Submitted to: Biochemical Systematics and Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 10, 1995
Publication Date: N/A
Interpretive Summary: The classification of the many different types of citrus plants has been a source of confusion for many years. Characterization of citrus plants by chemical "fingerprinting"--detailed analysis of unique chemicals accumulated by different plant species--is one way of sorting out this group of plants. This paper details the chemical analysis of two important tclasses of related chemical compounds produced by all citrus plants which are important to fruit and juice quality as well as to maintaining the plant's health. This chemical fingerprinting technique has been used to examine the papedas, a group of closely related plants, to the more economically important citrus plants. The chemical fingerprinting provides information that can be used by breeders in creating new rootstock cultivars for growing citrus. In addition, there is growing interest in the pharmaceutical and agricultural uses of citrus plant biochemicals that might be exploited commercially. This paper is the first significant chemical analysis of the papedas and may be used to determine other sources of specific citrus biochemicals from the papedas for future research.
Technical Abstract: The limonoids of the seeds and the flavonoids of the leaves of a number of papedas were examined. The seeds examined in this study showed that only the normal citrus limonoids and none of the other unique limonoids, such as ichangensin, were present. The flavonoid analysis showed that a number of papeda varieties including C. latipes, C. hystrix, and a papeda hybrid species C. junos had flavanone neoheperidosides, which is found in cultivars related to the pummelo. All papedas examined had rutin present which is found in cultivars related to the citron. Citrus ichangensis had the most complex flavone/flavonol pattern of all the papedas examined. This indicates that Citrus ichangensis may truly be a unique papeda species unlike that of the other papedas.