Browse
Submit Data
Databases
API
Help

Dataset Information

11 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Antineoplastic agents. 595. Structural modifications of betulin and the X-ray crystal structure of an unusual betulin amine dimer.

ABSTRACT: The lupane-type triterpene betulin (1) has been subjected to a series of structural modifications for the purpose of evaluating resultant cancer cell growth inhibitory activity. The reaction sequence 7?11?12 was especially noteworthy in providing a betulin-derived amine dimer. Other unexpected synthetic results included the 11 and 13/14?17 conversions, which yielded an imidazo derivative. X-ray crystal structures of dimer 12 and intermediate 25 are reported. All of the betulin modifications were examined for anticancer activity against the P388 murine and human cell lines. Significant cancer cell growth inhibition was found for 4, 8, 9, 15/16, 19, 20, 24, and 26, which further defines the utility of the betulin scaffold.

SUBMITTER: Pettit GR

PROVIDER: S-EPMC4010298 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Antineoplastic agents. 595. Structural modifications of betulin and the X-ray crystal structure of an unusual betulin amine dimer.

Pettit George R GR Melody Noeleen N Hempenstall Frank F Chapuis Jean-Charles JC Groy Thomas L TL Williams Lee L

Journal of natural products 20140402 4

The lupane-type triterpene betulin (1) has been subjected to a series of structural modifications for the purpose of evaluating resultant cancer cell growth inhibitory activity. The reaction sequence 7→11→12 was especially noteworthy in providing a betulin-derived amine dimer. Other unexpected synthetic results included the 11 and 13/14→17 conversions, which yielded an imidazo derivative. X-ray crystal structures of dimer 12 and intermediate 25 are reported. All of the betulin modifications were ...[more]

PMID: 24694263

Similar Datasets

Antineoplastic agents. 590. X-ray crystal structure of dolastatin 16 and syntheses of the dolamethylleuine and dolaphenvaline units.

Project description:Three advances necessary to bring dolastatin 16 (1) into full-scale preclinical development as an anticancer drug have been accomplished. The X-ray crystal structure of dolastatin 16 has been solved, which allowed stereoselective syntheses of its two new amino acid units, dolamethylleuine (Dml) and dolaphenvaline (Dpv), to be completed. The X-ray crystal structures of synthetic Z-Dml and TFA-Dpv have also been completed.

| S-EPMC3111978 | biostudies-literature

Antineoplastic agents. 592. Highly effective cancer cell growth inhibitory structural modifications of dolastatin 10.

Project description:The dolastatin series of unique peptides, originally discovered as constituents of the sea hare Dolabella auricularia, is of increasing importance in providing biological leads, especially to new and useful anticancer drugs. Dolastatin 10 and three analogues, minor structural modifications designated auristatins, are currently in human cancer clinical trials. The present study was undertaken to explore delivery to the cancer sites by way of phosphate or quinoline modifications. The initial objectives, auristatin TP as sodium phosphate 3b (GI50 10(-2)-10(-4) ?g/mL), auristatin 2-AQ (4, GI50 10(-2)-10(-3) ?g/mL), and auristatin 6-AQ (5, GI50 10(-4) ?g/mL), exhibited superior cancer cell growth inhibitory properties.

| S-EPMC3116808 | biostudies-literature

Antineoplastic Agents Targeting Sphingolipid Pathways.

Project description:Emerging studies in the enigmatic area of bioactive lipids have made many exciting new discoveries in recent years. Once thought to play a strictly structural role in cellular function, it has since been determined that sphingolipids and their metabolites perform a vast variety of cellular functions beyond what was previously believed. Of utmost importance is their role in cellular signaling, for it is now well understood that select sphingolipids serve as bioactive molecules that play critical roles in both cancer cell death and survival, as well as other cellular responses such as chronic inflammation, protection from intestinal pathogens, and intrinsic protection from intestinal contents, each of which are associated with oncogenesis. Importantly, it has been demonstrated time and time again that many different tumors display dysregulation of sphingolipid metabolism, and the exact profile of said dysregulation has been proven to be useful in determining not only the presence of a tumor, but also the susceptibility to various chemotherapeutic drugs, as well as the metastasizing characteristics of the malignancies. Since these discoveries surfaced it has become apparent that the understanding of sphingolipid metabolism and profile will likely become of great importance in the clinic for both chemotherapy and diagnostics of cancer. The goal of this paper is to provide a comprehensive review of the current state of chemotherapeutic agents that target sphingolipid metabolism that are undergoing clinical trials. Additionally, we will formulate questions involving the use of sphingolipid metabolism as chemotherapeutic targets in need of further research.

