High-performance capillary electrophoretic method for the quantification of 5-methyl 2'-deoxycytidine in genomic DNA: application to plant,animal and human cancer tissues

A new approach to the evaluation of the relative degree of genomic DNA methylation through the quantification of 2'-deoxynucleosides is proposed. Detection and quantification of 5-methyl 2'-deoxycytidine in genomic DNA has been performed using micellar high-performance capillary electrophoresis (HPCE) with UV-Vis detection. This approach has been demonstrated to be more sensitive and specific than other HPCE methods for the quantification of DNA methylation degree and also to be faster than other HPLC-based methods. The detection and quantification of nucleosides through enzymatic hydrolyses notably increases the specificity of the technique and allows its exploitation in the analysis of poorly purified and/or concentrated DNA samples such as those obtained from meristematic plant regions and paraffin-embedded tissues.     

Urceolatin, a structurally unique bromophenol from Polysiphonia urceolata

6-Bromo-1-(3-bromo-4,5-dihydroxybenzyl)phenanthro[4,5-bcd]furan-2,3,5-triol (urceolatin, 1), a highly oxygenated bromophenol containing an unprecedented naturally occurring benzylphenanthro[4,5-bcd]furan unit, was isolated from the marine red alga Polysiphonia urceolata. Its structure was established on the basis of extensive spectroscopic analysis. Compound 1 displayed significant DPPH radical-scavenging activity with an IC50 value of 7.9 microM, which is 10-fold more potent than that of the positive control, butylated hydroxytoluene.     

Proteomics of human cancer tissues and cells

Proteomic analysis of cancer tissues and cells provides valuable information to identify promising targets for cancer diagnosis, prognosis and therapy. Novel strategies have emerged to optimize the workflow of tissue procurement, and tissue and cell selection, and to improve protocols for the extraction of protein from fresh, frozen and paraffin-embedded tissue. Moreover, in the context of advanced approaches to proteomics, mass spectrometry and array-based technologies strongly contribute to protein profiling of cancer tissues and cells.The focus of this review is the methods by which all the steps of a proteomic investigation on human-cancer tissue (from choice of the experimental model to validation of candidate biomarkers) should be performed, paying particular attention to recently developed strategies. The review also presents an overview of the most recent high-throughput proteomic studies in cancer research.     

Andrographolactone, a unique diterpene from Andrographis paniculata

Andrographolactone (1), possessing an unprecedented diterpene skeleton, was isolated from the EtOAc extract of the aerial parts of Andrographis paniculata. Its structure was established by NMR, IR, UV, and HRESIMS data and subsequently confirmed by X-ray diffraction analysis. A possible biogenetic pathway of 1 was also proposed. Bioassay showed that 1 exhibited cytotoxic activity.     

A simple biomimetic synthesis of dl-chamaejasmine, a unique 3,3'-biflavanone

[Reaction: see text] The first chemical synthesis of dl-chamaejasmine (1), a structurally unique 3,3'-biflavanone natural product, was achieved as shown above, by a two-step sequence starting from trimethyl ether derivatives of 3-iodonaringenin (cis + trans) involving (i) metallic lanthanum-mediated reductive dimerization in refluxing THF and (ii) global demethylation with BBr3 in CH2Cl2. This synthesis represents a generally applicable biomimetic (reductive) radical dimerization approach to the 3,3'-biflavonoids.     

Plocamenone,a unique halogenated monoterpene from the red alga,plocamium

The unique halogenated monoterpene, 7-bromo-2,6-dimethyl-4,4,8-trichloro-1,5(z)-octadiene-3-one, was isolated from the marine red alga $\text{Plocamium}$.     

Cyclopenicillone, a unique cyclopentenone from the cultures of Penicillium decumbens

Cyclopenicillone (1), possessing a unique 2,5-dimethylcyclopent-2-enone carbon skeleton, has been isolated from the cultures broth of the fungus Penicillium decumbens. The structure and absolute configuration of 1 were elucidated using a combination of NMR spectroscopy, CD data and computational approaches. Cyclopenicillone (1) demonstrated a dose-dependent (10-100 μM) inhibition against LPS-induced NO production in RAW264.7 macrophages.     

Trace element profiles in the hair of cancer patients

The trace element profiles of the scalp hair of cancer patients were measured and compared with those of healthy people. Significant differences were observed for several elements, especially for Au, I and Se.     

Production of 3', 4'-anhydrovinblastine: a unique chemical synthesis

Preliminary Investigations have led to the discovery that ferric ion can couple catharanthine and vindoline, in aqueous acidic media, to produce 3',4'-anhydrovinblastine as the major product. A conversion of 77% could be realized under optimized conditions.     

Caylobolide A, a unique 36-membered macrolactone from a Bahamian Lyngbya majuscula

[structure: see text]. A new 36-membered macrolactone, (25S,27S,29S,33S)-caylobolide A, was isolated from the Bahamian cyanobacterium Lyngbya majuscula. The structure of caylobolide contains an unprecedented repeated unit-a contiguous pentad of 1,5 diols-and a 1,3,5-triol. The relative steroechemistry of the 1,3,5-triol was determined using Kishi's Universal NMR database, and absolute stereochemistry at C25,27,29 and C33 were determined by Mosher's analysis. Caylobolide A exhibited in vitro cytotoxicity against human colon tumor cells (IC50 HCT 116, 9.9 microM).     

Maoecrystal Z, a cytotoxic diterpene from Isodon eriocalyx with a unique skeleton

[structure: see text] A novel diterpene with an unprecedented tetracyclic 6,7:8,15-di-seco-7,20-olide-6,8-cyclo-ent-kaurane skeleton, named maoecrystal Z (1), has been isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx (Labiatae). Its structure was determined by comprehensive NMR and MS spectroscopic analysis coupled with single-crystal X-ray crystallographic diffraction. Compound 1 exhibited comparable inhibitory effect against human K562 leukemia, MCF7 breast, and A2780 ovarian tumor cells with IC(50) = 2.90, 1.63, and 1.45 microg/mL and with camptothecin and paclitaxel as the positive controls.     

Electrophoretic identification of new genomic profiles with a modified selective amplification of microsatellite polymorphic loci technique based on AT/AAT polymorphic repeats

The present paper introduces improvements of the conventional selective amplification of microsatellite polymorphic loci (SAMPL) technique, that exploit AT-rich microsatellite primers. Generally, AT/AAT microsatellites are frequent components of eukaryotic genomes, but their ubiquity and polymorphic information content (PIC) could not be exploited yet, because standard SAMPL conditions did not allow amplifications. Here we report (i) on the design of new versatile AT-rich microsatellite primers, that are combined with (ii) a modified SAMPL adapter primer (called EcoRI-Short), and (iii) special polymerase chain reaction (PCR) amplification regimes. The novel SAMPL procedure expands the range of useful microsatellite primers to AT-rich sequences and produces a high number of bands and a clear banding pattern, and detects polymorphisms in otherwise nonpolymorphic genomes of plants (Dioscorea alata, D. rotundata) and a fungus (Mycosphaerella fijiensis).     

Mearsine,a unique isoquinuclidine alkaloid: x-ray crystal structure of mearsine picrate

X-ray crystallography shows that mearsine, a minor alkaloid of the north Queensland plant $\text{Peripentadenia mearsii}$, has the novel isoquinuclidine structure 1, which permits charge transfer to take place between carbonyl and an azomethine group.     

New marine diterpenoids,including a unique hydroperoxide,from a caribbean gorgonian coral of the genus pseudopterogorgia

Three new diterpenoids related to the aglycone components of the recently described pseudopterosins and seco-pseudopterosins have been isolated from an undescribed Pseudopterogorgia species from the Caribbean Sea. The new compounds, described on the basis of their NMR properties and chemical interconversions, appear to be related illustrating some interesting rearrangements of a tertiary hydroperoxide in this series.     

Epoxytwinol A, a novel unique angiogenesis inhibitor with C2 symmetry, produced by a fungus

We isolated a novel unique pentaketide dimer designated as epoxytwinol A from the fermentation broth of a fungus. The structure of epoxytwinol A was determined to have a new carbon skeleton with C(2) symmetry by elucidation of spectroscopic evidence. Epoxytwinol A inhibited endothelial cell migration stimulated by vascular endothelial growth factor (ED(100)= 2.6 microM).     

Synthesis, structure and unique reactivity of the ethylzinc derivative of a bicyclic guanidine

An equimolar reaction between ZnEt(2) and 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) results in the formation of EtZn(hpp) (1) which crystallizes as a trinuclear agglomerate with the guanidinate ligands spanning 4-coordinate Zn centers. Exposure of a pre-formed THF solution of 1 to undried air leads to a ZnO-incorporating derivative 1(4)·ZnO, while an analogous experiment with CH(2)Cl(2) as solvent leads to a novel tetranuclear mixed aggregate formulated as [EtOZn(hpp)](2)[ClZn(hpp)](2) (2). The composition of 2 indicates that its formation proceeds via a complex multi-step reaction route that involves not only the oxygenation of ZnEt moieties, but also the activation of CH(2)Cl(2), causing the transfer of a chloride anion to the Zn center. Compounds were characterized by (1)H NMR spectroscopy and single-crystal X-ray diffraction analysis.