Cramer U, Spener F
Eur J Biochem. 1977 Apr 15;74(3):495-500. doi: 10.1111/j.1432-1033.1977.tb11416.x.
In seeds of Hydnocarpus anthelminthica of Flacourtiaceae, cyclopentenylglycine and cyclopentenyl fatty acids are found naturally. The non-proteinogenic amino acid may serve as precursor of cyclopentenyl fatty acids via aleprolic acid, the starter molecule for these long-chain compounds. After administration of cyclopentenyl[2-14C]glycine to maturing seeds of H. anthelminthica, labelled cyclopentenyl fatty acids were synthesized. Comparative activities were observed, when [1-14C]aleprolic acid was supplied to the seeds. Incorporation studies with [1-14C]acetate revealed that the chain-lengthening systems for straight-chain and cyclic fatty acids were still functioning in mature seeds. Endosperm and embryo of H. Anthelminthica seeds synthesized cyclopentenyl fatty acids from cyclopentenyl[2-14C]glycine, [1-14C]aleprolic acid and [1-14C]acetate. In embryonic tissue, a dilution experiment proved the following path for cyclopentenyl fatty acid biosynthesis: cyclopentenylglycine leads to aleprolic acid leads to cyclopentenyl fatty acids. The conversion of cyclopentenylglycine to aleprolic acid may occur via transamination and oxidative decarboxylation; activated aleprolic acid is then lengthened by C2-units to cyclopentenyl fatty acids.
在大风子科印度大风子的种子中，天然存在环戊烯基甘氨酸和环戊烯基脂肪酸。这种非蛋白质氨基酸可能通过麻风油酸作为环戊烯基脂肪酸的前体，麻风油酸是这些长链化合物的起始分子。将环戊烯基[2-¹⁴C]甘氨酸施用于印度大风子成熟种子后，合成了标记的环戊烯基脂肪酸。当向种子提供[1-¹⁴C]麻风油酸时，观察到了比较活性。用[1-¹⁴C]乙酸进行的掺入研究表明，直链和环状脂肪酸的链延长系统在成熟种子中仍在发挥作用。印度大风子种子的胚乳和胚从环戊烯基[2-¹⁴C]甘氨酸、[1-¹⁴C]麻风油酸和[1-¹⁴C]乙酸合成环戊烯基脂肪酸。在胚胎组织中，一项稀释实验证明了环戊烯基脂肪酸生物合成的以下途径：环戊烯基甘氨酸生成麻风油酸生成环戊烯基脂肪酸。环戊烯基甘氨酸向麻风油酸的转化可能通过转氨作用和氧化脱羧作用发生；然后活化的麻风油酸通过C₂单位延长为环戊烯基脂肪酸。
