Biodiversity and Bioactive Potential of Actinomycetes from Unexplored High Altitude Regions of Kargil, India.

The effectiveness of currently available antimicrobials and anticancer medications is steadily declining due to the emergence of drug resistance. Since actinobacteria are important producers of bioactive substances, we have isolated them from the soil samples of exotic North-Western Himalayan terrains. Out of 128 isolates, 39 strains were prioritized based on their bioactive potential. The diversity analysis revealed higher abundance distribution of actinomycetes in the soil of an open field (68.7%), followed by the mountainside (34.9%), from which most of the bioactive strains were obtained. The extract of the strain S26-11 was found to be highly active against Gram-positive Staphylococcus aureus and Bacillus subtilis with a MIC of 0.5 µg/mL and 1 µg/mL respectively. A cytotoxicity assay (sulforhodamine B) was performed on a series of cancer cell lines (PC-3, MCF-7, A-549, and HCT-116). The extract of the strain S26-11 showed cytotoxic activity against all cancer cell lines with an IC50 of 2 µg/mL against PC-3, 1.9 µg/mL against MCF-7, 0.52 µg/mL against A-549, and 0.83 µg/mL against HCT-116. Moreover, the antioxidant activity was assessed using a DPPH-based assay and the results revealed that the S17-8 isolate showed the highest antioxidant activity with IC50 of 114.136 µg/mL. The Response Surface Methodology (RSM) had helped to optimize the physical parameters for scaling up of the bioactive strain S26-11. The unexplored soil niches of Kargil (UT, Ladakh), India, is rich in actinomycetes which are having potential bioactivities, would be worth to explore for the discovery of bioactive compounds. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01133-1.

Divergent Signaling Pathways May Lead to Convergence in Cancer Therapy - A Review.

Cancer is a chaos of uncontrolled cell proliferation that has consistently invented new circuitry programs to operate inside the cell machinery. Globally, cancer statistics account for 65% of mortality worldwide, mainly due to the adoption of lifestyle behaviours. In 2020, FDA approved 40 new drugs, out of which 16 (40%) were approved as cancer drugs. Overall, the risk of dying from cancer decreased, but further reductions in cancer death rates can be accelerated by applying existing cancer control knowledge across all the population segments, emphasising those in the lowest socio-economic and other disadvantaged population. Various therapeutic regimes, including low-molecular-weight inhibitors, targeting oncogenic signaling pathways are under development. However, the pitfall of targeted therapies is the quick emergence of acquired drug resistance encumbered with toxic side effects. Several FDA acclaimed therapeutic legacies or biosimilars earmarked signaling pathways of rare diseases (cystic fibrosis, erythropoietic protoporphyria, neuromyelitis optica spectrum disorder, tenosynovial giant cell tumor, sickle cell disease, systemic sclerosis-associated interstitial lung disease, muscular dystrophy), neurological and psychiatric disorders, infectious diseases, heart, lung, circulatory, endocrine diseases, autoimmune conditions, cancers and blood disorders. When cancer progresses, these signals develop specific characteristics that can be targeted for anti-cancer therapy. The designer inhibitors have emerged as novel pharmaceutical interventions that aim to block the pathways in an effort to reverse the abnormal phenotype of the cancer cells. Numerous cell-signaling channels have evolved and invigorated to make off three-dimensional feedback networks. The magnitude of accessible information by pathways occupies curated information as a consortium. To fully appreciate the pivotal roles that signaling cascades play in tumor development, it is necessary to understand the involved signaling cascades in the interaction between cancer cells. The prime endeavour is to canonically curate all signaling pathways involving cell cycle, EGFR, MAPK, GPCR, PI3K/ AKT/mTOR, immune checkpoints, nuclear receptors, janus kinase, transcription activators etc., involving the manipulation of genetic and nuclear receptors. Here, we will summarize the vast amount of information describing the signals that mediate crosstalk between cancer cells and the targets related to this crosstalk.

Antimicrobial and Cytotoxic Potential of Helminthosporin from Rumex abyssiniscus Jacq. Discovered as a Novel Source of Syringic Acid and Bis(2-ethyloctyl) Phthalate.

