Elucidation of saikosaponin biosynthesis mechanism and saikosaponin production by yeast

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08314
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural medicines
• Research Institution: Tokushima Bunri University
• Principal Investigator: Masaaki Noji 徳島文理大学, 薬学部, 准教授 (80271534)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: サイコサポニン / 生合成 / シトクロムP450

Outline of Final Research Achievements

By searching the EST databases of Bupleurum falcatum L., we have isolated three cDNAs of cytochrome P450, R144574, which hydroxylates the carbon at position 23 of β-amyrin, Rnn9542 hydroxylating C-16β, and CL4443 forming an ether linkage between C-13 and C-28, in addition to R144792 hydroxylating C-28, and Rnn 2525 hydroxylating C-16α, which have so far been identified as the cytochrome P450s involved in saikosaponin biosynthesis. As a consequence, we successfully identified all the cytochrome P450s involved in saikosaponin biosynthesis. Furthermore, as a result of expressing these enzyme genes in yeast, we succeeded in producing saikogenin F, the aglycone of saikosaponin A, which is one of a major saponin of B. falcatum L..

Free Research Field

天然資源系薬学

Academic Significance and Societal Importance of the Research Achievements

サイコサポニン生合成に関与する全てのシトクロムP450を同定することに成功したことで、植物がつくる複雑な二次代謝物の生合成機構の解明が可能となった。またミシマサイコのサイコサポニン生合成に関与する酵素の6遺伝子を酵母内で同時に発現させることに成功した。その結果、ミシマサイコの主要なサポニンであるサイコサポニンAのアグリコンを酵母で生産させることに成功した。このことにより、酵母を用いて植物が産生する有用な代謝物を早く、大量につくりだすための基盤作りに成功したといえる。