3,6-diones

A new copper/silver-co-mediated three-component bicyclization of benzene-linked 1,6-enynes with ICF2CO2Et with TMSN3 was reported, and used to produce a wide range of hitherto unreported difluorinated tetrahydroindeno[1,2-c]azepine-3,6-diones with moderate to good yields. The mechanistic pathway consists of radical-induced 1,6-addition-cyclization, oxidative addition, reductive elimination, nitrene insertion and N-O cleavage, resulting in continuous multiple bond-forming events including C-C and C-N bonds to build up a 6/5/7 tricyclic framework.

Tamarix articulata Inhibits Cell Proliferation, Promotes Cell Death Mechanisms and Triggers G0/G1 Cell Cycle Arrest in Hepatocellular Carcinoma Cells

RESEARCH BACKGROUND

From ancient times plants have been used for medicinal purposes against various ailments. In the modern era, plants are a major source of drugs and are an appealing drug candidate for the anticancer therapeutics against various molecular targets. Here we tested methanolic extract of dry leaves of Tamarix articulata for anticancer activity against a panel of hepatocellular carcinoma cells.

EXPERIMENTAL APPROACH

Cell viability of hepatocellular carcinoma cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after a dose-dependent treatment with the extract of T. articulata. Phase-contrast microscopy and 4՛,6-diamidino-2-phenylindole (DAPI) staining served to analyse cellular and nuclear morphology. Immunoblotting was performed to determine the expression of proteins associated with autophagy, apoptosis and cell cycle. However, flow cytometry was used for the quantification of apoptotic cells and the analysis of cells in different phases of the cycle after the treatment with various doses of T. articulata. Additionally, acridine orange staining and 2՛,7՛-dichlorofluorescein diacetate (DCFH-DA) dye were used to analyse the quantification of autophagosomes and reactive oxygen species.

RESULTS AND CONCLUSION

Our results demonstrate that T. articulata methanolic extract exhibits promising antiproliferative activity with IC50 values (271.1±4.4), (298.3±7.1) and (336.7±6.1) µg/mL against hepatocellular carcinoma HepG2, Huh7D12 and Hep3B cell lines, respectively. Mechanistically, we found that T. articulata methanolic extract induces cell death by activating apoptosis and autophagy pathways. First, T. articulata methanolic extract promoted autophagy, which was confirmed by acridine orange staining. The immunoblotting analysis further confirmed that the extract at higher doses consistently induced the conversion of LC3I to LC3II form with a gradual decrease in the expression of autophagy substrate protein p62. Second, T. articulata methanolic extract promoted reactive oxygen species production in hepatocellular carcinoma cells and activated reactive oxygen species-mediated apoptosis. Flow cytometry and immunoblotting analysis showed that the plant methanolic extract induced dose-dependent apoptosis and activated proapoptotic proteins caspase-3 and PARP1. Additionally, the extract triggered the arrest of the G0/G1 phase of the cell cycle and upregulated the protein expression of p27/Kip and p21/Cip, with a decrease in cyclin D1 expression in hepatocellular carcinoma cells.

NOVELTY AND SCIENTIFIC CONTRIBUTION

The current study demonstrates that T. articulata methanolic extract exhibits promising anticancer potential to kill tumour cells by programmed cell death type I and II mechanisms and could be explored for potential drug candidate molecules to curtail cancer in the future.

Comparative assessment of biological activities of different parts of halophytic plant Tamarix articulata (T. articulata) growing in Saudi Arabia