Rumex abyssinicus Jacq. is a perennial medicinal herb widely used in traditional medicine to treat many diseases. Phytochemicals of the plant were isolated using column chromatography and thin layer chromatography techniques. Extract, fractions and pure compounds were screened for antimicrobial activity against sensitive and multi-drug resistant microbes and their cytotoxicity was performed on different cancer cell lines. The mechanism of action of purified helminthosporin as well as the potent fraction containing a mixture of two compounds was assessed. Fraction R7C3 was the most potent antibacterial with the lowest MIC value of 0.12 µg/mL. Helminthosporin was the most potent compound with the lowest MIC value of 1.95 µg/mL. The compound was more potent than the antibiotic chloramphenicol against multi-drug resistant (MDR) bacteria with MIC equal to 16 µg/mL. The fraction and helminthosporin were shown to destroy the cell wall of the yeast and bacteria, and DNA fragmentation effect on the genome of Candida albicans and Bacillus cereus. Helminthosporin was the most cytotoxic compound with IC50 ˂ 10 µM. Fraction R7C3 showed the most potent cytotoxic effects on all cancer cell lines, with IC50 ranging from ˂1 to 4.35 ng/mL. Our study is the first report on the mechanism of action of helminthosporin, a potent candidate in the development of new drugs against multi-resistant bacteria and cancer cells. In addition, this study uncovered Rumex abyssinicus as a new source of syringic acid and bis(2-ethyloctyl) phthalate.

Synthesis, Biological Activity and Molecular Docking Studies of Heterocyclic Chalcones.

Nineteen heterocyclic chalcones were synthesized from 4-acetyl-5-methylquinolylpyrazole and heteroaryl (imidazole, pyrazole, thiophene, indole and triazole) aldehydes and were screened in vitro using four tumor cell lines for their cytotoxic capability and for antimicrobial activity. The chalcone 5b exhibited the highest activity with IC50 values 2.14 µM against colon (HCT-116) and 5.0 µM, against prostate (PC-3) cancer cell lines and also displayed good activity against fungal strain (A. niger) with MIC value 9.1 µM. The chalcones 5q and 5p displayed good activity against bacterial strains (S. aureus) having MIC value 2.6 µM and fungal strain (C. albicans) having MIC value 5.4 µM, respectively. The molecular docking outcome revealed that the synthesized heterocyclic chalcones demonstrated hydrogen bond, hydrophobic and electrostatic interactions with their respective biochemical targets.

Anticancer Activity of Cordia dichotoma against a Panel of Human Cancer Cell Lines and Their Phytochemical Profiling via HPLC and GCMS.

The current study was conducted to examine the in vitro anticancer potential of Cordia dichotoma (bark, leaves, pulp and seed). The plant material was collected from UT of J&K and methodical bioassays were carried out on ten human cancer cell lines (Michigan Cancer Foundation-7 (MCF-7), M.D. Anderson-Metastatic Breast (MDA-MB-231), Neuroblastoma-2a (N2A), SH-SY5Y, U-251, HCT-116, SW-620, A-549, MIA PaCa-2, Panc-1) from five different origins (breast, CNS, colon, lung, pancreas) respectively. Methanolic extracts were produced and fractions were then obtained from the extracts and evaluated for cytotoxicity. Mechanistic assays, HPLC, and GCMS profiling were performed on the highest active fraction. The Sulforhodamine B (SRB) assay determined the in vitro cytotoxicity. The findings revealed that the bark portion had in vitro cytotoxicity against the A-549 human lung cancer cell line. To our knowledge, this is the first study to show that the plant's bark has anticancer properties and induced chromatin condensation, confirmed cell death via ROS generation, and significantly decreased colony formation in A-549 cell line from lung origin in a dose-dependent manner. Furthermore, HPLC and GCMS investigations indicated the presence of a number of bioactive molecules such as gallic acid (144,969.86) uV*sec, caffeic acid (104.26) uV*sec, ferulic acid (472.87) uV*sec, vanillic acid (13,775.39) uV*sec, palmitic acid (18.34%), cis vaccenic acid (28.81%), etc. and one of the compounds was reported for the first time from the bark. As a result of its promising efficacy, it may become an essential cancer chemopreventive or chemotherapeutic medication for patients with lung carcinoma.

Chitosan Engineered PAMAM Dendrimers as Nanoconstructs for the Enhanced Anti-Cancer Potential and Improved In vivo Brain Pharmacokinetics of Temozolomide.

