[Diffuse infiltrating primary cerebellar glioma involving the brainstem: a case report].

An 85-year-old woman was admitted to our hospital with unsteady gait, dizziness, nausea, and vomiting. MRI revealed characteristic abnormal signals in the bilateral cerebellar hemispheres. A brain biopsy was performed which confirmed a definitive histological diagnosis of diffuse glioma. Follow-up MRI showed diffuse abnormal signals that extended from the cerebellum to the brainstem through the cerebellar peduncle without mass formation. Her general condition gradually deteriorated even with the best supportive care, and she died 195 days after admission. Gliomatosis cerebri is characterized by a diffuse infiltrating growth pattern without mass formation in the brain. This case showed a similar proliferation mode from the cerebellum to the brain stem without mass formation. This case was diagnosed based on MRI and pathological findings. Only five similar cases have been previously reported, and compared to these reports, the patient in the present case was the oldest with the poorest prognosis. The histopathological features may influence the appropriate treatment and the prognosis. This disorder is a very rare condition; thus, when we encountered this patient showing cerebellar ataxia with diffuse abnormal MRI signals without mass formation in the cerebellum and brainstem, a brain biopsy was necessary to establish the definitive diagnosis.

Synthesis and biological activity of ganglioside GM3 analogues with a (S)-CHF-Sialoside linkage and an alkyne tag.

The alkyne tag, consisting of only two carbons, is widely used as a bioorthogonal functional group due to its compactness and nonpolar structure, and various probes consisting of lipids bearing an alkyne tag have been developed. Here, we designed and synthesized analogues of ganglioside GM3 bearing an alkyne tag in the fatty acid moiety and evaluated the effect of the alkyne tag on the biological activity. To eliminate the influence of other factors such as degradation of the glycan chain when evaluating biological activity in a cellular environment, we introduced the tag into sialidase-resistant (S)-CHF-linked GM3 analogues developed by our group. The designed analogues were efficiently synthesized by tuning the protecting group of the glucosylsphingosine acceptor. The growth-promoting effect of these analogues on Had-1 cells was dramatically altered depending upon the position of the alkyne tag.

Ganglioside GM3 Analogues Containing Monofluoromethylene-Linked Sialoside: Synthesis, Stereochemical Effects, Conformational Behavior, and Biological Activities.

Glycoconjugates are an important class of biomolecules that regulate numerous biological events in cells. However, these complex, medium-size molecules are metabolically unstable, which hampers detailed investigations of their functions as well as their potential application as pharmaceuticals. Here we report sialidase-resistant analogues of ganglioside GM3 containing a monofluoromethylene linkage instead of the native O-sialoside linkage. Stereoselective synthesis of CHF-linked disaccharides and kinetically controlled Au(I)-catalyzed glycosylation efficiently furnished both stereoisomers of CHF-linked as well as CF 2 - and CH 2 -linked GM3 analogues. Like native GM3, the C-linked GM3 analogues inhibited the autophosphorylation of epidermal growth factor (EGF) receptor induced by EGF in vitro. Assay of the proliferation-enhancing activity toward Had-1 cells together with NMR-based conformational analysis showed that the (S)-CHF-linked GM3 analogue with exo-gauche conformation is the most potent of the synthesized compounds. Our findings suggest that exo-anomeric conformation is important for the biological functions of GM3.

Total Syntheses of (+)-Marrubiin and (-)-Marrulibacetal.

A stereoselective total synthesis of (+)-marrubiin has been accomplished starting from a chiral building block via the CyNH2-promoted Pauson-Khand reaction (PKR) followed by oxidative cleavage of the resultant cyclopentenone ring. Two successive oxidations and internal transacetalization culminated in the total synthesis of the antispasmodic labdane diterpenoid (-)-marrulibacetal.

Development of a screening system for the evaluation of soybean volatiles.

Flavor properties are important factors of soybean seeds in their utilization as food materials. In order to isolate novel varieties and mutants of soybean having preferable flavor properties, a simple and efficient screening system was established using an automated headspace sampler coupled to gas chromatography. With this system, five major volatile compounds were analyzed within 12 min. By applying this screening system to 626 soybean varieties collected worldwide, we isolated four soybean varieties that showed unique compositions of volatile compounds. Through biochemical analysis, it was found that the uniqueness of three of them was possibly independent of lipoxygenase enzyme, and thus perhaps this screening system can expand the subject of flavor properties beyond lipoxygenase and thus be useful in discovering new types of soybeans.

Synthesis of CH2-linked alpha(2,3)sialylgalactose analogue: on the stereoselectivity of the key Ireland-Claisen rearrangement.

A CH 2 -linked alpha(2,3)sialylgalactose analogue was efficiently synthesized using an Ireland-Claisen rearrangement, which was developed recently by our group for constructing a CF 2 -sialoside. The reaction conditions of the rearrangement were optimized for alpha-stereoselective formation of the CH 2 -sialoside. On the basis of the observed temperature effects, the origin of the stereoselectivity of the Ireland-Claisen rearrangement is discussed. Moreover, reconstruction of the 2alpha-hydroxyl group on the galactose unit of the rearrangement product was achieved by means of stereoselective dihydroxylation and deoxygenation.