Owing to extremely high salinity and harsh environmental conditions, T. articulata is one of the most abundant wild plants growing in the deserts of Saudi Arabia. Such plants may contain novel compounds to display promising biological activities. Here, in this study, we evaluate the biological activities of methanolic extracts of fresh leaves, dry leaves, stem, and roots of T. articulata. The antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic and flavonoid content were determined using standard colorimetric methods. Whereas antimicrobial and ant-proliferative activities were determined by standard well-diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Our results demonstrate that all methanolic extracts of T. articulata showed antioxidant activity, however, the methanolic extract of dry leaves exhibits promising antioxidant effect with IC₅₀ value 49.08 ± 1.98, which was strongly supported by total phenolic (409.92 ± 6.03 mg GAE/g DW) and flavonoid (177.71 mg QE/g DW) content. Although, antimicrobial activity was also exhibited by all the methanolic extracts, however, methanolic extract of dry leaves exhibits promising antimicrobial activity in Gram-positive bacteria Staphylococcus epidemidis. Furthermore, MTT assay revealed that all methanolic extracts exhibit antiproliferative activity in MCF-7 (breast cancer) and RKO (colorectal cancer) cells with IC₅₀ values ranges from 219 ± 5.112 µg/ml to 253 ± 5.231 µg/ml and 220 ± 4.330 µg/ml to 325 ± 6.213 µg/ml, respectively. However, the most promising antiproliferative effect was displayed by methanolic extract of dry leaves with IC₅₀ values 219 ± 5.112 µg/ml and 220 ± 4.330 µg/ml, respectively. In summary, these findings provide evidence that T. articulata has promising biological activities and can be used for many pharmaceutical activities in the future.

Development of small molecule inhibitors targeting NLRP3 inflammasome pathway for inflammatory diseases

NLRP3 (Nod-like receptor protein 3) belongs to the NOD-like receptor family, which is activated by pathogen and damage-associated signals to form a multimeric protein complex, known as the NLRP3 inflammasome. NLRP3 inflammasome activation leads to release of proinflammatory cytokines IL-1β and IL-18, thus inducing pyroptosis, a programmed cell death mechanism. Dysregulation of the NLRP3 inflammasome pathway is closely related to the development of many human diseases, such as neuroinflammation, metabolic inflammation, and immune inflammation. Emerging studies have suggested NLRP3 inflammasome as a potential drug-target for inflammatory diseases. Several small molecules have recently been identified to target the NLRP3 inflammasome pathway directly or indirectly and alleviate related disease pathology. This review summarizes recent evolving landscape of small molecule inhibitor development targeting the NLRP3 inflammasome pathway.

In vitro and in silico insights into tyrosinase inhibitors with (E)-benzylidene-1-indanone derivatives

Tyrosinase is a key enzyme responsible for melanin biosynthesis and is effective in protecting skin damage caused by ultraviolet radiation. As part of ongoing efforts to discover potent tyrosinase inhibitors, we systematically designed and synthesized thirteen (E)-benzylidene-1-indanone derivatives (BID1–13) and determined their inhibitory activities against tyrosinase. Among the compounds evaluated, BID3 was the most potent inhibitor of mushroom tyrosinase (IC₅₀ = 0.034 µM, monophenolase activity; IC₅₀ = 1.39 µM, diphenolase activity). Kinetic studies revealed that BID3 demonstrated a mixed type of tyrosinase inhibition with K_i value of 2.4 µM using l-DOPA as a substrate. In silico molecular docking simulations demonstrated that BID3 can bind to the catalytic and allosteric sites of tyrosinase to inhibit enzyme activity which confirmed in vitro experimental studies between BID3 and tyrosinase. Furthermore, melanin contents decreased and cellular tyrosinase activity was inhibited after BID3 treatment. These observations revealed that BID3 is a potent tyrosinase inhibitor and potentially could be used as a whitening agent for the treatment of pigmentation-related disorders.

Antihypertensive activity of diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate: A continuation study in L-NAME treated wistar rats

