When the plasma mumbrane of the yeast Rhodotorula minuta cells was exposed to near-UV at 0℃, three new compounds were formes photochemically with decrease in ergosterol content. When 0.4%-SDS solution containing ergosterol was illuminated with near-UV, the same three compounds as in the membrane were formed. As a result of instruments analysis, one of three photochemical products was identified as previtamine D2 and another two compounds were characterized chemically that they had the structure of ergosta-4, 7, 22-trein-3-on. In addition, these photochemical products did not affect the growth and carotenogenesis of the yeast Rhodotorulaminuta.赤色酵母R.minuta細胞膜に長波長紫外光を照射した時に生じるエルゴステロール由来の光化学反応生成物の単離・精製およびその同定を行った。結果、3種類の物質が単離・精製され、そのうち1つはPrevitamin D2であることが同定され、残りの2つについてはergosta-4,7,22-trien-3-on の何かの炭素にOH基が付いたものであることが分かった。単離した成分を培地に加え、菌体の増殖とカロテノイド生合成に対する影響を調べた結果、これらの物質はそのどちらにも影響を及ぼさなかった
