论文部分内容阅读
This study investigated the composition of long-chain alkyl diols,triols,sec-alcohols,hydroxyl acids,and other hydroxylated compounds in Azolla imbricata and compared the organic alcohol components of Azolla filiculoides,Azolla microphylla,and South China Sea(SCS)sediments in order to investigate the possible indication of Azolla being the biological source of diols and triols in SCS sediment.Large amounts of diols,monohydroxy acids,and sec-alcohols with internal hydroxy groups atω20 were detected in the three types of Azolla.Among these,1,ω20-diol andω20-hydroxy acid exhibited strong even-odd predominance distribution,whereasω20-sec-alcohol exhibited strong odd-even predominance distribution.In addition,small amounts of diols,triols,and dihydroxy acids with internal hydroxy groups at 9,10 orω9,ω10 were detected,among which the chain length of C_(29)was predominate.Compounds having similar structures as those in Azolla reflected a similar biosynthetic pathway:ω20-hydroxy acid exhibiting even-odd predominance distribution is decarboxylated toω20-sec-alcohol exhibiting odd-even predominance distribution and converted to 1,ω20-diol with even-odd predominance distribution by acyl reduction;ω9,ω10-hydroxy acid is converted to 1,20,21(1,ω9,ω10)-triol by acyl reduction,and then converted to 9,10-diol by hydrogenation and dehydration.The alcohol components in A imbricata were clearly not the biological source of 1,13/1,14/1,15-C_(28,30,32)diols and 1,3,4-C_(27-29)triols in the SCS sediment.Certain marine diatoms might be the source of 1,14-C_(28,30)diol in inshore sediment,but the biological source of diols and triols in the SCS sediment requires further investigation.
This study investigated the composition of long-chain alkyl diols, triols, sec-alcohols, hydroxyl acids, and other hydroxylated compounds in Azolla imbricata and compared the organic alcohol components of Azolla filiculoides, Azolla microphylla, and South China Sea (SCS) sediments in order to investigate the possible indication of Azolla being the biological source of diols and triols in SCS sediment. Largest amounts of diols, monohydroxy acids, and sec-alcohols with internal hydroxy groups at ω20 were detected in the three types of Azolla. Among these, 1 , ω20-diol and ω20-hydroxy acid expressed strong even-odd predominance distribution, while ω20-sec-alcohol-rich strong odd-even predominance distribution. In addition, small amounts of diols, triols, and dihydroxy acids with internal hydroxy groups at 9,10 orω9, ω10 were detected, among which the chain length of C_ (29) was predominate.Compounds having similar structures as those in Azolla reflected a similar biosynthetic pathway: ω20-hydroxy acid ex hibiting even-odd predominance distribution is decarboxylated to ω20-sec-alcohol exhibiting odd-even predominance distribution and converted to 1, ω20-diol with even-odd predominance distribution by acyl reduction; ω9, ω10-hydroxy acid is converted to 1,20, 21 (1, ω9, ω10) -triol by acyl reduction, and then converted to 9,10-diol by hydrogenation and dehydration.The alcohol components in A imbricata were clearly not the biological source of 1, 13/1, 14/1 , 15-C_ (28,30,32) diols and 1,3,4-C_ (27-29) triols in the SCS sediment. Maritime marine diatoms might be the source of 1,14-C_ (28,30) diol in inshore sediment, but the biological source of diols and triols in the SCS sediment requires further investigation.