Dipartimento di Biologia, Università di Padova, Via Trieste 75, 35121, Padova, Italy.
J Chem Ecol. 1992 Feb;18(2):155-64. doi: 10.1007/BF00993750.
Furocoumarin distribution patterns in the fruits and seeds ofPsoralea macrostachya andP. onobrychis were investigated. Both species contain the linear furocoumarin psoralen and its angular isomer, angelicin. In the monospermous indehiscent fruit ofP. macrostachya, furocoumarins occur in the pericarp and all seed parts. InP. onobrychis, the pericarp of which is easily detached at ripeness, no furocoumarins were found in the pericarp tissues and only traces occur in the embryo axis; cotyledons are the preferential accumulation site. The within-fruit and -seed furocoumarin variations associated with the developmental stages of fruit were followed inP. onobrychis, in view of changes in the defensive value of the pericarp before and after ripening. Rapid furocoumarin biosynthesis after fertilization was observed in both pericarp and seed; ripening is associated with furocoumarin decrease in the seed and complete disappearance in the pericarp tissues. Such findings are consistent with the chemical defense role of these substances. The cooccurrence of linear and angular isomers seems to be a chemical marker of the genusPsoralea: the biosynthetic pathway leading to the angular isomer as an evolutionary response to selective pressure from herbivore insects is suggested.
研究了 Psoralea macrostachya 和 P. onobrychis 果实和种子中的呋喃香豆素分布模式。这两个物种都含有线性呋喃香豆素补骨脂素及其角型异构体花椒毒素。在单室不开裂的 Psoralea macrostachya 果实中，呋喃香豆素存在于果皮和所有种子部分。而 P. onobrychis 的果皮在成熟时很容易脱落，果皮组织中没有发现呋喃香豆素，只有微量存在于胚轴中；子叶是优先积累的部位。鉴于果皮在成熟前后防御价值的变化，研究了 P. onobrychis 中与果实发育阶段相关的果实内和种子内呋喃香豆素的变化。在果皮和种子中都观察到受精后呋喃香豆素的快速生物合成；成熟与种子中呋喃香豆素的减少有关，果皮组织中的呋喃香豆素完全消失。这些发现与这些物质的化学防御作用一致。线性和角型异构体的共存似乎是 Psoralea 属的化学标志：建议将导致角型异构体的生物合成途径作为对草食性昆虫选择压力的进化反应。
