复合微生物菌群接力发酵结合二维液相色谱法探索茯砖茶中的黄烷-3-醇B环裂环内酯类物质

As the critical bio-active compounds in Fuzhuan brick-tea, flavan-3-ol B-ring fission lactones (FBFLs) are generated during fungal fermentation process, which is a complex dynamic metabolism of a huge number of mixed fungi. In this project, the complex fungal fermentation process is divided into several critical fermentation stages, which will be simulated in corresponding solid state fermentation (SSF) stages in medium, respectively and successively. The fermentation products will be monitored by two dimensional high (or ultra) performance liquid chromatography, to ensure the similarities with those in the corresponding tea bricks, and will be identified by a series of techniques, i.e. organic solvent extraction, chromatographic separation, and spectroscopic elucidation. The drafted project will try to prove that the bio-active compounds are generated by relay fermentation of complex microorganism communities in Fuzhuan brick-tea, by identifying all FBFLs in each critical fermentation stage. In addition, the relationship will be demonstrated between generation process of FBFLs, and fermentation process of complex fungi communities in all stages. This project is critical for discovering more bio-active compounds from the tea, and studying chemecology in fungal fermentation of Fuzhuan brick-tea, as well as improving the manufacture chemistry of dark tea.

黄烷-3-醇B环裂环内酯（FBFLs）是茯砖茶中的关键活性成分群，且其形成过程与茯砖茶发花工序有关。发花是复合微生物的复杂而动态的生长代谢过程。本项目首次提出将此过程分解为数个关键发酵阶段，并用固态培养基分阶段发酵进行模拟。各阶段培养基发酵产物与相应发花茶砖内含成分的一致性将通过二维液相色谱系统来保障，并用天然产物化学的提取分离和光谱解析的方法来鉴定这些产物的化学结构。本项目将系统地探索茯砖茶发花各阶段产生的FBFLs结构，以期证明茯砖茶的活性成分形成于复合微生物的接力发酵过程，并从化学角度初步阐明其形成过程与茯砖茶内复合微生物生长各阶段间的联系，为茯砖茶中活性成分的开发，及茯砖茶发花过程的化学生态学研究和进一步完善黑茶制造化学理论奠定基础。

茯砖茶的发花是固态发酵的过程，也是其风味品质和功能活性形成的关键阶段。该阶段的本质是茶砖中的冠突散囊菌产生自身的代谢物和修饰茶叶原有化学成分，从而改变茶砖内化学轮廓的过程。本项目通过真菌和细菌菌株的分离培养、16S和ITS扩增子测序、基于质谱分子网络的代谢组学、以及天然产物分离与鉴定技术等方法，对茯砖茶发花过程的微生物组、代谢组变化进行了较系统的考察。项目首先从茯砖茶中发现了两个新的酰化黄铜糖苷类化合物。其在体外显示了较强的抗乳腺癌细胞和治疗阿尔茨海默病的效果；其次发现了茯砖茶发花过程在化学轮廓变化上的规律，并通过微生物组学研究初步阐明了其化学轮廓的变化机制。该研究是执行人在上一个国家自然科学青年基金的基础上的延续工作。连续两个基金在该领域内的研究，使得执行人及课题组成员对茯砖茶乃至其他黑茶的功能及风味形成于其加工过程之间的联系有了更深入的理解。这对于其他发酵食品的研究都将产生积极的启示。