Junei Kinjo

AIDS dementia: Synthesis and properties of a derivative of 3′‐azido‐3′‐deoxythymidine (AZT) that may become ‘locked’ in the central nervous system

In an attempt to provide a derivative of 3′‐azido‐3′‐deoxythymidine (AZT) which might be sequestered in the central nervous system and release AZT, the dihydropyridine ester 5′‐(1,4‐dihydro‐1‐methyl‐3‐pyridinylcarbonyl)‐3′‐deoxythymidine, was synthesized in a three step sequence. This material showed potent anti‐HIV‐1 activity in MT‐4 cells most probably by hydrolysis to the parent nucleoside, AZT. This dihydropyridine derivative of AZT could be easily oxidized to a positively charged pyridinium derivative of AZT in rat brain cytosol. In turn the pyridinium form could be hydrolyzed, non‐enzymatically, to AZT.

Novel yellow pigment from Pterocarpus santalinus: Biogenetic hypothesis for santalin analogs☆

A novel yellow pigment named santalin Y, related to red pigment santalin A was isolated from Pterocarpus santalinus. Its structure was determined by various spectral data including X-ray analysis. Biogenetic relationships for these compounds were also discussed.

Studies on leguminous plants. Part XXXIV. Six New Triterpenoidal Glycosides Including Two New Sapogenols from Albizziae Cortex. V.

Six new triterpenoid glycosides called julibrosides A1-A4, B1 and C1 were isolated from Albizziae Cortex, the dried stem bark of Albizzia julibrissin Durazz. Their structures were determined based on spectral and chemical evidence. Julibrosides B1 and C1 had new sapogenols, designated julibrogenin B and C, respectively, while julibrosides A3 included N-acetyl-D-glucosamine as a sugar component.

Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 microg/ml. Coumarins with a cyclized gamma,gamma-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 microg/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

Four monoterpene alkaloid derivatives from Incarvillea sinensis

Two new derivatives of monoterpene alkaloids, named incarvillateine C and incarvillateine D which are related to an antinociceptive alkaloid, incarvillateine, were isolated from the aerial parts of Incarvillea sinensis LAM. On the basis of both chemical and spectroscopic evidence, the structures of the first two were characterized as a bis-demethoxy and demethoxy derivatives of incarvillateine, respectively.

Onionin A from Allium cepa inhibits macrophage activation.

Onionin A (1), a new, stable, sulfur-containing compound, was isolated from acetone extracts of bulbs of onion (Allium cepa), and its structure was characterized as 3,4-dimethyl-5-(1E-propenyl)-tetrahydrothiophen-2-sulfoxide-S-oxide, on the basis of the results of spectroscopic analysis. This compound showed the potential to suppress tumor-cell proliferation by inhibiting the polarization of M2 alternatively activated macrophages.

Pharmacological Studies on Puerariae flos III: Protective Effects of Kakkalide on Ethanol‐induced Lethality and Acute Hepatic Injury in Mice

Kakkalide, one of the major isoflavonoid components of Puerariae flos, has been investigated for its effect on ethanol‐induced intoxication and on hepatic injury, including hyperglycaemia, in mice.

But-2-enolides from Pueraria lobata and revised structures of puerosides A, B and sophoroside A

Abstract From the roots of Pueraria lobata , two aromatic compounds have been obtained and their chemical structures have been characterized as but-2-enolides. In connection with this result, it has become apparent that the previous structures for pucrosides A, B and sophoroside A should be revised to related but-2-enolides.

Microbial transformation and bioactivation of isoflavones from Pueraria flowers by human intestinal bacterial strains

The flowers from Pueraria, which are called Puerariae Flos, have been used since ancient times for recovery from alcohol intoxication. We elucidated the microbial transformation of the main isoflavones (1, 1a and 2) by using 29 commercially available human intestinal bacterial strains together with the bioactivation of the hepatoprotective activity of their metabolites. Tectoridin (1a), which contains only one glucosyl moiety, was metabolized to its aglycone 1b by various bacterial strains. On the other hand, the metabolism of 1 and 2, which both have disaccharide groups, was limited to specific bacterial strains. The metabolites 1c and 2c obtained from the Peptostreptococcus productus strain were completely different from those produced by the other strains. These metabolites were identified as 6-hydroxygenistein and 6-hydroxybiochanin A, respectively. The glycosides 1, 1a and 2 did not show any hepatoprotective activity, whereas aglycones 1b and 2b showed moderate activity. Furthermore, the hepatoprotective activity of the demethylated metabolites 1c and 2c was extremely potent. Although not all people have P. productus in their gastrointestinal tract, the O-demethylated compounds might become one of the bioactivated metabolites when Puerariae Flos is administered orally.

Antinociceptive substances from Incarvillea delavayi

Antinociceptive activities of an Incarvillea delavayi extract, as well as its constituents, 8-epideoxyloganic acid and delavayine A, were evaluated in the acetic acid induced writhing test in mice. An oral administration of the delavayi extract weakly decreased the number of writhings and stretchings in this test, in a dose-dependent manner. Furthermore, orally administered 8-epideoxyloganic acid showed weak antinociceptive activity, whereas administration by subcutaneous injection did not. However, subcutaneous injection of delavayine A, a novel monoterpene alkaloid, showed a more significant level of antinociceptive activity.