| S-EPMC7256948 | biostudies-literature

Crystal structure of timothy grass allergen Phl p 12.0101 reveals an unusual profilin dimer.

Project description:Timothy grass pollen is a source of potent allergens. Among them, Phl p 1 and Phl p 5 are thought to be the most important, as a majority of timothy grass-allergic individuals have IgE antibodies directed against these two allergens. The profilin from timothy grass (Phl p 12) has been registered as a minor allergen, with up to 35% of individuals in populations of grass pollen allergic patients showing IgE binding to Phl p 12. Profilins are primarily minor allergens and are known for a high likelihood of co-sensitization as well as cross-reactivity situations caused by their sequence and structure similarity. The crystal structure of Phl p 12.0101 was determined and it revealed that this allergen may form an unusual dimer not previously observed among any profilins. For example, the Phl p 12 dimer has a completely different geometry and interface when compared with the latex profilin (Hev b 8) dimer that has its crystal structure determined. The structure of Phl p 12.0101 is described in the context of allergenic sensitization and allergy diagnostics. Moreover, the structure of the Phl p 12.0101 dimer is discussed, taking into account the production of recombinant allergens and their storage.

| S-EPMC8581678 | biostudies-literature

Antineoplastic agents. 571. Total synthesis of bacillistatin 2.

Project description:The first total synthesis of bacillistain 2 (2) has been achieved in 24 steps and 22.9% overall yield, providing a quite efficient route with maximal convergence. Notable features of this approach include two successful applications of the Mitsunobu reaction during respective assemblies of key intermediates 22 and 27, successful employment of 2-methyl-6-nitrobenzoic anhydride (MNBA) in the formation by lactonization of a macrocyclic (36-membered) ring, and very flexible access to structural modifications of the bacillistatin-type cyclodepsipeptides.

| S-EPMC2837129 | biostudies-literature

Antineoplastic agents. 553. The Texas grasshopper Brachystola magna.

Project description:Bioassay (P388 lymphocytic leukemia cell line and human cancer cell lines) guided separation of an extract prepared from the previously chemically uninvestigated Texas grasshopper Brachystola magna led to isolation of the cancer cell growth inhibitory pancratistatin (1), narciclasine (2), and ungeremine (3). Pancratistatin (1) was first isolated from the bulbs of Hymenocallis littoralis), and the original crystal structure was deduced by X-ray analysis of a monomethyl ether derivative. In the present study pancratistatin (1) was isolated from an extract of B. magna, which led to the X-ray crystal structure of this anticancer drug. Since isoquinoline derivatives 1-3 are previously known only as constituents of amaryllidaceous plants, some of the interesting implications of their rediscovery in the grasshopper B. magna that does not appear to utilize amaryllis family plants were discussed.

| S-EPMC3251507 | biostudies-literature

pH-responsive niosome-based nanocarriers of antineoplastic agents.

Project description:Differences in pH between the tumour interstitium and healthy tissues can be used to induce conformational changes in the nanocarrier structure, thereby triggering drug release at the desired site. In the present study, novel pH-responsive nanocarriers were developed by modifying conventional niosomes with hexadecyl-poly(acrylic acid)n copolymers (HD-PAAn). Niosomal vesicles were prepared by the thin film hydration method using Span 60, Span 60/Tween 60 and cholesterol as main constituents, and HD-PAA modifiers of different concentrations (0.5, 1, 2.5, 5 mol%). Next, two model substances, a water-soluble fluorescent dye (calcein) and a hydrophobic agent with pronounced antineoplastic activity (curcumin), were loaded in the aqueous core and hydrophobic membrane of the elaborated niosomes, respectively. Physicochemical properties of blank and loaded nanocarriers such as hydrodynamic diameter (Dh), size distribution, zeta potential, morphology and pH-responsiveness were investigated in detail. The cytotoxicity of niosomal curcumin was evaluated against human malignant cell lines of different origins (MJ, T-24, HUT-78), and the mechanistic aspects of proapoptotic effects were elucidated. The formulation composed of Span 60/Tween 60/cholesterol/2.5% HD-PAA17 exhibited optimal physicochemical characteristics (Dh 302 nm; ζ potential -22.1 mV; high curcumin entrapment 83%), pH-dependent drug release and improved cytotoxic and apoptogenic activity compared to free curcumin.