PURPOSE: To establish a platform for the possibility of effective and safe delivery of Temozolomide (TMZ) to brain via surface engineered (polyamidoamine) PAMAM dendrimer for the treatment of glioblastoma. METHODS: The present study aims to investigate the efficacy of PAMAM-chitosan conjugate based TMZ nanoformulation (PCT) against gliomas in vitro as well as in vivo. The prepared nanoconjugated formulation was characterized by 1H NMR, FT-IR spectroscopy and for surface morphological parameters. The reported approach was also designed in such a way to ensure toxicity before in vivo delivery through conducting the hemolytic study. RESULT: Surface morphology was found as per nanoformulation via size, pdi and zeta potential measurement. PCT was more efficacious in terms of IC50 values compared to pure TMZ against U-251 and T-98G glioma cell lines. The in vivo pharmacokinetic parameters proved sustained release fashion such as half-life (t1/2) of 22.74 h (PCT) rather than15.35 h (TMZ) only. Higher concentration was found in heart than brain in bio-distribution studies. This study exhibits the potential applicability of dendrimer and CS in improving the anticancer activity and delivery of TMZ to brain. CONCLUSION: The attractive ex vivo cytotoxicity against two glioma cell lines; U-251 and T-98G and phase solubility studies of TMZ revealed remarkable results. In vivo studies of prepared nanoformulation were significant and promising that explored the double concentration of TMZ in brain due to surface functionality of dendrimer. The reported work is novel and non- obvious as none of such approaches using chitosan anchored dendrimer for TMZ delivery has been reported earlier.

Genotoxicity and immunotoxic effects of 1,2-dichloroethane in Wistar rats.

Dichloroethane is widely used as a solvent, degreasing agent and in a variety of commercial products, and is known for being a ubiquitous contaminant in the environment. Important sources principally include the emissions from industrial processes, improper consumption, storage, and disposal methods. In view of the fact that the mechanism of its genotoxicity has not been satisfactorily elucidated, the acute in vivo toxicological impact is assessed in Rattus norvegicus. A systematic investigation has been made involving the use of conventional methods along with molecular and flow cytometric approaches. The micronucleus and chromosomal aberration frequencies were significantly elevated in bone marrow cells exposed to three concentrations at multiple treatment durations indicating positive time- and dose-response relationships. The mitotic index significantly decreased in similar concentrations in contrast to normal control. Separate studies were performed on blood cells for comet assay. It revealed dichloroethane-induced DNA damage in all exposures readily explainable in a dose- and time-dependent manner. Recent molecular techniques were further employed using leukocytes for the cell apoptosis/cycle and mitochondrial membrane potential employing propidium iodide staining and rhodamine-123, respectively. The effect on mitochondrial membrane permeability, cell cycle phases, and the DNA damage was analyzed through flow cytometry. These indicators revealed dichloroethane treatment decreased the mitochondrial membrane potential, affected the cell cycle, and confirmed the DNA damage, leading to apoptosis of the cells of the immune system responsible for immunotoxic effects of dichloroethane on rat leukocytes.

An investigation of in vitro cytotoxicity and apoptotic potential of aromatic diselenides.

A target synthesis of a library of symmetric aromatic diselenides was attempted with the aim of generating anticancer lead compounds. Out of thirteen screened molecules (1-13) against a panel of human cancer cell lines, compound 8 exhibited highest cell growth inhibition in Human leukemia HL-60 cells with IC50 value of 8 µM. Compound 8 had a good pro-apoptotic potential as evidenced from several apoptotic protocols like DNA cell cycle analysis and monitoring of apoptotic bodies formation using phase contrast and nuclear microscopy with Hoechst 33,258. Also, 8 significantly inhibits S phase of the cell cycle and eventually trigger apoptosis in HL-60 cells through mitochondrial dependent pathway substantiated by the loss of mitochondrial potential. A theoretical investigation of DNA binding ability of 8 showed that it selectively bind to minor groove of DNA, where it is stabilized by hydrogen bonding and hydrophobic interactions.

Repurposing FDA approved drugs against Sterol C-24 methyltransferase of Leishmania donovani: A dual in silico and in vitro approach.

