Structural Elucidation By NMR Of The Briarellin Carbon Skeleton.
DOI:
https://doi.org/10.54495/Rev.Cientifica.EdicionEspecial2008.183Keywords:
Gorgonian octocorals, Briareum, secondary metabolites, nuclear magnetic resonance, diterpenes, briarellins, asbestinins, 2D-NMR, sub-spin systemAbstract
Caribbean gorgonian corals of the genus Briareum (Cnidaria, Gorgonaceae), have proven to be an important source of bioactive secondary metabolites. The gorgonian produces mainly three type of diterpenes: asbestinins,
Caribbean gorgonians of the genus Briareum (Cnidaria, Gorgonaceae), are an important source of bioactive secondary metabolites.
They biosynthesize three basic types of diterpenes; asbestinines, briarellinas and briareinas. Briarellins A-R and briarellins D and K peroxides are the only metabolites that have the briarelline skeleton that have been isolated from a marine organism in the Caribbean region.
These highly functionalized diterpenes are part of the family of 2,11 cyclized Cembranoids, whose biosynthetic origin is proposed to derive from the cembrane carbon skeleton, via various oxidative cyclizations and methyl rearrangements.
In this work, the Nuclear Magnetic Resonance NMR-properties of the carbon skeleton of Briarellina and the comparison between the two types of existing briarellinas, and of these, with that of asbestinines, are widely discussed.
Through the concerted and exhaustive application of one- and two-dimensional NMR techniques, its four spin sub-systems and the connectivity between them to structure the carbon skeleton of the Briarellinas are shown.
By comparing the 'H-NMR and 13C-NMR spectra between asbestinines and the different types of briarellins, clear differences are documented that allow differentiating between these types of secondary metabolites and even the stereochemistry on certain quinal centers around the carbon skeleton. of these compounds.
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Rodríguez, A.D.; Cóbar, O.M. The briarellins, new eunicellin-based diterpenoids from a Caribbean gorgonian. Briareitm asbestinum. Tetrahedron 1995, 51, 6869-6880, https://doi.org/10.1016/0040-4020(95)00339-A DOI: https://doi.org/10.1016/0040-4020(95)00339-A
Rodríguez, A.D.; Cóbar, O.M. Studies on the minor constituents of the Caribbean gorgonian octocoral Briareum ashestinum Pallas. Isolation and structure determination of the euniccllin-based diterpenoids briarellins E-I. Chemical and Pharmaceutical Bulletin of Japan. 1995, 43, 1853-1858, https://doi.org/10.1248/cpb.43.1853 DOI: https://doi.org/10.1248/cpb.43.1853
Ospina. C.; Rodríguez, A.D.; Ortega-Barria, E.; Capson, T. Briarellins J-P and polyanthellin A: a new eunicellin-based diterpenes from the gorgonian coral Briareum polyanthes and their antimalarial activity. Journal of Natural Products. 2003, 66, 357-363, https://doi.org/10.1021/np0204500 DOI: https://doi.org/10.1021/np0204500
Ospina, C.; Rodríguez, A.D. Bioactive Compounds from the Gorgonian Briareum polyanthes. Journal of Natural Products. 2006, 69, 1721-1727, https://doi.org/10.1021/np060317y DOI: https://doi.org/10.1021/np060317y
Wang, G.H.; Shen, J.H.; Chiang, M.Y; Lee, T.S. Pachyclavulariaenones A-C, three novel diterpenoids from the soft coral Pachyclavularia violácea. Tetrahedron Letters. 2001, 42, 2333-2336, https://doi.org/10.1016/S0040-4039(01)00180-0 DOI: https://doi.org/10.1016/S0040-4039(01)00180-0
Wang, G.H.; Sheu, J.H.: Chiang, Y.D.; Chiang, M.Y, Pachyclavulariaenones D-G. new di terpenoids from the soft coral Pachyclavularia violácea. Journal of Natural Products. 2002, 65, 1475-1478. DOI: https://doi.org/10.1021/np020095d
Claridge, T.D . High Resolution NMR Techniques in Organic Chemistry. Pergamon, London, U.K. 1999.
Morales, J.J.; Lorenzo, D.; Rodríguez, A.D. Application of two-dimensional NMR spectroscopy in the structural determination of marine natural products. Isolation and total structural assignment of 4-deoxysbcstinin diterpenes from the Caribbean gorgonian Briareum asbestinum. Journal of Natural Products. 1991, 54, 1368-1382, https://doi.org/10.1021/np50077a021 DOI: https://doi.org/10.1021/np50077a021
Rodríguez, A.D. Two-dimensional NMR spectra of asbestinin diterpenes isolated from Briareum asbestinum (Pallas). Total stereochemical assignment by two-dimensional NMR techniques. Magnetic Resonance in Chemistry. 1992, 30, 977-986, https://doi.org/10.1002/mrc.1260301012 DOI: https://doi.org/10.1002/mrc.1260301012
Rodríguez, A.D.; Cóbar, O.M. ; Martínez, N. Isolation and structures of sixteen new asbestinin diterpenes from the Caribbean gorgonian Briareum ashestinum. Journal of Natural Products. 1994, 57, 1638-1655, https://doi.org/10.1021/np50114a005 DOI: https://doi.org/10.1021/np50114a005
Dewar, M.L; Zoebisch, E.G.; Healy, E.F.; Stewart, J. J. Development and use of quantum mechanical molecular models. 76. AMI: a new general purpose quantum mechanical molecular model. Journal of the American Chemical Society. 1985, 107, 3902-3909, https://doi.org/10.1021/ja00299a024 DOI: https://doi.org/10.1021/ja00299a024
G.B. Rocha, R.O. Freire, A. Simas and J.J.P. Stewart RM1: A reparameterization of AMI for H. C, N, O, P. S. F. Cl Br, and I, Journal of Computational Chemistry. 2006, 27, 1101-1111, https://doi.org/10.1002/jcc.20425 DOI: https://doi.org/10.1002/jcc.20425
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