Gravity-Based Precise Cell Manipulation System Enhanced by In-Phase Mechanism.

This paper proposes a gravity-based system capable of generating high-resolution pressure for precise cell manipulation or evaluation in a microfluidic channel. While the pressure resolution of conventional pumps for microfluidic applications is usually about hundreds of pascals as the resolution of their feedback sensors, precise cell manipulation at the pascal level cannot be done. The proposed system successfully achieves a resolution of 100 millipascals using water head pressure with an in-phase noise cancelation mechanism.

Cloning of the biosynthetic gene cluster for naphthoxanthene antibiotic FD-594 from Streptomyces sp. TA-0256.

FD-594 is an unique pyrano[4',3':6,7]naphtho[1,2-b]xanthene polyketide with a trisaccharide of 2,6-dideoxysugars. In this study, we cloned the FD-594 biosynthetic gene cluster from the producer strain Streptomyces sp. TA-0256 to investigate its biosynthesis.

Cloning and characterization of the biosynthetic gene cluster of 16-membered macrolide antibiotic FD-891: involvement of a dual functional cytochrome P450 monooxygenase catalyzing epoxidation and hydroxylation.

FD-891 is a 16-membered cytotoxic antibiotic macrolide that is especially active against human leukemia such as HL-60 and Jurkat cells. We identified the FD-891 biosynthetic (gfs) gene cluster from the producer Streptomyces graminofaciens A-8890 by using typical modular type I polyketide synthase (PKS) genes as probes. The gfs gene cluster contained five typical modular type I PKS genes (gfsA, B, C, D, and E), a cytochrome P450 gene (gfsF), a methyltransferase gene (gfsG), and a regulator gene (gfsR).

The cytotoxic macrolide FD-891 induces caspase-8-dependent mitochondrial release of cytochrome c and subsequent apoptosis in human leukemia Jurkat cells.

The 16-membered macrolide FD-891 exerts cytotoxicity toward several cancer cell lines. In this study, we showed that FD-891 induces apoptosis in various human cancer cell lines. Human leukemia Jurkat cells were highly sensitive to FD-891, exhibiting caspase activation and mitochondrial release of cytochrome c into the cytosol at early time points after exposure to FD-891.

Total synthesis and determination of the absolute configuration of FD-838, a naturally occurring azaspirobicyclic product.

The first asymmetric total synthesis of FD-838, a naturally occurring azaspirobicyclic product, has been accomplished allowing determination of its absolute stereochemistry.

Stereostructure of a novel cytotoxic 18-membered macrolactone antibiotic FD-891.

The absolute stereochemistry of FD-891, a novel cytotoxic 18-membered macrolactone antibiotic, was determined by a synthetic approach as well as X-ray diffraction of degradative derivatives. The absolute configuration of FD-891 turned out to be as shown above. The stable conformer of FD-891 was also discussed with respect to biological activity by comparison with the structurally related concanamycin A on the bases of molecular mechanics calculations.

A novel neuritogenic compound, NGA0187.

A new neuritogenic compound NGA0187 was isolated from the fermentation broth of Acremonium sp. TF-0356. The structure of NGA0187 was determined by means of spectroscopic analysis and X-Ray diffraction.

Unique Solvent-Dependent Atropisomerism of a Novel Cytotoxic Naphthoxanthene Antibiotic FD-594.

The absolute stereochemistry of FD-594 1, a new cytotoxic antibiotic, was determined by X-ray diffraction, and its conformation was studied by CD and NMR spectroscopy. The aglycon part of 1 was found to have (3R,6S,7S) configuration. Particularly interesting was the solvent-dependent atropisomerism of 1 and related compounds.

Atypical plexiform ameloblastoma with dentinoid: adenoid ameloblastoma with dentinoid.

In this study, we report a tumor that resembled previously reported uncommon tumors histologically similar to ameloblastoma or adenomatoid odontogenic tumor (AOT), showing the formation of hard tissue. We evaluated the histological characteristics by reviewing the literature. The patient was a 19-year old male.

