Kiyoshige Ochi

Metabolism of 1α-hydroxyvitamin D3 to 1α,25-dihydroxyvitamin D3 in perfused rat liver

Abstract The metabolism of 1α-hydroxyvitamin D3 (1α-OH-D3) was studied in rat liver perfused with [3H]-1α-OH-D3. [3H]-1α-OH-D3 was converted very rapidly to a more polar metabolite, which was identified as 1α,25-dihydroxy-vitamin D3 [1α,25-(OH)2-D3] by co-chromatography with synthetic 1α,25-(OH)2-D3 as well as by gas chromatography-mass spectrometry. [3H]-1α,25-(OH)2-D3 appeared in the perfusate as early as 20 min after addition of [3H]-1α-OH-D3, and its level in the perfusate increased linearly for at least 120 min. These data strongly indicate that 1α-OH-D3 is metabolized to 1α,25-(OH)2-D3, which exerts biological effects on bone and intestine.

Synthetic Studies on Vitamin D Analogues VI. A New Synthesis of 25-Hydroxycholesterol from Lithocholic Acid

Abstract The conversion of lithocholic acid (1) into 25-hydroxycholesterol (10) via methyl 3β-hydroxy-5-cholenate (6) is described.

Stereocontrolled synthesis of steroid side chain; stereoselective syntheses of cholesterol and 25-hydroxycholesterol

Abstract Novel stereoselective method to introduce side chain onto 17-oxosteroids has been deviced, and using the method cholesterol and 25-hydroxycholesterol are synthesized.

Synthesis and immunoregulating activity of vitamin D analogues bearing pregnane side chains

Abstract The synthesis of Vitamin D analogues bearing pregnane side chains and their immunoregulating activity in mice are described.

Chemistry of Sucralfate

Sulfated polysaccharides possess antiulcer effects in experimental ulcer models and antipeptic activity in vitro. The efficacy of natural polysaccharide is closely related to the degree of the sulfation rather than the length of the sugar chain. Therefore, Namekata and co-workers investigated the antiulcer activities of the oligo- and monosaccharide sulfates whose sugar chain structures are well-known.1

Novel procedure for the preparation of 1α,3β-dihydroxy-2β-tritiated steroidal compounds

Abstract A novel procedure for the preparation of 1α,3β-dihydroxy-2β-tritiated steroidal compounds by the reduction of the α-epoxide with sodium horotritiide in diglyme at 80 C is described.

Synthetic studies of vitamin D3 analogues from bile acids. Part 3. Syntheses of 1α,25-, 1α,24R-, and 1α,24S-dihydroxycholecalciferols from lithocholic acid and their biological activities

Syntheses of 1α,25-, 1α,24R-, and 1α,24S-dihydroxycholecalciferols from lithocholic acid via the analogous 1,4,6-trien-3-ones by application of Kanekos procedure are described. A new synthesis of 1α,25-dihydroxycholecalciferol from lithocholic acid via the 1,4-dien-3-one is also reported. The biological activities of the three cholecalciferols were tested.

Synthesis of 1α-[2-3H]Hydroxyvitamin D3

1α-[2-3H]Hydroxyvitamin D3 was synthesized chemically. The preparation was radiochemically pure and had a high enough specific activity (4.2 Ci/mmol) to permit experiments using 62.5 pmol/rat. This preparation had as much effect as synthetic 1α-hydroxyvitamin D3 in increasing the serum Ca level of vitamin D-deficient rats.

Synthetic studies of vitamin D3 analogues from bile acids. Part 2. Syntheses of cholesta-1,4-dien- and -1,4,6-trien-3-ones having a 24-and/or 25-hydroxylated side chain from lithocholic acid

Syntheses of 3α-hydroxy-5β-cholestanes having a 25-, 24R-, or 24S-hydroxy group [(13), (6a and b)] or a 24,25-dihydroxy group [(14)] from lithocholic acid (1) are described. These hydroxylated cholestanes were converted to the 1,4-dien-3-ones (15), (10a and b), and (16), and then to the 1,4,6-trien-3-ones (18), (11a and b), and (19) by normal dehydrogenation procedures without affecting the side chains.

Synthesis of desmosterol and epidesmosterol from hyodeoxycholic acid

A new synthesis of desmosterol was described using hyodeoxycholic acid (3alpha,6alpha-dihydroxy-5beta-cholanic acid) as a starting material. Epidesmosterol (3alpha-hydroxycholesta-5,24-diene) was also synthesized for the first time from the same starting material.