Leishmaniasis is a disease caused by the parasite Leishmania donovani affecting populations belonging to developing countries. The present study explores drug repurposing as an innovative strategy to identify new uses for approved clinical drugs, reducing the time and cost required for drug discovery. The three-dimensional structure of Leishmania donovani Sterol C-24 methyltransferase (LdSMT) was modeled and 1615 FDA-approved drugs from the ZINC database were computationally screened to identify the potent leads. Fulvestrant, docetaxel, indocyanine green, and iohexol were shortlisted as potential leads with the highest binding affinity and fitness scores for the concerned pathogenic receptor. Molecular dynamic simulation studies showed that the macromolecular complexes of indocyanine green and iohexol with LdSMT remained stable throughout the simulation and can be further evaluated experimentally for developing an effective drug. The proposed leads have further demonstrated promising safety profiles during cytotoxicity analysis on the J774.A1 macrophage cell line. Mechanistic analysis with these two drugs also revealed significant morphological alterations in the parasite, along with reduced intracellular parasitic load. Overall, this study demonstrates the potential of drug repurposing in identifying new treatments for leishmaniasis and other diseases affecting developing countries, highlighting the importance of considering approved clinical drugs for new applications.

A novel carissic acid from fruits of Carissa carandas induced apoptotic cell death in A-549 cells following the activation of caspases.

This study was designed to identify cytotoxic compounds from Carissa carandas extract. The cytotoxic activity of extract and fractions were assessed against eight cancer cell lines. The chloroform fraction obtained from methanolic extract exhibited significant activity against MCF-7, HT-29, A-549 with IC50 values of 3.98 µg/mL (MCF-7), 1.28µg/mL (HT-29) and 1.48 µg/mL (A-549) respectively. Further investigation led to the isolation of novel compound carissic acid (CA), which was confirmed by detailed spectroscopy studies. CA exhibited notable activity with IC50 values of 3.47 µM for A-549, 2.65 µM for HT-29 and 13.58 ± 0.59 µM for MCF-7 cells. CAcaused chromatin condensation with decrease of mitochondrial membrane potential and also confirmed cell death via Reactive Oxygen Species (ROS) generation and significantly decreased the colony formation in dose-dependent manner. The overall findings suggested that CA demonstrates cytotoxic effect by inhibiting cell proliferation and promoting apoptosis in lung (A-549) carcinoma cell line.

Raloxifene, a SERM targets PD-L1: an in-silico study.

OBJECTIVES: Immunotherapeutic interventions in cancer have been considerably successful and widely accepted for cancer treatment, but are costly and cannot be afforded by all patients. Because of the high cost, the pharmaceutical research groups across the world are sufficiently motivated to discover or design small molecule inhibitors to treat cancer through inhibition of the immune checkpoint proteins previously targeted with monoclonal antibodies. The presented study was designed with an aim to establish raloxifene, a selective estrogen receptor modulator (SERM) as a potential ligand of the immune checkpoint protein Programmed death ligand-1 (PD-L1). METHODS: In the presented study, the in-silico approach was used for identifying a lead molecule against PD-L1. The hits were screened using the similarity-search method, and drug-likeliness analysis, and the leads were identified through ligand-docking using Autodock. In-vitro cytotoxicity analysis was carried out using the standard sulphorhodamine B (SRB) assay and the wound healing analysis to show the inhibition of cellular migration was performed using the standard scratch assay. RESULTS: The in-silico study revealed that raloxifene showed a high drug likelihood and higher binding affinity with PD-L1 as compared to the positive control (BMS-1166; BMS is Bristol Myers Squibb). The binding of raloxifene was shown to occur in the same region as the FDA-approved monoclonal antibodies atezolizumab and durvalumab, indicating the potential of raloxifene for PD1/PD-L1 blockade. In the in-vitro studies, raloxifene showed a time-dependent reduction in IC50 values for the cell line HCT116 (colon cancer). The scratch assay also revealed that raloxifene significantly reduced the migratory potential of HCT-116 cells in-vitro. CONCLUSIONS: PD-L1 is a potential target of the SERM raloxifene in-silico. Overall, this study is one step further towards immune checkpoint blockade using small-molecule inhibitors.

Site-Selective Synthesis of C-17 Ester Derivatives of Natural Andrographolide for Evaluation as a Potential Anticancer Agent.

A library of 57 compounds of natural andrographolide was designed, synthesized, and screened for in vitro studies against four human cancer cell lines: A594, PC-3, MCF-7, and HCT-116. Most of the synthesized compounds displayed better cytotoxic profile against all tested cells compared to the parent andrographolide (1). The tested semisynthetic derivatives of andrographolide were found to be more sensitive toward lung carcinoma (A594) and prostate carcinoma (PC-3) cell lines. Among the synthesized compounds, the C-17 p-methoxy phenyl ester analog 8s inhibited cell proliferation effectively in A549 (IC50: 6.6 µM) and PC-3 (IC50: 5.9 µM) cell variants, and compound 9s exhibited the most potent activity against the A594 cell line, with an IC50 value of 3.5 µM. Further anticancer mechanistic investigation demonstrated that compound 9s displayed nuclear morphological changes and increased reactive oxygen species (ROS) with disturbed mitochondrial membrane potential (MMP) that can lead to apoptosis. To know the exact structure confirmation of intermediate compounds 4 and 5, single X-ray crystallography was performed, which supported the complete reaction design of this work.

