Occurrence of a New Lipoxygenase Isoenzyme in Germinating Barley Embryos

Partially purified preparations of lipoxygenase from the germinating barley embryos converted linoleic acid to 9- and 13-hydroperoxy linoleic acids in the ratio of approximately 3:1, while the similar preparations from the ungerminated embryos converted linoleic acid mainly to 9-hydroperoxy linoleic acid.

Isoelectric focusing of the partially purified preparations of the germinating embryos revealed the presence of the two lipoxygenase active peaks, having isoelectric point at pH 4.9 and 6.6, respectively. The former peak (barley lipoxygenase-1) was identical to lipoxygenase of the ungerminated embryos, but the latter peak (barley lipoxygenase-2) was found only in the germinating embryos. The newly found isoenzyme, barley lipoxygenase-2, converted linoleic acid mainly to 13-hydroperoxy linoleic acid, and could oxidize esterified derivatives of linoleic acid (methyl linoleate and trilinolein) much strongly than barley lipoxygenase-1.     

滇南8种珍贵香科植物的开发利用

在云南热区发掘和初步引种栽培结果的8种野生香料植物,为珍贵资源。从它们的利用部位花、果、叶和根中,可提取芳香油,主要成分分别为芳樟醇、香叶醇、金合欢醇、黄樟素、柠檬醛、茴香醚及癸醛、十二碳醛等,含量相当高,为重要调香原料,有的作药用,颇具发展种植和开发利用价值。