Stereochemistry of a Second Riolozane and Other Diterpenoids from Jatropha dioica

  • J Nat Prod. 2017 Aug 25;80(8):2252-2262. doi: 10.1021/acs.jnatprod.7b00193.
Elda M Melchor-Martínez  1  2 ,  David A Silva-Mares  1 ,  Ernesto Torres-López  1 ,  Noemí Waksman-Minsky  1 ,  Guido F Pauli  3 ,  Shao-Nong Chen  3 ,  Matthias Niemitz  4 ,  Mariano Sánchez-Castellanos  2 ,  Alfredo Toscano  2 ,  Gabriel Cuevas  2 ,  Verónica M Rivas-Galindo  1
Affiliations
  • 1. Facultad de Medicina, Universidad Autónoma de Nuevo León , Avenida Madero y Aguirre Pequeño, Col. Mitras Centro s/n, Monterrey, N.L., C.P. 64460, México.
  • 2. Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, C. P. 04510, México.
  • 3. Center for Natural Product Technologies (CENAPT), Department of Medicinal Chemistry and Pharmacognosy, and Institute for Tuberculosis Research; College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
  • 4. NMR Solutions Ltd. , Puijonkatu 24B5, 70110 Kuopio, Finland.
PMID: 28771358 DOI: 10.1021/acs.jnatprod.7b00193
Abstract

The dichloromethane extract of the roots of Jatropha dioica afforded riolozatrione (1) and a C-6 epimer of riolozatrione, 6-epi-riolozatrione (2), as a new structure and only the second reported riolozane diterpenoid. The two known Diterpenoids jatrophatrione (3) and citlalitrione (4) were also isolated and characterized. Both epimers 1 and 2 are genuine plant constituents, with 2 likely being the biosynthesis precursor of 1 due to the tendency for the quantitative transformation of 2 into 1 under base catalysis. The structural characterization and distinction of the stereoisomers utilized 1H iterative full-spin analysis, yielding complete J-correlation maps that were represented as quantum interaction and linkage tables. The absolute configuration of compounds 1-4 was established by means of vibrational circular dichroism and via X-ray diffraction analysis for 1, 2, and 4. Additionally, the cytotoxic and antiherpetic in vitro activities of the isolates were evaluated.