Synthesis of oxadiazole–morpholine derivatives and manifestation of the repressed CD31 Microvessel Density (MVD) as tumoral angiogenic parameters in Dalton’s Lymphoma

Venkatesh, Nagaraj Parisara, B. T. Prabhakar, Pramod.S.N.. Characterization of antioxidant, anti-cancer, and immunomodulatory functions of partially purified garlic (Allium sativum L.) lectin

Introduction and Aim: The metabolic and oxidative stress induces highly reactive free radicals that are known to harm normal physiology and play a role in the development of cancer. Elevated levels of these free radicals contribute to excessive neovascularization leading to angiogenesis mediated cancer progression. Targeting these free radicals through dietary source is important strategy in regulation of cancer. Allium sativum L. (AsL) garlic has important multi pharmacological properties. On the other hand, dietary lectins are proven to be the best anti-cancer molecules. The study presents investigation that focus to assess the antioxidant, immunomodulatory and anticancer activities of partially purified garlic lectin (PPAsL).  Materials and Methods: Fresh garlic bulbs were processed and evaluated for lectin induced HA activity. Further the garlic lectins (AsL) were partially purified by ammonium sulphate precipitation and dialysis and analyzed through SDS-PAGE. Further lectins were characterized by producing Anti-AsL polyclonal antibodies and purification by affinity chromatography. Pharmacological evaluations of the lectins were assessed through antioxidant, anti-proliferative and antiangiogenic mediated anti-cancer activity. Results: Lectin positive activity was confirmed by HA activity and partial purification lectin identified ?12kDa protein having Glc/Man glycan specificity. The polyclonal antibodies raised against PPAsL, confirmed that it has potent immunogen. Pharmacological evaluation confirmed that PPAsL has potent antioxidant, antiangiogenic and antiproliferative effect both in-vitro and in-vivo.  Conclusion: PPAsL is potent antioxidant, anti-proliferative and anti-cancer molecule. The dietary recommendation of the garlic lectin is an important therapeutic strategy against the cancer.

Synthesis, Characterization, Hirshfeld Surface Analysis, Crystal Structure and Molecular Modeling Studies of 1-(4-(Methoxy(phenyl)methyl)-2-methylphenoxy)butan-2-one Derivative as a Novel α-Glucosidase Inhibitor

The crystal compound was synthesized and characterized using conventional analytical techniques. The compound C19H21O3 crystallizes in a monoclinic crystal system with the space group P21/c. The crystal structure is stabilized by C-H…O interactions. The structure is further reinforced by π-π interactions. During in vitro inhibition of α-glucosidase, the crystal compound exhibited a significant inhibition of the enzyme (IC50: 10.30 ± 0.25 µg/mL) in comparison with the control, acarbose (IC50: 12.00 ± 0.10 µg/mL). Molecular docking studies were carried out for the crystal compound with the α-glucosidase protein model, which demonstrated that the crystal molecule has a good binding affinity (−10.8 kcal/mol) compared with that of acarbose (−8.2 kcal/mol). The molecular dynamics simulations and binding free energy calculations depicted the stability of the crystal molecule throughout the simulation period (100 ns). Further, a Hirshfeld analysis was carried out in order to understand the packing pattern and intermolecular interactions. The energy difference between the frontier molecular orbitals (FMO) was 4.95 eV.

Synthesis and In Vitro Activity of Novel Melphalan Analogs in Hematological Malignancy Cells

Despite the continuous developments in pharmacology and the high therapeutic effect of new treatment options for patients with hematological malignancies, these diseases remain a major health issue. Our study aimed to synthesize, analyze in silico, and determine the biological properties of new melphalan derivatives. We obtained three methyl esters of melphalan having in their structures amidine moieties substituted with thiomorpholine (EM-T-MEL), indoline (EM-I-MEL), or 4-(4-morpholinyl) piperidine (EM-MORPIP-MEL). These have not yet been described in the literature. The in vitro anticancer properties of the analogs were determined against THP1, HL60, and RPMI8226 cells. Melphalan derivatives were evaluated for cytotoxicity (resazurin viability assay), genotoxicity (alkaline comet assay), and their ability to induce apoptosis (Hoechst33342/propidium iodide double staining method; phosphatidylserine translocation; and caspase 3/7, 8, and 9 activity measurements). Changes in mitochondrial membrane potential were examined using the specific fluorescence probe JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazol carbocyanine). The EM-T-MEL derivative had the highest biological activity, showing higher cytotoxic and genotoxic properties than the parent drug. Moreover, it showed a high ability to induce apoptosis in the tested cancer cells. This compound also had a beneficial effect in peripheral blood mononuclear cells (PBMC). In conclusion, we verified and confirmed the hypothesis that chemical modifications of the melphalan structure improved its anticancer properties. The conducted study allowed the selection of the compound with the highest biological activity and provided a basis for chemical structure-biological activity analyses.

