Skip to main content
ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #433830
Research Project: Improving Product Quality and Innovation Through Phytochemical Optimization and Discovery of Natural Product-based Solutions

Location: Natural Products Utilization Research

Title: Chemical Composition of Eriodictyon californicum (California Yerba Santa) Cultivated in Ontario, Oregon, USA

Author
item SHOCK, CLINTON - Oregon State University
item POUDEL, AMBIKA - Aromatic Plant Research Center
item SATYAL, PRABODH - Aromatic Plant Research Center
item ZHAO, JIANPING - University Of Mississippi
item LEE, JOSEPH - University Of Mississippi
item Wang, Mei
item SETZER, WILLIAM - University Of Alabama In Huntsville

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2026
Publication Date: 4/21/2026
Citation: Shock, C., Poudel, A., Satyal, P., Zhao, J., Lee, J., Wang, M., Setzer, W.N. 2026. Chemical Composition of Eriodictyon californicum (California Yerba Santa) Cultivated in Ontario, Oregon, USA. Molecules. 31(8):1356. https://doi.org/10.3390/molecules31081356.
DOI: https://doi.org/10.3390/molecules31081356

Interpretive Summary: Eriodictyon californicum (California yerba santa), is a chaparral shrub native to California and southwestern Oregon. For generations, several California Native American tribes used it to treat colds, respiratory illnesses, asthma, rheumatism, and skin conditions. This long-standing medicinal use has sparked modern scientific interest in the species. Phytochemical research has revealed that E. californicum contains a diverse suite of biologically active compounds. Despite this rich chemical profile, one major aspect of the plant’s chemistry has remained unexplored: its essential oil composition. The present study addresses that gap by analyzing both the essential oils and the polyphenolic constituents of ten different accessions of E. californicum. By pairing essential-oil profiling with polyphenol analysis, the work provides a more complete picture of the plant’s chemical diversity and lays the groundwork for understanding how these compounds may contribute to its traditional medicinal properties.

Technical Abstract: Leaves from California yerba santa (Eriodictyon californicum) have been used historically by indigenous peoples for medicinal purposes. Recent research has ascribed potential pharmaceutical effects to leaf polyphenols, without consideration of other constituents. Based on prior analyses of polyphenols in leaves sampled in nature, five accessions thought to be rich in sterubin and five accessions known to be rich in eriolic acid C were grown from seed at Ontario, Oregon and samples of their leaves were harvested and evaluated for their essential oil and polyphenol contents. Major essential oil components in E. californicum were 1,8-cineole (0.6-35.5%), (Z)-ß-ocimene (6.8-15.7%), terpinen-4-ol (8.3-16.1%), a-pinene (2.6-13.6%), ß-phellandrene (1.9-11.7%), '-terpinene (4.6-7.9%), ethyl (E)-cinnamate (0.2-8.9%), a-terpineol (1.5-5.2%), p-cymene (2.0-5.3%), and ß-pinene (0.6-6.8%). Fifteen polyphenols were identified with prominence of eriolic acid C, rosmarinic acid, sterubin, homoeriodictyol, 6-methoxynaringenin, hesperetin, and eriodictyol. Essential oils may contribute to the medicinal properties of the leaves of California yerba santa. Results from the ten samples were evaluated for both polyphenols and essential oils; the variations in several essential oils may be correlated to variations in some of the polyphenols.