| S-EPMC11008427 | biostudies-literature

Conjugates of betulin derivatives with AZT as potent anti-HIV agents.

Project description:Fourteen novel conjugates of 3,28-di-O-acylbetulins with AZT were prepared as anti-HIV agents, based on our previously reported potent anti-HIV triterpene leads, including 3-O-acyl and 3,28-di-O-acylbetulins. Nine of the conjugates (49-53, 55, 56, 59, and 60) exhibited potent anti-HIV activity at the submicromolar level, with EC(50) values ranging from 0.040 to 0.098muM in HIV-1(NL4-3) infected MT-4 cells. These compounds were equipotent or more potent than 3-O-(3',3'-dimethylsuccinyl)betulinic acid (2), which is currently in Phase IIb anti-AIDS clinical trial.

| S-EPMC3016297 | biostudies-literature

Crystal structure and characterization of a new copper(II) chloride dimer with meth-yl(pyridin-2-yl-methyl-idene)amine.

Project description:The new copper(II) complex, namely, di-?-chlorido-bis-{chlorido-[meth-yl(pyri-din-2-yl-methyl-idene)amine-?2 N,N']copper(II)}, [Cu2Cl4(C7H8N2)2], (I), with the ligand 2-pyridyl-methyl-N-methyl-imine (L, a product of Schiff base condensation between methyl-amine and 2-pyridine-carbaldehyde) is built of discrete centrosymmetric dimers. The coordination about the CuII ion can be described as distorted square pyramidal. The base of the pyramid consists of two nitro-gen atoms from the bidentate chelate L [Cu-N = 2.0241?(9), 2.0374?(8)?Å] and two chlorine atoms [Cu-Cl = 2.2500?(3), 2.2835?(3)?Å]. The apical position is occupied by another Cl atom with the apical bond being significantly elongated at 2.6112?(3)?Å. The trans angles of the base are 155.16?(3) and 173.79?(2)°. The Cu?Cu separation in the dimer is 3.4346?(3)?Å. In the crystal structure, the loosely packed dimers are arranged in stacks propagating along the a axis. The X-band polycrystalline 77?K EPR spectrum of (I) demonstrates a typical axial pattern characteristic of mononuclear CuII complexes. Compound (I) is redox active and shows a cyclic voltammetric response with E 1/2 = -0.037?V versus silver-silver chloride electrode (SSCE) assignable to the reduction peak of CuII/CuI in methanol as solvent.

| S-EPMC7274002 | biostudies-literature

Unusual Fluorescence Behavior of Pyrene-Amine Containing Dendrimers.

Project description:A new class of pyrene-based dendrimers, characterized by the presence of a 1,4,7,10-Tetraazacyclododecane (cyclen) unit as the core, was studied by SSF (steady-state fluorescence) and SPC (single-photon counting fluorescence). The photophysical behavior of these dendrimers was studied in THF, DMF and DMSO solution. The typical signals for pyrene-labeled molecules were recorded in each solvent, showing the representative fluorescence spectra: the corresponding emissions of monomer and excimer of the pyrene chromophore are observed. Unexpectedly, the typical quenching of tertiary amine on the pyrene emission was not observed in these dendrimers. Quenching studies were performed by adding up to 3 equivalents of trifluoroacetic acid (TFA). To our knowledge, this is the first report of pyrene's unquenching behavior by a tertiary amine.

| S-EPMC6891302 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data