Influenza virus RNA polymerase PA subunit is a novel serine protease with Ser624 at the active site.

Background: Influenza virus RNA polymerase is a multifunctional enzyme that catalyses both transcription and replication of the RNA genome. The function of the influenza virus RNA polymerase PA subunit in viral replication is poorly understood, although the enzyme is known to be required for cRNA --> vRNA synthesis. The protease related activity of PA has been discussed ever since protease-inducing activity was demonstrated in transfection experiments.

Synthesis of NG-061 and its analogs, and their biological evaluation as an enhancer of nerve growth factor.

A novel potentiator of nerve growth factor (NGF), NG-061, which had been isolated from the fermentation broth of Penicillium minioluteum F-4627, was synthesized from methoxybenzoquinone and phenylacetylhydrazine in a single step. A series of acyl hydrazone derivatives were also synthesized and their potentiator activity of neurotrophic effect of NGF on neurite outgrowth was evaluated by assay with a rat pheochromocytoma cell line PC12.

FD-891, a structural analogue of concanamycin A that does not affect vacuolar acidification or perforin activity, yet potently prevents cytotoxic T lymphocyte-mediated cytotoxicity through the blockage of conjugate formation.

FD-891 belongs to a group of 18-membered macrolides, and is a structural analogue of a specific inhibitor of vacuolar type H+-ATPase, concanamycin A (CMA). In our previous work, we have shown that CMA specifically inhibits perforin-dependent cytotoxic T lymphocyte (CTL)-mediated cytotoxicity through the degradation and inactivation of perforin, although CMA does not affect Fas ligand (FasL)-dependent cytotoxicity. Here, we show that FD-891 potently prevents not only perforin-dependent but also FasL-dependent CTL-mediated killing pathways by blocking CTL-target conjugate formation.

Structural basis of inhibition of cysteine proteases by E-64 and its derivatives.

This paper focuses on the inhibitory mechanism of E-64 and its derivatives (epoxysuccinyl-based inhibitors) with some cysteine proteases, based on the binding modes observed in the x-ray crystal structures of their enzyme-inhibitor complexes. E-64 is a potent irreversible inhibitor against general cysteine proteases, and its binding modes with papain, actinidin, cathepsin L, and cathepsin K have been reviewed at the atomic level. E-64 interacts with the Sn subsites of cysteine proteases.

Structure of NG-061, a novel potentiator of nerve growth factor (NGF) isolated from Penicillium minioluteum F-4627.

The structure of NG-061, a new potentiator of nerve growth factor (NGF) isolated from Penicillium minioluteum F-4627, was determined by spectroscopic analysis and X-ray diffraction method to be phenylacetic acid 2-(2-methoxy-4-oxocyclohexa-2,4-dienylidene)-hydrazide.

A novel fungal metabolite NG-061 enhances and mimics neurotrophic effect of nerve growth factor (NGF) on neurite outgrowth in PC12 cells.

During the course of our screening program for low molecular natural products with their ability to potentiate and/or mimic neurotrophic effect of NGF, a novel fungal metabolite, phenylacetic acid hydrazide derivative NG-061 was isolated from the fermentation broth of Penicillium minioluteum F-4627. NG-061 enhanced and mimicked neurotrophic effect of NGF on neurite outgrowth in a rat pheochromocytoma cell line PC12.

Structure and biosynthesis of FD-594; a new antitumor antibiotic.

The structure of a novel antitumor antibiotics FD-594 (1), produced by Streptomyces sp. TA-0256, was determined to have a glycosylated pyrano[4',3':6,7]naphtho[1,2-b]-xanthene skeleton by means of spectral data. The biosynthetic studies of the chromophore of 1 was also carried out by feeding experiments with [1-13C]-, [2-13C]-, and [1,2-13C2]sodium acetate.

Isolation and characterization of a new pyrano[4',3':6,7]naphtho[1,2-b]xanthene antibiotic FD-594.