Design, synthesis and molecular docking of benzophenone conjugated with oxadiazole sulphur bridge pyrazole pharmacophores as anti inflammatory and analgesic agents

The prostaglandins (PG) a group of physiologically active lipid compounds having diverse hormone like effects are important mediators of the body's response to pain and inflammation, and are formed from essential fatty acids found in cell membranes. This reaction is catalyzed by cyclooxygenase, a membrane associated enzyme occurring in two isoforms, COX-1 and COX-2. Nonsteroidal anti-inflammatory drugs (NSAIDs) act by inhibiting the activity of COX. In view of this, a series of novel benzophenones conjugated with oxadiazole sulphur bridge pyrazole moiety 8a-l were designed, synthesized, characterized and subsequently evaluated for anti-inflammatory and analgesic property. The investigation of novel analogues 8a-l for potential anti-inflammatory activity showed high levels of COX-1 and COX-2 inhibitory activity. Among the series, compound 8i with electron withdrawing fluoro group at the para position of the benzoyl ring of benzophenone was characterized by highest IC₅₀ values for both COX-1 and COX-2 inhibition, which is comparable to the standard drug. Further, molecular docking studies have been performed for the potent compound.

Monosubstituted hydrazone β-cyclodextrin derivatives for pH-sensitive complex formation with aromatic drugs

A new and convenient synthetic pathway was developed to produce monosubstituted cyclodextrins with high yields. Each of the β-cyclodextrin derivatives described in this work has an aromatic substituent connected with cyclodextrin core by a pH-sensitive hydrazone linker and a carbon chain. Carbon chains differ in lengths having one or three carbon atoms. The correlation between water solubility and linker length was determined using UV–Vis spectroscopy, while the dependence of hydrazone bond hydrolysis on the electrolyte pH was confirmed by cyclic voltammetry. The pH-dependent complex-formation ability between the hydrazone derivative of cyclodextrin and anthracycline drug was examined by square wave voltammetry. The significantly big solubility and the appropriate pH, at which the hydrolysis of the hydrazone bond occurs, make the newly synthesized derivatives attractive for pharmaceutical and medical applications.

Enhanced antitumor effect on intrapulmonary tumors of docetaxel lung-targeted liposomes in a rabbit model of VX2 orthotopic lung cancer

Allergic reactions and severe systemic toxicity are two major challenges for the clinical application of docetaxel (DTX) for treatment of non-small-cell lung cancer (NSCLC). We developed a novel lung-targeted DTX-loaded liposome (DTX-LP), an efficient drug delivery system, with a patented DBaumNC technology to overcome these deficiencies. In the present study, we describe the targeting activity, tumor inhibition rate (TIR), survival, pathology, tumor apoptosis and metabolism of DTX after intravenous injection of DTX-LP compared to the DTX injection (DTX-IN) formulation based on the VX2 orthotopic lung cancer rabbit model. Biodistribution studies revealed the highest accumulation in lung and tumor within 12 h after the injection of DTX-LP. The increased TIR indicates that the growth of tumor was slowed. Pathology tests demonstrated that DTX-LP can reduce metastasis and toxicity to non-targeted organs, leading to greatly extended survival time and improved survival of tumor-bearing rabbits. Flow cytometry and immunohistochemistry confirmed that DTX-LP is highly efficacious in tumor tissue, leading to a significant increase of tumor apoptosis and decrease of proliferation and angiogenesis. The results from this study demonstrate the increased intrapulmonary tumor targeting activity, enhanced antitumor effect and reduced toxicity of DTX-LP compared to DTX-IN and highlight its clinical prospects for NSCLC therapy.