In the present study, we report that neolignan1 (Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate) relaxes the superior mesenteric artery in a concentration dependent manner (pD2 value 5.392 ± 0.04; n = 8 for endothelium intact and 5.204 ± 0.03; n = 8 for endothelium denuded mesenteric rings, respectively). The relaxation response of neolignan1 was found to be endothelium independent and sensitive to 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-on (ODQ; 1 μM) and tetraethyl ammonium (TEA; 1 mM). In-silico studies showed good LibDock score (92.66) of neolignan1 with BK_Ca channel and are in well corroboration with ex-vivo study. Further, neolignan1 significantly decreased the systolic blood pressure, diastolic blood pressure and mean arterial pressure in the Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 50 mg/kg) treated Wistar rats at the dose of 30 and 100 mg/kg given once orally for 15 days. In addition, neolignan1 is well tolerated up to 100 mg/kg when given as a repeated dose, once orally for 28 days in Swiss albino mice. Neolignan1 was well absorbed from oral route, reached peak at 4 h and eliminated below detection level by 12 h after administration. Our present study concludes that neolignan1 produced relaxation in superior mesenteric artery by opening of BK_Ca channel and produced significant antihypertensive activity in L-NAME treated Wistar rats and was well tolerated by the experimental animal.

Antiproliferative Activity and Characterization of Metabolites of Aspergillus nidulans: An Endophytic Fungus from Nyctanthes arbor-tristis Linn. Against Three Human Cancer Cell Lines

BACKGROUND

Endophytic fungi are receiving attention as sources of structurally novel bioactive secondary metabolites towards drug discovery from natural products. This study reports the isolation and characterization of secondary metabolites from an endophytic fungus Aspergillus nidulans, associated with Nyctanthes arbor-tristis Linn., a plant which has a traditional use to cure many ailments including cancer.

OBJECTIVE

The objective of this study was to evaluate the antiproliferative activity of the metabolites of A. nidulans from N. arbor-tristis on three human cancer cell lines, lung (NCI-H460), breast (MCF-7) and uterine cervix (HeLa), and carry out their characterization.

METHODS

The extracts of the endophytic fungus cultured on potato dextrose agar were subjected to various chromatographic techniques. Structures of pure compounds were determined using spectroscopic techniques. The non-polar constituents were analyzed by GC-MS. Antiproliferative activity was determined by sulforhodamine B (SRB) assay.

RESULTS

The extracts and fractions showed moderate to good growth inhibition of the aforementioned human cancer cell lines. The broth extract was most potent (IC50 = 10 ± 3.1 μg/mL and LC50= 95 ± 3.9) against HeLa whereas petroleum ether insoluble fraction of mycelium was most active against NCI-H460 and MCF-7 (IC50 = 10 ± 2.1 µg/mL and 18 ± 3.1 µg/mL respectively). GC-MS led to identify 12 compounds in mycelium and 19 compounds in broth. Four pure compounds were isolated and characterized one compound 5, 10-dihydrophenazine-1-carboxylic acid (1) from broth and three 1-hydroxy-3-methylxanthone (2), ergosterol (3) and sterigmatocystin (4) from mycelium. 1 has not been reported earlier as a plant/fungal metabolite while 2-4 are new from this source. Sterigmatocystin exhibited growth inhibitory effect (IC50 = 50 ± 2.5 µM/mL) against only MCF-7 cell line whereas other compounds had IC50 > 100.

CONCLUSIONS

In this paper, the cytotoxicity of mycelium and broth constituents of endophytic fungus Aspergillus nidulans from Nyctanthes arbor-tristis is reported for the first time. The study shows that fungus Aspergillus nidulans from Nyctanthes arbor-tristis is capable of producing biologically active natural compounds and provides a scientific rationale for further chemical investigations of endophyte-producing natural products.

Antitumour, acute toxicity and molecular modeling studies of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one against Ehrlich ascites carcinoma and sarcoma-180

In an effort to discover an effective and selective antitumour agent, synthesis and anti-cancer potential of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one (SK-25), which has been reported earlier by us with significant cytotoxicity towards MiaPaCa-2 malignant cells, with an IC₅₀ value of 1.95 μM and was found to instigate apoptosis. In the present study, the antitumour efficacy of SK-25 was investigated on Ehrlich ascites tumour (EAT, solid), Sarcoma 180 (solid) tumour and Ehrlich ascites carcinoma. The compound was found to inhibit tumour development by 94.71% in Ehrlich ascites carcinoma (EAC), 59.06% in Ehrlich tumour (ET, solid) and 45.68% in Sarcoma-180 (solid) at 30 mg/kg dose. Additionally, SK-25 was established to be non-toxic at a maximum tolerated dose of 1000 mg/kg in acute oral toxicity in Swiss-albino mice. Computer-based predictions also show that the compounds could have an interesting DMPK profile since all 51 computed physicochemical parameters fall within the recommended range for 95% of known drugs. The current study provides insight for further investigation of the antitumour potential of the molecule.

