Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Phytochemistry. 2011 Dec;72(18):2342-51. doi: 10.1016/j.phytochem.2011.08.017. Epub 2011 Sep 10.
The yellow-green alga Trachydiscus minutus (Eustigmatophyceae, Heterocontophyta) was cultivated in a standard medium and under nitrogen- and phosphorus-starvation and its triacylglycerols were analyzed by RP-HPLC/MS-APCI. The molecular species of triacylglycerols included a total of 74 triacylglycerols having at least one polyunsaturated fatty acid. Polyunsaturated triacylglycerols were identified for the first time in a yellow-green alga. N-starvation brought about a nearly 50% drop in TAGs containing EPA, and also decreased TAGs containing ARA, while P-starvation had a sizable effect on those TAGs that contain two or three arachidonic acids. In four TAGs containing PUFA, i.e. EEE, EEA, EAA and AAA, N-starvation caused a rapid fivefold increase in ARA content and the ratio of TAGs containing ARA, i.e. AEE to AAA increased tenfold relative to control. Regioisomeric characterization of triacylglycerols containing palmitic, arachidonic (ARA) and eicosapentaenoic acids (EPA) showed that the proportion of positional isomers is affected by N- and P-starvation. N- and P-starvation also changed the ratio of symmetrical to asymmetrical TAGs. Positional isomers exhibited identical ratios of symmetrical and asymmetrical TAGs irrespective of the type of FAs. In control cultivation the major TAGs with a single PUFA were symmetrical ones (PEP or PAP) whose ratio to asymmetrical counterparts (PPE or PPA) was about 3:1, whereas N- and P-starvation yielded opposite ratios, 1:3-1:5. The control cultivation yielded ~90% asymmetrical TAGs with two PUFAs (i.e. PEE and PAA), whereas with N- and P-starvation the ratio of symmetrical to asymmetrical TAGs increased to 2:1 and 3:2, respectively.
小球藻（Eustigmatophyceae，Heterocontophyta）在标准培养基中以及氮磷饥饿条件下培养，并通过反相高效液相色谱/质谱-大气压化学电离（RP-HPLC/MS-APCI）分析其三酰基甘油。三酰基甘油的分子种类包括至少含有一种多不饱和脂肪酸的总共 74 种三酰基甘油。多不饱和三酰基甘油首次在一种黄-绿藻中被鉴定出来。氮饥饿导致含有 EPA 的三酰基甘油几乎减少了 50%，同时也降低了含有 ARA 的三酰基甘油，而磷饥饿对含有两个或三个花生四烯酸的三酰基甘油有相当大的影响。在含有多不饱和脂肪酸的四种三酰基甘油（即 EEE、EEA、EAA 和 AAA）中，氮饥饿导致 ARA 含量迅速增加五倍，且含有 ARA 的三酰基甘油（即 AEE 与 AAA）的比例相对于对照增加了十倍。含有棕榈酸、花生四烯酸（ARA）和二十碳五烯酸（EPA）的三酰甘油的区域异构体特征表明，位置异构体的比例受氮磷饥饿的影响。氮磷饥饿还改变了对称三酰甘油与不对称三酰甘油的比例。无论 FAs 的类型如何，位置异构体都表现出相同的对称和不对称三酰甘油的比例。在对照培养中，单一多不饱和脂肪酸的主要三酰甘油是对称的（PEP 或 PAP），其与不对称对应物（PPE 或 PPA）的比例约为 3:1，而氮磷饥饿产生相反的比例，1:3-1:5。对照培养产生约 90%的不对称含有两个多不饱和脂肪酸（即 PEE 和 PAA）的三酰甘油，而氮磷饥饿使对称三酰甘油与不对称三酰甘油的比例分别增加到 2:1 和 3:2。
