Cleavage mechanism and anti-tumor activity of 3,6-epidioxy-1,10-bisaboladiene isolated from edible wild plants

A bisabolane sesquiterpene endoperoxide compound, 3,6-epidioxy-1,10-bisaboladiene (EDBD), was isolated from edible wild plants grown in the northern area of Japan, Cacalia delphiniifolia and Cacalia hastata, using a mutant yeast (cdc2-1 rad9Δ). It showed cytotoxicity at IC(50) = 3.4 μM and induced apoptosis against the human promyelocytic leukemia cell line HL60 through a new stable rearrangement product (1) when in the presence of FeSO(4). This conversion mechanism is different from another sesquiterpene endoperoxide lactone compound, dihydroartemisinin (DHA), which is an anti-malarial drug. The cytotoxicity of EDBD decreased in the presence of the ferrous ion chelating drug deferoxamine mesylate (DFOM), and this suggested that the structural change of the drug caused by Fe(2+) may be responsible for its biological activities. EDBD induced apoptosis via phosphorylation of p38 mitogen-activated protein kinase (MAPK) in HL60 cells, and was detected by Western blot. EDBD resulted in an immediate increase in DCF fluorescence intensity in HL60 cells using DCFH-DA (2',7'-dichlorofluorescin diacetate) assay. The in vitro reaction of EDBD with FeSO(4) also increased DCF fluorescence intensity in a dose dependent manner. These results showed that the biological activity of EDBD involves an unstable carbon-centered radical intermediate. Furthermore, there was no similarity between the JFCR39 fingerprints of EDBD and DHA (correlation coefficient on COMPARE Analysis γ = 0.158). EDBD showed anti-tumor effects against a xenograft of Lox-IMVI cells in vivo.     

Synthesis of phenserine analogues and evaluation of their cholinesterase inhibitory activities

Phenserine is a potentially attractive drug for Alzheimer's disease. In order to further expand SAR study for inhibitions of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), the methyl group at the 3a-position of phenserine was replaced with an alkyl or alkenyl group, and its phenylcarbamoyl moiety was substituted at the o- or p-position. The synthetic methodology for these phenserine analogues includes the efficient cascade reactions for introduction of the 3a-substituent and assembly of the quaternary carbon center followed by reductive cyclization to the key pyrroloindoline structure. The bulkiness of the substituent at 3a-position of phenserine derivatives tends to reduce the inhibitory effect on AChE activity in the following order: methyl>ethyl>vinyl>propyl≈allyl>reverse-prenyl groups. Among the series synthesized, the 3a-ethyl derivative demonstrated the highest AChE selectivity. In construct, the 3a-reverse-prenyl derivative indicated modest BuChE selectivity.     

Facile synthesis and evaluation of C-functionalized benzyl-1-oxa-4,7,10-triazacyclododecane-N,N',N″-triacetic acid as chelating agent for ¹¹¹In-labeled polypeptides

A 12-membered polyazamacrocycle, 1-oxa-4,7,10-triazacyclododecane-N,N′,N″-triacetic acid (ODTA), has been reported to provide an indium chelate of net neutral charge with thermodynamic stability higher than 1,4,7,10-tetraazacyclododecane-N,N′,N″,N?-tetraacetic acid (DOTA). However, neither synthetic procedure for a C-functionalized ODTA (C-ODTA) nor its chelating ability with a trace amount of radioactive indium-111 (¹¹¹In) has been elucidated. We herein present a facile synthetic procedure for C-ODTA, and estimated its ability as a chelating agent for radiolabeling peptides and proteins with ¹¹¹In. The synthetic procedure involves the synthesis of a linear precursor using a para-substituted phenylalanine derivative as a starting material. The following intramolecular cyclization reaction was best performed (>73% yield) when Boc-protected linear compound and the condensation reagent, HATU, were simultaneously added to the reaction vessel at the same flow rate. The cyclic compound was then reduced with BH₃ and alkylated with tert-butyl bromoacetate. The synthetic procedure was straightforward and some optimization would be required. However, most of the intermediate compounds were obtained easily in good yields, suggesting that the present synthetic procedure would be useful to synthesize C-ODTA derivatives. The intramolecular cyclization reaction might also be applicable to synthesize polyazamacrocycles of different ring sizes and cyclic peptides. In ¹¹¹In radiolabeling reactions, C-ODTA provided ¹¹¹In chelates in higher radiochemical yields at low ligand concentrations when compared with C-DOTA. The ¹¹¹In-labeled C-ODTA remained unchanged in the presence of apo-transferrin. The biodistribution studies also showed that the ¹¹¹In-labeled compound was mainly excreted into urine as intact. These findings indicate that C-ODTA would be useful to prepare ¹¹¹In-labeled peptides of high specific activities in high radiochemical yields.     

Leishmanicidal activities and cytotoxicities of bisnaphthoquinone analogues and naphthol derivatives from Burman Diospyros burmanica

A methanol extract of the wood of Diospyros burmanica, collected in Burma (Myanmar), was found to exhibit significant activity against Leishmania major. Subsequent chromatographically resolved fractionation led to the isolation of three novel bisnaphthoquinone analogues, burmanin A, B, and C (1-3), together with nine known compounds (4-12). The structure of 1 was confirmed by X-ray crystallography, and those of 2 and 3 by spectroscopic techniques, including 1D and 2D NMR. The inhibitory activities of the isolates were evaluated against the promastigote forms of Leishmania major and the murine macrophage-like cell line, RAW264.7.     

CADLIVE optimizer: web-based parameter estimation for dynamic models

ABSTRACT: Computer simulation has been an important technique to capture the dynamics of biochemical networks. In most networks, however, few kinetic parameters have been measured in vivo because of experimental complexity. We develop a kinetic parameter estimation system, named the CADLIVE Optimizer, which comprises genetic algorithms-based solvers with a graphical user interface. This optimizer is integrated into the CADLIVE Dynamic Simulator to attain efficient simulation for dynamic models.     

The Anti-Inflammatory Effects of Matrix Metalloproteinase-3 on Irreversible Pulpitis of Mature Erupted Teeth

Matrix metalloproteinases (MMPs) are involved in extracellular matrix degradation and the modulation of cell behavior. These proteinases have also been implicated in tissue repair and regeneration. Our previous studies have demonstrated that MMP-3 elicits stimulatory effects on the proliferation and the migration of endothelial cells as well as anti-apoptotic effects on these cells in vitro. In addition, we found that MMP-3 enhanced the regeneration of lost pulp tissue in a rat incisor pulp injury model. However, continuously erupting rodent incisors exhibit significantly different pulp organization compared with mature erupted teeth. Therefore, we have further extended these studies using a canine irreversible pulpitis model to investigate the effects of MMP-3. In this study, the crowns of the canine mature premolars were removed and the pulp tissues were amputated. The amputated pulp tissues remained exposed for 24 or 72 hours to induce mild or severe irreversible pulpitis, respectively, followed by sealing of the cavities. In both models, the whole pulp tissues became necrotic by day 14. In this mild pulpitis model, the regeneration of pulp tissue with vasculature and nerves was observed until 14 days after sealing with MMP-3, followed by extracellular matrix formation in the regenerated pulp tissues until day 28. The treatment with MMP-3 resulted in a decrease in the number of macrophage and antigen-presenting cells and a significant inhibition of IL-6 expression on day 3. The inhibition of MMP-3 activity abolished these anti-inflammatory effects. Immunofluorescence staining demonstrated that MMP-3 was involved in the modification of serum-derived hyaluronan-associated proteins and hyaluronan (SHAP-HA) complexes possibly through the degradation of versican. These results demonstrate that MMP-3 can act as an anti-inflammatory agent and suggest that MMP-3 might represent a useful therapy for the treatment of mild irreversible pulpitis.     

A Novel Rabbit Immunospot Array Assay on a Chip Allows for the Rapid Generation of Rabbit Monoclonal Antibodies with High Affinity

Antigen-specific rabbit monoclonal antibodies (RaMoAbs) are useful due to their high specificity and high affinity, and the establishment of a comprehensive and rapid RaMoAb generation system has been highly anticipated. Here, we present a novel system using immunospot array assay on a chip (ISAAC) technology in which we detect and retrieve antigen-specific antibody-secreting cells from the peripheral blood lymphocytes of antigen-immunized rabbits and produce antigen-specific RaMoAbs with 10^–12 M affinity within a time period of only 7 days. We have used this system to efficiently generate RaMoAbs that are specific to a phosphorylated signal-transducing molecule. Our system provides a new method for the comprehensive and rapid production of RaMoAbs, which may contribute to laboratory research and clinical applications.     

Characterization of PDF-immunoreactive neurons in the optic lobe and cerebral lobe of the cricket, Gryllus bimaculatus

Pigment-dispersing factor (PDF) is a neuropeptide playing important roles in insect circadian systems. In this study, we morphologically and physiologically characterized PDF-immunoreactive neurons in the optic lobe and the brain of the cricket Gryllus bimaculatus. PDF-immunoreactivity was detected in cells located in the proximal medulla (PDFMe cells) and those in the dorsal and ventral regions of the outer chiasma (PDFLa cells). The PDFMe cells had varicose processes spread over the frontal surface of the medulla and the PDFLa cells had varicose mesh-like innervations in almost whole lamina, suggesting their modulatory role in the optic lobe. Some of PDFMe cells had a hairpin-shaped axonal process running toward the lamina then turning back to project into the brain where they terminated at various protocerebral areas. The PDFMe cells had a low frequency spontaneous spike activity that was higher during the night and was often slightly increased by light pulses. Six pairs of PDF-immunoreactive neurons were also found in the frontal ganglion. Competitive ELISA with anti-PDF antibodies revealed daily cycling of PDF both in the optic lobe and cerebral lobe with an increase during the night that persisted in constant darkness. The physiological role of PDF is discussed based on these results.