The project started in 1991 and it has successively received financial support from 12 projects sponsored by the KIB State Key Laboratory of Phytochemistry and Plant Resources in West China, Yunnan Natural Science Foundation and National Natural Science Foundation of China with total fund amounting to RMB 700,000 yuan. Plant cyclopeptide is a very important plant metabolite and also a new thing in natural product chemistry. Studies on plant cyclopeptide have a history of nearly half a century ever since the discovering and identification of the structure of cyclolinopeptide A in 1959. Prior to the 1990’s, only 150 cyclopeptides had been identified, which were mainly cyclopeptide alkaloids. Some important structures and problems of function, however, have not been resolved in studies of plant cyclopeptides.
The project firstly began its studies on plant cyclopeptides at the beginning of the 1990’s and the research team has spent nearly 15 years carrying out continuing studies on plant since the founding of cyclopeptide A and cyclopeptide B of Pseudostellaria heterophylla. This project mainly includes studies on six aspects including establishment of chemistry system of plant cyclopeptides, finding of new plant cyclopeptide, studies on structure and biological significance of plant cyclopeptides, biosynthesis of plant cyclopeptides, basic researches on utilization of plant cyclopeptides and academic summary and new academic perspectives on plant cyclopeptides. Main research results can be described as follows:
An integral system for research of plant cyclopeptides including testing, extraction, isolation, purification, plain structure, absolute configuration, solution conformation and crystal structure studies was established. It should also be noted that another thin-layer testing method for plant cyclopeptides and a complete identification system for plant cyclopeptides that still works today, were established.
From 28 species of Caryophyllaceae and Annonaceae, 112 plant cyclopeptides had been found, among which 79 were new plant cyclopeptides.
Firstly claimed a new classified method of structures of plant cyclopeptides and put forward the new phytochemistry and taxology idea that the Caryophyllaceae plants can be classified by plant cyclopeptides.
Preliminary proved the enzyme cyclization reactions of cyclopeptide B of Pseudostellaria heterophylla and concluded that plant protein is the primary metabolites and other plant cyclopeptides are indirect genetic products.
A new quality-control method for medical material of Pseudostellaria heterophylla based on the contents of cyclopeptide A and B of Pseudostellaria heterophylla was described. It also noted that cyclopeptide in red ginseng and other overall cyclopeptide demonstrated anti-tumor activity.
The publication of a review about plant cyclopeptides on the world leading journal, Chemical Reviews (Impact factor 20.233 in 2004) symbolizes that the research achievements on plants cyclopeptide received wide recognition from the international academia.
The research team of this project has published 68 scientific articles (monographs), 40 SCI-index articles and 50 articles have been quoted for 355 times, 16 graduate students completed their dissertations based on research of this project and relative articles were once selected to the keynote report on internationals conferences.
The research team has already grown into a dominant research team of plant cyclopeptides in the whole world, receiving wide concerns, tracking and cooperation with counterparts, both home and abroad. The research achievements hold the internationally leading position with regard to testing method of plant cyclopeptides, finding of new compounds, classification of new structure, biosynthesis, academic summary and new academic ideas, generating tremendous influences to development of this specific research field.