Trijugins A and B, tetranortriterpenoids with a novel rearranged carbon skeleton from Heyneatrijuga (Meliaceae)

1987 ◽  
Vol 65 (1) ◽  
pp. 35-37 ◽  
Author(s):  
Kozhiparambil K. Purushothaman ◽  
Mathuram Venkatanarasimhan ◽  
Ayyappath Sarada ◽  
Joseph D. Connolly ◽  
David S. Rycroft
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Long Range ◽  
Nuclear Overhauser Effect ◽  
Carbon Skeleton ◽  
Overhauser Effect ◽  
Spectroscopic Examination ◽  
Effect Difference ◽  
Nuclear Overhauser ◽  
Derivatives Of

Two new tetranortriterpenoids, trijugins A (1) and B (3), isolated from the leaves of Heyneatrijuga (Meliaceae), have been shown to be derivatives of methyl angolensate but with a novel carbon skeleton having a contracted ring C. The structures were assigned on the basis of detailed 1H and 13C nuclear magnetic resonance spectroscopic examination including 2D long-range δC/δH correlation and homonuclear 1H nuclear Overhauser effect difference experiments.

The isolation, structure, and stereochemistry of traversiadiene. The precursor hydrocarbon of traversianal biosynthesis

1989 ◽  
Vol 67 (8) ◽  
pp. 1302-1304 ◽  
Author(s):  
Albert Stoessl ◽  
G. L. Rock ◽  
J. B. Stothers
Keyword(s):  
Magnetic Resonance ◽  
Biosynthetic Pathway ◽  
Nuclear Overhauser Effect ◽  
Difference Spectra ◽  
Heteronuclear Correlation ◽  
Magnetic Resonance Studies ◽  
Overhauser Effect ◽  
Effect Difference ◽  
Nuclear Overhauser ◽  
Magnetic Resonance Spectra

A tricyclic diene, traversiadiene, isolated from cultures of Cercosporatraversiana has been shown to have the structure and stereochemistry of the previously postulated hydrocarbon intermediate on the biosynthetic pathway to traversianal (1). Detailed:1H and 13C magnetic resonance studies, including homo- and heteronuclear correlation spectra, led to the gross structure, and the stereochemistry was established through a series of nuclear Overhauser effect difference spectra. Keywords: diterpene, traversiadiene, 1H and 13C magnetic resonance spectra.

The structure, stereochemistry, and biosynthetic origin of a diterpenoid fungal metabolite, traversianal, established by 1H, 2H, and 13C magnetic resonance

1988 ◽  
Vol 66 (5) ◽  
pp. 1084-1090 ◽  
Author(s):  
Albert Stoessl ◽  
G. L. Rock ◽  
J. B. Stothers ◽  
R. C. Zimmer
Keyword(s):  
Magnetic Resonance ◽  
Nuclear Overhauser Effect ◽  
Acetate Incorporation ◽  
Fungal Metabolite ◽  
Difference Spectra ◽  
Methyl Group ◽  
Heteronuclear Correlation ◽  
Overhauser Effect ◽  
Effect Difference ◽  
Nuclear Overhauser

The structure of traversianal, a tricyclic diterpenoid fungal metabolite of Cercospora traversiana, has been elucidated through detailed 1H and 13C magnetic resonance studies, including homo- and heteronuclear correlation spectra of the natural product and examination of 13C-labelled material obtained by [1,2-13C2]acetate incorporation experiments. Its stereochemistry was established from a series of nuclear Overhauser effect difference spectra. The tricyclic carbon skeleton of traversianal is that of the fusicoccin/cotylenin and ophiobolane terpenes although the oxygenation pattern closely resembles the latter. Incorporation experiments with [2,2,2-2H3, 1-13C1]acetate revealed that traversianal arises by a sequence that differs substantially from that established for the fusicoccanes but rather resembles that previously shown for the ophiobolanes, in the retention of hydride at C-2, -10, and -14. However, the opposite configuration of the methyl group at C-3 suggests that the route to traversianal involves a terminal trans-geranylgeranyl unit instead of the cis unit implicated in ophiobolin generation.

Sign in / Sign up

Export Citation Format

Share Document