An actinomycete, strain YC75T, which produced baf ilomycin-like antifungal compounds, was identified as a member of the genus Kitasatospora on the basis of morphological and chemotaxonomic characteristics. The strain produced the aerial and fragmenting vegetative mycelia consisting of straight chains of 20 or more smooth-surfaced spores. Submerged spores were formed in tryptic soy broth. No soluble pigments were formed. Whole-cell hydrolysates contained glucose and mannose, but not galactose. The 16s rDNA sequence of YC75T was compared with those of the other representative 305-600, Republic ofKorea kitasatosporae and streptomycetes. Strain YC75T formed a significant monophyletic clade with Kitasatospora phosalacinea. The levels of DNA relatedness between strain YC75T and representatives of the genus Kitasatospora ranged from 16 to 59% including K. phosalacinea (28 and 40%). It is clear from polyphasic evidence that the isolate should be classified as Kitasatospora cheerisanensis sp. nov., whose type strain is YC75T (= KCTC 23953. The presence of galactose in whole-cell hydrolysates may not be a stable chemical marker for the genus Kitasatospora.

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AU-461 (1-(2-methyl-4-methoxyphenyl)-4-[(2-hydroxyethyl)amino]-6-β,β,β-trifluoroethoxy-2,3-dihydropyrrolo[3,2-c]quinoline) was tested for its ability to act as an anti-ulcer agent. AU-461 inhibited gastric H⁺/K⁺ ATPase activities with IC₅₀ values of 12.15 and 4.20 μmol/l for rabbit and pig enzymes, respectively. The inhibition was reversible, and competitive with respect to the activating cation K⁺. When AU-461 was examined for the in vivo antisecretory activity, we found that AU-461 reduced the histamine-stimulated acid secretion as well as the basal secretion in rat stomach. Duration of the antisecretory effect was about 6 h upon oral administration. AU-461 prevented dose-dependently the ulcer formation produced by either ethanol or NaOH. This protective effect was not altered by indomethacin pretreatment. In addition, the elevated plasma gastrin by the oral administration of AU-461 was returned to control by 12 h. Taken together, these results suggest that AU-461 could be developed as a new therapeutic agent for peptic ulcer disease.

Anti-ulcer activity of newly synthesized acylquinoline derivatives was investigated. For the in vitro screening, the effects of the compounds on gastric H+/K+ ATPase isolated from hog and rabbit were examined. Among them, AU-090, AU-091, AU-254, AU-413 and AU-466 exhibited good in vitro activity on both enzymes. To correlate the in vitro activity with in vivo action, the effects of the compounds on the basal gastric acid secretion were studied. Some derivatives showed considerable anti-secretory activities, and AU-413 was selected for further studies. AU-413 protected gastric damage induced by either ethanol or NaOH dose dependently when given orally. ED50 values of 12 mg/kg, p.o. (ethanol) and 41 mg/kg, p.o. (NaOH) were obtained. In addition, histamine-stimulated gastric secretion was reduced upon AU-413 administration. Taken together, newly synthesized acylquinoline derivatives, especially AU-413, is worthy of further investigation to be developed as an anti-ulcer agent.