TMDB: a literature-curated database for small molecular compounds found from tea

Abstract

Background: Tea is one of the most consumed beverages worldwide. The healthy effects of tea are attributed to a wealthy of different chemical components from tea. Thousands of studies on the chemical constituents of tea had been reported. However, data from these individual reports have not been collected into a single database. The lack of a curated database of related information limits research in this field, and thus a cohesive database system should necessarily be constructed for data deposit and further application.

Description: The Tea Metabolome database (TMDB), a manually curated and web-accessible database, was developed to provide detailed, searchable descriptions of small molecular compounds found in Camellia spp. esp. in the plant Camellia sinensis and compounds in its manufactured products (different kinds of tea infusion). TMDB is currently the most complete and comprehensive curated collection of tea compounds data in the world. It contains records for more than 1393 constituents found in tea with information gathered from 364 published books, journal articles, and electronic databases. It also contains experimental 1H NMR and 13C NMR data collected from the purified reference compounds or collected from other database resources such as HMDB. TMDB interface allows users to retrieve tea compounds entries by keyword search using compound name, formula, occurrence, and CAS register number. Each entry in the TMDB contains an average of 24 separate data fields including its original plant species, compound structure, formula, molecular weight, name, CAS registry number, compound types, compound uses including healthy benefits, reference literatures, NMR, MS data, and the corresponding ID from databases such as HMDB and Pubmed. Users can also contribute novel regulatory entries by using a web-based submission page. The TMDB database is freely accessible from the URL of http://pcsb.ahau.edu.cn:8080/TCDB/index.jsp. The TMDB is designed to address the broad needs of tea biochemists, natural products chemists, nutritionists, and members of tea related research community.

Conclusion: The TMDB database provides a solid platform for collection, standardization, and searching of compounds information found in tea. As such this database will be a comprehensive repository for tea biochemistry and tea health research community.

Figure 1

Published items and citations for Tea chemistry during the latest 20 years.

Figure 2

TMDB: screenshot of drop-down box browse (left), name, other, and 1D NMR search.

Figure 3

Retrieve a compound in three search methods (name, other, and 1D NMR data), search results, and metabolites detailed information.

Figure 4

TMDB: screenshot of the webpage from which new data can be added by an authorized compiler.

Figure 5

Ten famous Chinese teas belong to the four categories of tea according to the increment of fermentation, up five: Xi-Hu Longjin, Lu-An Guapian, Huang-Shang Maofeng, Tai-Ping Houkui, Biluochun (all green tea, non-fermented); down five: Tianguanying (Oolong tea, semifermented), An-Xi white tea (partially fermented), Qi-Men also Keemun black tea (fully fermented), Pu-erh Tea (dark tea, post fermented), Jing-Wei Fu Brick tea (dark tea, post fermented).

Figure 6

Distribution of number of compounds per exact mass.