Stereoselective synthesis of sulfonated 1-indenones via radical-triggered multi-component cyclization of β-alkynyl propenones

New radical-triggered multi-component cyclizations of β-alkynyl propenones have been developed, leading to 50 examples of sulfonated 1-indenones with generally good yields and high levels of stereoselectivity.

Structural studies of (E)-2-(benzylidene)-1-tetralone derivatives: crystal structures and Hirshfeld surface analysis

Crystal structures are reported from data collected at 100 K of (E)-2-(X-benzylidene)-1-tetralone (2: X=3-O2N; 3: X=4-O2N; 5: X=4-HO; 6: X=4-Me2N; 7: 4-NC), (E)-2-(X-benzylidene)-6-MeO-1-tetralone, 8, and (E)-2-(X-benzylidene)-5-MeO-1-tetralone 9. Also reported herein are the Hirshfeld surface calculations for these compounds as well as those of (E)-2-(X-benzylidene)-1-tetralone (1: X=H; 4: X=4-MeO), whose structures were previously reported. The molecules are not planar as shown by the dihedral angles of 45.66(5)–69.78(5)° between the phenyl groups and by the puckered cyclohexenyl rings. A common feature of the molecular conformations is the C–H···O1(carbonyl) intramolecular hydrogen bond. The carbonyl oxygen atom plays significant roles in the interactions in all compounds baring compound 8. However, there is no consistent set of intermolecular interaction in this group of compounds. Intermolecular interactions present in each compound are some of the O–H···O, C–H···A (A=O, N or π), A–O···π (A=C or N) and π···π interactions. The only compound exhibiting a classical O–H···O hydrogen bond is compound 5. C–H···π interactions are found in all compounds, and while π···π interactions are present in compounds 2, 3, 7 and 9, no consistent type of stacking arrangement is shown. The Hirshfeld surface calculations, while generally concurring with the intermolecular interactions indicated by PLATON analyses, also reveal short interactions, which fall below the PLATON cut-off parameters.

Aglycone solanidine and solasodine derivatives: A natural approach towards cancer

Over the past few years, it was suggested that a rational approach to treat cancer in clinical settings requires a multipronged approach that augments improvement in systemic efficiency along with modification in cellular phenotype leads to more efficient cell death response. Recently, the combinatory delivery of traditional chemotherapeutic drugs with natural compounds proved to be astonishing to deal with a variety of cancers, especially that are resistant to chemotherapeutic drugs. The natural compounds not only synergize the effects of chemotherapeutics but also minimize drug associated systemic toxicity. In this review, our primary focus was on antitumor effects of natural compounds. Previously, the drugs from natural sources are highly precise and safer than drugs of synthetic origins. Many natural compounds exhibit anti-cancer potentials by inducing apoptosis in different tumor models, in-vitro and in-vivo. Furthermore, natural compounds are also found equally useful in chemotherapeutic drug resistant tumors. Moreover, these Phyto-compounds also possess numerous other pharmacological properties such as antifungal, antimicrobial, antiprotozoal, and hepatoprotection. Aglycone solasodine and solanidine derivatives are the utmost important steroidal glycoalkaloids that are present in various Solanum species, are discussed here. These natural compounds are highly cytotoxic against different tumor cell lines. As the molecular weight is concerned; these are smaller molecular weight chemotherapeutic agents that induce cell death response by initiating apoptosis through both extrinsic and intrinsic pathways.

