Background: C. delpyi, C. decalvatus and C. caudatus are in the Euphorbiaceae family.
The aerial parts, such as twigs, leaves and barks of these plants are used as traditional medicine such
as anti-inflammatory, cytotoxicity, and antifungal properties.
Objectives: The aims of this work were 1) to study the chemical composition of C. delpyi, C. decalvatus,
and C. caudatus 2) to test the antibacterial, anti-HIV-1 RT, and cytotoxicity activities of crude
extracts and pure compounds from these plants.
Methods: Extraction, separation and purification of three plants were performed following chromatographic
method. The biological activities, including antibacterial, anti-HIV-1 RT and cytotoxicity
assay of three plants, were evaluated by the standard methods.
Results: Phytochemical investigation of C. delpyi highlighted a new clerodane diterpenoid; crotondelpyitin
A (1). The five known compounds were found, such as acetyl aleuritolic acid (2), 5-
hydroxy-7,4′-dimethoxyflavone (3), and pilloin (4) in C. decalvatus and 3α-benzoyloxy-D while Afriedo-
oleanan-27,16α-lactone (5), and bergenin (6) in C. caudatus. Compound 3 showed the most
effective antibacterial activities with MIC in range <0.16 -1.25 mg/mL, and MBC in range 0.6 - >5.0
mg/mL. The six compounds were inactive with anti-HIV-1 RT. In addition, compound 4 was active
for cytotoxic activities on FaDu and KKU-M213 at <4 μg/mL.
Conclusion: The present study reveals that the Croton species are sources of diterpenoid-type compounds
and a significant guide for further research of chemical constituents from these plants as potential