Immunomodulatory glc/man-directed Dolichos lablab lectin (DLL) evokes anti-tumour response in vivo by counteracting angiogenic gene expressions

Neovascularization and jeopardized immunity has been critically emphasized for the establishment of malignant progression. Lectins are the diverse class of carbohydrate interacting proteins, having great potential as immunopotentiating and anti-cancer agents. The present investigation sought to demonstrate the anti-proliferative activity of Dolichos lablab lectin (DLL) encompassing immunomodulatory attributes. DLL specific to glucose and mannose carbohydrate moieties has been purified to homogeneity from the common dietary legume D. lablab. Results elucidated that DLL agglutinated blood cells non-specifically and displayed striking mitogenicity to human and murine lymphocytes in vitro with interleukin (IL)-2 production. The DLL-conditioned medium exerted cytotoxicity towards malignant cells and neoangiogenesis in vitro. Similarly, in-vivo anti-tumour investigation of DLL elucidated the regressed proliferation of ascitic and solid tumour cells, which was paralleled with blockade of tumour neovasculature. DLL-treated mice showed an up-regulated immunoregulatory cytokine IL-2 in contrast to severely declined levels in control mice. Mechanistic validation revealed that DLL has abrogated the microvessel formation by weakening the proangiogenic signals, specifically nuclear factor kappa B (NF-κB), hypoxia inducible factor 1α (HIF-1 α), matrix metalloproteinase (MMP)-2 and 9 and vascular endothelial growth factor (VEGF) in malignant cells leading to tumour regression. In summary, it is evident that the dietary lectin DLL potentially dampens the malignant establishment by mitigating neoangiogenesis and immune shutdown. For the first time, to our knowledge, this study illustrates the critical role of DLL as an immunostimulatory and anti-angiogenic molecule in cancer therapeutics.

Synthesis of novel morpholine conjugated benzophenone analogues and evaluation of antagonistic role against neoplastic development

A series of novel 4-benzyl-morpholine-2-carboxylic acid N'-[2-(4-benzoyl-phenoxy)-acetyl]-hydrazide derivatives 8a-j has been synthesized from (4-hydroxy-aryl)-aryl methanones through a multi-step reaction sequence and then evaluated for anti-proliferative activity in vitro against various types of neoplastic cells of mouse and human such as DLA, EAC, MCF-7 and A549 cells. From the cytotoxic studies and structural activity relationship of compounds 8a-j, it is clear that methyl group on the B ring of benzophenone is essential for antiproliferative activity and bromo at ortho position (compound 8b) and methyl at para position (compound 8f) on A ring of benzophenone are significant for extensive anti-mitogenic activity. Investigation on clonogenesis and Fluorescence-activated cell sorting suggests that compounds 8b and 8f have the potency to exhibit the prolonged activity with cell cycle arrest on G2/M phase against cancer progression. Further, the compounds 8b and 8f inhibit murine ascites lymphoma through caspase activated DNase mediated apoptosis.

A tumoural angiogenic gateway blocker, Benzophenone-1B represses the HIF-1α nuclear translocation and its target gene activation against neoplastic progression

Hypoxia is an important module in all solid tumours to promote angiogenesis, invasion and metastasis. Stabilization and subsequent nuclear localization of HIF-1α subunits result in the activation of tumour promoting target genes such as VEGF, MMPs, Flt-1, Ang-1 etc. which plays a pivotal role in adaptation of tumour cells to hypoxia. Increased HIF-α and its nuclear translocation have been correlated with pronounced angiogenesis, aggressive tumour growth and poor patient prognosis leading to current interest in HIF-1α as an anticancer drug target. Benzophenone-1B ([4-(1H-benzimidazol-2-ylmethoxy)-3,5-dimethylphenyl]-(4-methoxyphenyl) methanone, or BP-1B) is a new antineoplastic agent with potential angiopreventive effects. Current investigation reports the cellular biochemical modulation underlying BP-1B cytotoxic/antiangiogenic effects. Experimental evidences postulate that BP-1B exhibits the tumour specific cytotoxic actions against various cancer types with prolonged action. Moreover BP-1B efficiently counteracts endothelial cell capillary formation in in-vitro, in-vivo non-tumour and tumour angiogenic systems. Molecular signaling studies reveal that BP-1B arrests nuclear translocation of HIF-1α devoid of p42/44 pathway under CoCl₂ induced hypoxic conditions in various cancer cells thereby leading to abrogated HIF-1α dependent activation of VEGF-A, Flt-1, MMP-2, MMP -9 and Ang-1 angiogenic factors resulting in retarded cell migration and invasions. The in-vitro results were reproducible in the reliable in-vivo solid tumour model. Taken together, we conclude that BP-1B impairs angiogenesis by blocking nuclear localization of HIF-1α which can be translated into a potent HIF-1α inhibitor.

BP-1T, an antiangiogenic benzophenone-thiazole pharmacophore, counteracts HIF-1 signalling through p53/MDM2-mediated HIF-1α proteasomal degradation

Hypoxia is a feature of all solid tumours, contributing to tumour progression. Activation of HIF-1α plays a critical role in promoting tumour angiogenesis and metastasis. Since its expression is positively correlated with poor prognosis for cancer patients, HIF-1α is one of the most convincing anticancer targets. BP-1T is a novel antiproliferative agent with promising antiangiogenic effects. In the present study, the molecular mechanism underlying cytotoxic/antiangiogenic effects of BP-1T on tumour/non-tumour angiogenesis was evaluated. Evidences show that BP-1T exhibits potent cytotoxicity with prolonged activity and effectively regressed neovessel formation both in reliable non-tumour and tumour angiogenic models. The expression of CoCl₂-induced HIF-1α was inhibited by BP-1T in various p53 (WT)-expressing cancer cells, including A549, MCF-7 and DLA, but not in mutant p53-expressing SCC-9 cells. Mechanistically, BP-1T mediates the HIF-1α proteasomal degradation by activating p53/MDM2 pathway and thereby downregulated HIF-1α-dependent angiogenic genes such as VEGF-A, Flt-1, MMP-2 and MMP-9 under hypoxic condition of in vitro and in vivo solid tumour, eventually leading to abolition of migration and invasion. Based on these observations, we conclude that BP-1T acts on HIF-1α degradation through p53/MDM2 proteasome pathway.

Relationship between microvessel density and cancer stem cells in tumor angiogenesis: a meta-analysis

Aim: Several studies have shown that cancer stem cells (CSCs) promote tumor angiogenesis and are involved in tumor growth. A meta-analysis was conducted to evaluate the association between cancer stem cell markers expression and microvessel density (MVD). Methods: Relevant literature was identified from diverse databases. The Stata 12.0 and Review Manager 5.3 software were used to performed meta-analysis. Results: Sixteen studies investigating the correlation between CSCs and tumor angiogenesis were included in a total of 1409 cases. The result showed that positive CSC markers expression were associated with increased MVD count in human tumors and CSC-transplanted mouse tumor models (p < 0.0001). Conclusion: CSCs may be associated with angiogenesis during the growth and development of tumors.

Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb Under Syngas Conditions

A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives.

Ethyl 2-(4-chloro-3-methylphenoxy)acetate

In the title compound, C11H13ClO3, the pendant ethyl chain has an extended conformation and lies in the plane of the substituted benzene ring; the r.m.s. deviation of the 15 non-H atoms comprising the molecule is 0.002 Å. The crystal structure features inversion-related dimers linked by pairs of benzene–carbonyl C—H...O hydrogen bonds, generatingR22(16) loops.

Synthesis and an angiolytic role of novel piperazine-benzothiazole analogues on neovascularization, a chief tumoral parameter in neoplastic development

A novel series of benzoic acid N'-[2-(4-benzothiazol-2-yl-piperazin-1-yl)-acetyl]-hydrazides 6a-j were synthesized and characterized by IR, (1)H, (13)C NMR, elemental and mass spectral analyses. The in-vitro cytotoxicity and cell viability assay of the synthesized compounds 6a-j were evaluated against Dalton's lymphoma ascites (DLA) cells. Our results showed that compound 6c with a bromo group on phenyl ring has showed promising antiproliferative efficacy. Further investigation of compound 6c on in-vivo treatment model depicts the increased tumor suppression through inhibition of angiogenesis.