Structural studies of (E)-2-(benzylidene)- 2,3-dihydro-1H-inden-1-one derivatives: crystal structures and Hirshfeld surface analysis

Crystal structures are reported of (E)-2-(4-hydroxybenzylidene)-2,3-dihydro-1H-inden-1-one, 1, (E)-2-(4-dimethylaminobenzylidene)-2,3- dihydro-1H-inden-1-one, 2, (E)-2-(4-cyanobenzylidene)-2,3-dihydro-1H-inden-1-one, 3, and monoclinic-(E)- 2-(3-nitrobenzylidene)-2,3-dihydro-1H-inden-1-one, monoclinic-4, all from data collected at 100 K and (E)-2-(4-hydroxy-3,5-dimethylbenzylidene)-2,3-dihydro-1H-indan-1-one, 6, from data collected at 299 K. An earlier triclinic form of 4 has been reported. Also reported herein are the Hirshfeld suface calculations for these five compounds, as well as that of 2-(4-methoxybenzylidene)-2,3-dihydro-1H-inden-1-one, 5,whose crystal structure has been previously reported. The three rings in each of the compounds, 1–4 and 6, are essentially planar, including the five-membered ring containing a formally hydridized sp3 atom. The molecules exhibit slight deviations from overall planarity as shown by the dihedral angles, >8.15(6)° between the 2,3-dihydro-1H-inden-1-one fragments and the phenyl fragments. The main intermolecular interactions in compounds 1 and are classical O–H···O1(carbonyl) hydrogen bonds. The carbonyl oxygen atom in compounds 1–4 are involved in non-classical C–H···O intermolecular hydrogen bonds. Intermolecular C–H---π interactions are present in 2, 3 and 6, while π···π are present in 2–4 and 6. As noted in the structure determinations of these compounds, different π···π motifs are possible. The Hirshfeld surface calculations, while generally concurring with the intermolecular interactions indicated by PLATON analyses, also reveal significant interactions, which fall below the PLATON radar.

Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate exhibits antihypertensive activity in rats through increase in intracellular cGMP level and blockade of calcium channels

We report here the antihypertensive and vasorelaxant potential of some steroidal and non-steroidal compounds identified through a library of compounds. All the novel analogues showed vasorelaxant potential in isolated rat aorta. The most potent lead neolignan1 (Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate) produced concentration dependent relaxation with [pD₂ 5.16±0.05; n=16 and E_max 96.97%±1.12%; n=16]. The neolignan1 relaxation is independent of endothelium and is sensitive to ODQ (1H-[1, 2, 4] oxadiazolo [4, 3-a] quinoxalin-1-one; a blocker of soluble guanylyl cyclase (sGC) which synthesizes cGMP (cyclic guanosine monophosphate)). ELISA analysis of treated arterial tissues showed concentration-dependent increase in cGMP level in treated tissues compared to control (2.03 and 7.16 fold of control at 10 and 30µM of neolignan1, respectively) and a synergistic increase in cGMP level by 26.66 fold compared to control when used in combination with sildenafil (10µM; a known inducer of cGMP level by selectively blocking cGMP specific phosphodiesterase 5). Our present study reports for the first time that neolignans produce relaxation in isolated rat aorta through increase in intracellular cGMP level. The ODQ resistant relaxation of neolignan1 is mediated by blockade of voltage dependent L-type calcium channel (VDCC) as observed in the experiment with CaCl₂. Neolignan1 upon intravenous administration via tail vein in Spontaneously Hypertensive Rats (SHR) produced significant decrease in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP). The present study concludes that neolignan1 exhibited antihypertensive potential in rats through rise in intracellular cGMP and blockade of VDCC.

Arylidene indanone scaffold: medicinal chemistry and structure–activity relationship view

Arylidene indanone (AI) scaffolds are considered as the rigid cousins of chalcones, incorporating the α,β-unsaturated ketone system of chalcones forming a cyclic 5 membered ring.

