ABSTRACT
Objective: To investigate the chemical constituents from the whole plants of Carpesium macrocephalum. Methods: Its constituents were isolated and purified by means of silica gel, ODS, and Sephadex LH-20 column chromatography. Their structures were elucidated on the basis of chemical evidences, spectroscopic methods, and X-ray data. Results: Five thymol monoterpenoids were isolated from the acetone extract in the whole plants of C. macrocephalum and identified as (Z)-10-isobutyryloxy-9-chloro-8,9-dihydrothymol (1), 9-isobutyryloxy-7,8-epoxythymol isobutyrate (2), 8-hydroxy-9-isobutyryloxy-10(2)-methylbutyrylthymol (3),8,10-dihydroxy-9-isobutyryloxythymol (4), and 10-isobutyryloxy-8,9-dihydrothymol (5), respectively. Conclusion: Compound 1 is a new chlorinated thymol monoterpenoid named carpemacrom. Compounds 2-5 are isolated from the plants of Carpesium L. for the first time.