During our screening of microbial metabolites for effective drugs against tumor cell lines, we discovered a new pyrano[4',3':6,7]naphtho[1,2-b]xanthene derivative, FD-594 from the fermentation broth of Streptomyces sp. TA-0256. FD-594 shows moderate activity against tumor cell lines, comparative to that of adriamycin, as well as antibacterial activity against some Gram-positive bacteria.

X-ray crystal structure of papain complexed with cathepsin B-specific covalent-type inhibitor: substrate specificity and inhibitory activity.

The Ile-Pro sequence of CA074, potent covalent-type inhibitor, is necessary to exhibit the specificity for cathepsin B, but not for papain. In order to elucidate how its sequence binds to papain and why such binding does not exhibit the specificity for papain at the atomic level, two CA074-related compounds, 1 (N-(L-3-carboxyloxirane-2-carbonyl)-L-isoleucyl-L-proline) and 2 (N-(L-3-carboxyloxirane-2-carbonyl)-L-isoleucyl-diethylamide), were designed and their structure--inhibitory activity relationship was investigated by the X-ray crystal analyses of the complexes with papain. The Ile-Pro moiety of 1 was located at the S2 and S3 subsites consisting of Val-133, Val-157, and Asp-158 and of Tyr-61, Gly-66, and Tyr-67 residues of papain, respectively, which is in contrast with the binding of CA074 to S'n (n = 1 approximately 2) subsites in the complex with cathepsin B.

Stachybotrin C and parvisporin, novel neuritogenic compounds. II. Structure determination.

The structures of stachybotrin C and parvisporin have been determined by spectroscopic analyses and chemical derivatization. Stachybotrin C contains a unique pyrano-isoindolinone ring system, while parvisporin has a hydroxyl farnesyl phenol structure.

Stachybotrin C and parvisporin, novel neuritogenic compounds. I. Taxonomy, isolation, physico-chemical and biological properties.

Stachybotrin C and parvisporin, novel neuritogenic compounds, were isolated from the culture broth of Stachybotrys parvispora F4708. Stachybotrin C induced significant neurite outgrowth in PC12 cells and showed cell survival activity in the primary culture of cerebral cortical neurons. Parvisporin demonstrated only weak neuritogenic activity.

Microbial glycosylation of macrolide antibiotics by Streptomyces hygroscopicus ATCC 31080 and distribution of a macrolide glycosyl transferase in several Streptomyces strains.

In the course of our microbial transformation study on erythromycin derivatives, Streptomyces hygroscopicus ATCC 31080, which produces a polyether antibiotic carriomycin, was found to transform erythromycin derivatives to their inactivated derivatives. The structures of inactivated derivatives prepared by enzyme reaction using the cell extract, UDP-glucose (or UDP-galactose) and Mg2+ (or Mn2+) were elucidated on the basis of analysis of thei spectral data to be the compounds glycosylated at C-2' of a desosamine moiety, indicating that the enzyme is a macrolide glycosyl transferase (MGT). The MGT activity of cell extract from S.

A new isopatulin derivative pintulin produced by Penicillium vulpinum F-4148 taxonomy, isolation, physico-chemical properties, structure and biological properties.

During our screening program of natural products from fungal metabolites for drugs effective against tumor cell lines, we discovered a new isopatulin derivative, pintulin, from the fermentation broth of Penicillium vulpinum F-4148. Pintulin shows weak activity against tumor cell lines, compared to that of adriamycin.

Cytotoxic cardenolides from woods of Euonymus alata.

Three cytotoxic cardenolides, acovenosigenin A 3-O-alpha-L-ramnopyranoside (1), euonymoside A (2) and euonymusoside A (3), were isolated from the woods of Euonymus alata (Celastraceae). The chemical structure of a new cardenolide, euonymusoside A (3) has been elucidated on the basis of extensive spectral analysis and enzymic hydrolysis to be acovenosigenin A (1 beta, 3 beta, 14 beta-trihydroxy-5 beta-cardenolide) 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranoside. All three showed potent cytotoxic activity against some neoplastic cell lines.