Synthesis and bioactivity studies on new 4-(3-(4-Substitutedphenyl)-3a,4-dihydro-3H-indeno[1,2-c]pyrazol-2-yl) benzenesulfonamides

A series of new 4-(3-(4-substitutedphenyl)-3a,4-dihydro-3H-indeno[1,2-c]pyrazol-2-yl) benzenesulfonamides (7-12) was synthesized starting from 2-(4-substitutedbenzylidene)-2,3-dihydro-1H-inden-1-one (1-6) and 4-hydrazinobenzenesulfonamide. The substituted benzaldehydes from which the key intermediate was prepared by introducing 2- or 4-substituents such as fluorine, hydroxy, methoxy, or the 3,4,5-trimethoxy moieties. The compounds were tested for their cytotoxicity, tumor-specificity and potential as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The 3,4,5-trimethoxy and the 4-hydroxy derivatives showed interesting cytotoxic activities, which may be crucial for further anti-tumor activity studies, whereas some of these sulfonamides strongly inhibited both human (h) cytosolic isoforms hCA I and II.

Anticancer activity and toxicity profiles of 2-benzylidene indanone lead molecule

3-(3',4',5'-Trimethoxyphenyl)-4,5,6-trimethoxy,2-(3″,4″-methylenedioxybenzylidene)-indan-1-one (1) is an optimized anti-cancer lead molecule obtained on modification of gallic acid, a plant phenolic acid. It exhibited potent cytotoxicities (IC50=0.010-14.76μM) against various human carcinoma cells. In cell cycle analysis, benzylidene indanone 1 induced G2/M phase arrest in both MCF-7 and MDA-MB-231 cells. It also induced apoptosis in DU145 cells which was evident by cleavage of PARP. In Ehrlich ascites carcinoma, benzylidene indanone 1 showed 45.48% inhibition of tumour growth at 20mg/kg dose in Swiss albino mice. Further, in sub-acute toxicity experiment in Swiss-albino mice, it was found to be non-toxic up to 100mg/kg dose for 28days. The lead compound benzylidene indanone 1 can further be optimized for better anti-cancer activity.

Natural antitubulin agents: importance of 3,4,5-trimethoxyphenyl fragment

Microtubules are polar cytoskeletal filaments assembled from head-to-tail and comprised of lateral associations of α/β-tubulin heterodimers that play key role in various cellular processes. Because of their vital role in mitosis and various other cellular processes, microtubules have been attractive targets for several disease conditions and especially for cancer. Antitubulin is the most successful class of antimitotic agents in cancer chemotherapeutics. The target recognition of antimitotic agents as a ligand is not much explored so far. However, 3,4,5-trimethoxyphenyl fragment has been much highlighted and discussed in such type of interactions. In this review, some of the most important naturally occurring antimitotic agents and their interactions with microtubules are discussed with a special emphasis on the role of 3,4,5-trimethoxyphenyl unit. At last, some emerging naturally occurring antimitotic agents have also been tabulated.

Synthesis of 5-substituted-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one analogs and their biological evaluation as anticancer agents: mTOR inhibitors

A microwave assisted strategy for synthesis of series of 1H-pyrazolo[4,3-d]pyrimidin-7(6H)-ones has been developed and their biological evaluation as anticancer agents is described. The synthetic protocol involves simple procedure by oxidative coupling of 4-amino-1-methyl-3-propyl-1H-pyrazole-5-carboxamide with different aldehydes in presence of K2S2O8 offering 5-substituted-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one compounds in excellent yields. The in vitro anticancer activity screening against human cancer cell lines HeLa, CAKI-I, PC-3, MiaPaca-2, A549 gave good results. The in detailed mechanistic correlation studies of compound 3m revealed that the compound shows anticancer activity through apoptosis mechanism and also inhibits mTOR with nonomolar potency. The design was based on docking with mTOR protein. The concentration dependent cell cycle analysis, western blotting experiment and nuclear cell morphology studies have been described.

2-(Di-phenyl-methyl-idene)-2,3-di-hydro-1H-inden-1-one

In the title mol-ecule, C22H16O, the indanone ring system is approximately planar with a dihedral angle between the fused rings of 5.13 (14)°. Two benzene rings are linked together at one side of a double bond, sitting on either side of the indanone ring system and making dihedral angles of 70.30 (12) and 44.74 (13)° with it. In the crystal, hydrogen bonding is not present, but weak C-H⋯π or π-π inter-actions occur and mol-ecules form a sheet-like structure in the bc plane.