Novel 3-Dehydroteasterone Derivatives with 23,24-Dinorcholanic Side Chain and Benzoate Groups at C-22: Synthesis and Activity Evaluation by Rice Lamina Inclination Test and Bean Second-Internode Bioassay Valdés, Ernesto Díaz, Katy Núñez, María Olea, Andrés F. Quílez Del Moral, José Francisco Carvajal, Rodrigo Cuellar, Mauricio Espinoza Catalán, Luis 3-dehydroteasterone brassinosteroid analogs synthesis Herein, a new series of 3-DT analogs with benzoylated groups at C-23 are synthesized and characterized. The benzoylated groups carry the same substituents in the ortho- or para-positions. Thus, the effect of structure on activity, measured using the rice lamina inclination test (RLIT) and the bean second-internode assay (BSI), is evaluated. The RLIT results indicate that a benzoylate function at C-22 induces a strong increase in activity that depends on the position and nature of the substituent in the phenyl ring. For example, an analog with an -OAc group in the ortho-position is the most active derivative, and its activity is like that of brassinolide. A relative index is calculated using brassinolide as a positive control to compare the RLIT results with those reported previously. This analysis allows for the conclusion that benzoylated derivatives with a hydroxyl group at C-3 are much more active than the corresponding analogs with a carbonyl group in this position, and one extra alcohol group in the alkyl chain decreases RLIT activity. Finally, the results obtained with the BSI are clearly different to those obtained in the RLIT bioassay. Therefore, the application of any activity–structure relationship will always be dependent on the bioassay used to determine activity. 2025-09-23T10:57:59Z 2025-09-23T10:57:59Z 2025-09-06 journal article Valdés, E.; Díaz, K.; Núñez, M.; Olea, A.F.; Moral, J.F.Q.d.; Carvajal, R.; Cuellar, M.A.; Espinoza-Catalán, L. Novel 3-Dehydroteasterone Derivatives with 23,24-Dinorcholanic Side Chain and Benzoate Groups at C-22: Synthesis and Activity Evaluation by Rice Lamina Inclination Test and Bean Second-Internode Bioassay. Int. J. Mol. Sci. 2025, 26, 8710. https://doi.org/10.3390/ijms26178710 https://hdl.handle.net/10481/106558 10.3390/ijms26178710 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI