New triterpenes from a Chinese medicine, goreishi

Besides serratagenic acid, three new ursane-type triterpenes, named goreishic acids I (1), II (2), and III (3), were isolated from a Chinese medicine, Goreishi (the feces of Trogopterus xanthipes Milne-Edwards). The structures of 1, 2 and 3 were respectively determined as 2 alpha,3 beta-dihydroxyursa-12,18-dien-28-oic acid, 2 alpha,3 beta-dihydroxy-23-norursa-12,18-dien-28-oic acid and 2 alpha,3 beta-dihydroxy-24-norursa-12,18-dien-28-oic acid on the basis of spectroscopic evidence.     

Total synthesis of tylosin

Tylosin has been synthesized byregio- and stereoselective introduction of the amino disaccharide moiety and D-mycinose onto the previously synthesized 16-membered-ring aglycone.     

Semidifferential electroanalysis with a solid working electrode

Semidifferential electroanalysis is described for hexacyanoferrate(III), dichromate, copper(II), p-aminophenol, p-benzoquinone, m-dinitrobenzene, guanine, guanosine, adenine, and adenosine at a stationary solid working electrode. Nearly symmetrical, peaked curves are obtained for the electrode processes of all the samples investigated. The predicted dependence of peak height and peak potential on concentration, electrode area, and potential scan rate are confirmed-experimentally for the glassy carbon disk electrode. It is demonstrated that the technique with the solid working electrode provides higher sensitivity and better resolution than ordinary linear sweep voltammetry. The sensitivity is somewhat worse than in differential pulse voltammetry, but the technique has the advantage of Speed.     

Regional cerebral blood flow measurement in brain tumors

The regional cerebral blood flow (CBF) was determined on seventeen patients with brain tumors. Ring type single photon emission CT (SPECT) was used following intravenous injection of 133Xe. Case materials included eleven meningiomas and six malignant gliomas. Evaluation was performed with emphasis on the following points; Correlation of the flow data within tumors to the angiographic tumor stains, Influence of tumors on the cerebral blood flow of the normal brain tissue, Correlation between degree of peripheral edema and the flow data of the affected hemispheres. There was significant correlation between flow data within tumors and angiographic tumor stains in meningiomas. Influence of tumors on cerebral blood flow of the normal tissue was greater in meningiomas than in gliomas. There was negative correlation between the degree of peripheral edema and the flow data of the affected hemisphere. It has been concluded that the measurement of CBF in brain tumors is a valuable method in evaluation of brain tumors.