Correction to "LC-PDA-MS/MS-Based Dereplication Guided Isolation of a New Optical Isomer of 19,20-Epoxycytochalasin-N and Its Cytotoxic Activity".

[This corrects the article DOI: 10.1021/acsomega.2c03037.].

Acyl derivatives of boswellic acids as inhibitors of NF-κB and STATs.

Boswellic acid acylates including their epimers were synthesized and screened against a panel of human cancer cell lines. They exhibited a range of cytotoxicity against various human cancer cell lines thereby leading to the development of a possible SAR. One of the identified lead compounds was found to be an inhibitor of the NF-κB and STAT proteins, warranting further investigations to be developed into a potential anticancer lead.

PARP cleavage and perturbance in mitochondrial membrane potential by 3-α-propionyloxy-ß-boswellic acid results in cancer cell death and tumor regression in murine models.

BACKGROUND: Apoptotic induction in cancer cells has become a major focus of anticancer therapeutics. In this regard, ß-boswellic acids, naturally occurring pentacyclic triterpenes, have demonstrated antiproliferative and cytotoxic effects against different types of cancers. Surprisingly, not much has been reported regarding the chemical modifications or preparation of structural analogs of the key constituents of ß-boswellic acid. AIM: The anticancer activity of 3-α-propionyloxy-ß-boswellic acid (POBA) was investigated and this article reports for the first time that the triterpenoid ring of the boswellic acid derivative POBA is targeting the PI3K pathway. MATERIALS & METHODS: Induction of apoptosis of the semi-synthetic derivative of ß-boswellic acid-POBA in vitro was analyzed using a battery of human cancer cell lines followed by cell cycle phase distribution, further validated by DNA fragmentation, and was found to cause mitochondrial membrane potential loss with ultrastructural changes, as observed by electron microscopy studies and expression study using PARP cleavage, as well as validated by in vivo anti-tumor activity. RESULTS: The cytotoxicity data revealed the sensitivity of various human cancer cell lines of varied tissue origin to ß-boswellic acid, which robustly induced cell cycle arrest, DNA fragmentation and loss of mitochondrial membrane potential. Morphological studies of the effects of POBA revealed loss of surface projections, chromatin condensation, apoptotic body formation and POBA-mediated PARP cleavage. For in vivo therapeutic experiments, murine tumor models were treated with POBA and the treatment resulted in a significantly higher level of growth inhibition and apoptosis was significantly induced. CONCLUSION: These findings demonstrate that acyl substituents/groups in the main skeleton of ß-boswellic acid have the potential to be potent chemotherapeutic agents.

LC-PDA-MS/MS-Based Dereplication Guided Isolation of a New Optical Isomer of 19,20-Epoxycytochalasin-N and Its Cytotoxic Activity.

The Rosellinia sanctae-cruciana extract was subjected to detailed liquid chromatography tandem mass spectrometry studies. A total of 38 peaks were annotated to m/z 508.26, m/z 510.28, m/z 524.26, m/z 526.28, m/z 540.26, m/z 542.27, and m/z 584.28 [M + H]+. The accurate mass, mutually supported UV/vis spectra, and database search identified these compounds as cytochalasins. Systematic dereplication helped identify a peak at m/z 540.26 [M + H]+ as the new compound. Further, the identified compound was purified by high-performance liquid chromatography and characterized by 2D NMR to be 19,20-epoxycytochalasin N1, a new optical isomer of 19,20-epoxycytochalasin-N. It exhibited substantial cytotoxicity with IC50 values ranging from 1.34 to 19.02 µM. This study shows a fast approach for dereplicating and identifying novel cytochalasin metabolites in crude extracts.

Transferrin-appended PEGylated nanoparticles for temozolomide delivery to brain: in vitro characterisation.

Polymer-based nanotechnologies are proposed to be an alternative for drug administration, delivery and targeting to those of conventional formulations. The blood brain barrier is frequently a rate-limiting factor in determining permeation of a drug into brain. In this study, the surface-engineered long-circulating PLGA nanoparticles (NPs) were assessed for brain-specific delivery. Long circulating NPs of PLGA- and PEG-synthesised copolymer were prepared by emulsification solvent evaporation method. Further, the surface of PEGylated NPs was modified by anchoring transferrin (Tf) ligand for receptor-mediated targeting to brain. NPs were characterised for shape and size, zeta potential, entrapment efficiency and in vitro drug release. In vitro cytotoxicity studies were performed on human cancer cell lines. Confocal Laser Scanning Microscopy studies show the enhanced uptake of Tf-appended PEGylated NPs and their localisation in the brain tissues. Hence, the specific role of Tf ligand on PEGylated NPs for brain delivery was confirmed.

BCG Vaccination Program Mitigates COVID19 Related Mortality: A Reality Check.

Since its origin in the Wuhan province of China in December 2019, Coronavirus Disease 19 (COVID-19) has spread to most parts of the world and has infected millions of people. However, the significant variability in the mortality rate across the world indicates some underlying factors, especially the immunity factors that may have a potential role in this variability. One such factor that is being discussed and tested is the Bacillus Calmette-Guerin (BCG) vaccine. The available evidence suggests that BCG vaccination provides broad protection against respiratory infections as well as other infections. Therefore, BCG may prove to be a barrier for COVID-19 infection and may offer a ray of hope. In this review, we contrasted BCG vaccination program with COVID-19 mortality and analyzed trained immunity and cross protection against unrelated pathogens due to BCG vaccination. On analyzing the available data, we observed that countries without universal BCG vaccination policy are severely affected, while countries having universal BCG policies are less affected. Based on these data, we propose that the SARS-CoV-2 related qualified immunity, cross protection against unrelated pathogens and COVID-19 impact variations could be partly explained by the different national policies regarding BCG childhood vaccination. The combination of reduced morbidity and mortality may make BCG vaccination a potential new tool in the fight against COVID-19.

Tandem MS-Based Metabolite Profiling of 19,20-Epoxycytochalasin C Reveals the Importance of a Hydroxy Group at the C7 Position for Biological Activity.

Seven cytochalasins, 19,20-epoxycytochalasin N, cytochalasin P1, deacetyl 19,20-epoxycytochalasin C, 19,20-epoxycytochalasin D, 19,20-epoxycytochalasin C, cytochalasin D, and cytochalasin C, were isolated from a fungal (Rosellinia sanctae-cruciana) crude extract. A cytotoxicity assay (sulforhodamine B) was performed on a series of cancer cell lines: HT-29, A-549, PC-3, HCT-116, SW-620, and MCF-7. Simultaneously, the liquid chromatography-mass spectrometry (LC-MS)/MS profile of 19,20-epoxycytochalasin C-treated cell lines revealed that 19,20-epoxycytochalasin C (m/z 524.25) oxidized to a metabolite of m/z 522.25 Da (-2 Da (-2H) from 19,20-epoxycytochalasin C). Further chemical oxidation of 19,20-epoxycytochalasin C using the Dess-Martin reagent produced an identical metabolite. It has been noticed that the parent molecule (19,20-epoxycytochalasin C) showed an IC50 of 650 nM (on HT-29), whereas for the oxidized metabolite (m/z 522.24) of 19,20-epoxycytochalasin C, the IC50 was >10 µM. It is clear that the parent molecule had 16 times higher cytotoxic potential as compared to the oxidized metabolite. The spectroscopic investigation indicated that the oxidation of the hydroxyl (-OH) group occurred at the C7 position in 19,20-epoxycyctochalsin C and led to the inactivation of 19,20-epoxycytochalasin C. Further, cell cycle analysis and histopathological evidence support the findings, and CDK2 could be a possible target of 19,20-epoxycyctochalasin C.

Synthesis of 4ß-N-polyaromatic substituted podophyllotoxins: DNA topoisomerase inhibition, anticancer and apoptosis-inducing activities.

A new class of 4ß-N-polyaromatic substituted podophyllotoxin congeners have been synthesized and evaluated for their DNA topoisomerase-II (topo-II) inhibition as well as anticancer potential in some human cancer cell lines. The ease of synthesis and interesting biological activities make the present series of polyaromatic-podophyllotoxin congeners as a promising new structure for the development of new anticancer agents based on podophyllotoxin scaffold.