Limits...
Briacavatolides D-F, new briaranes from the Taiwanese octocoral Briareum excavatum.

Wang SK, Yeh TT, Duh CY - Mar Drugs (2012)

Bottom Line: In the continued search for novel bioactive substances from the Taiwanese octocoral Briareum excavatum collected at Orchid Island, three new briarane-type diterpenoids, briacavatolides D-F (1-3) were isolated from the acetone extract.The structures of these compounds were elucidated by extensive NMR spectroscopic analysis and physical data.The anti-HCMV (human cytomegalovirus) activity of 1-3 and their cytotoxicity against selected cancer cell lines were evaluated.

View Article: PubMed Central - PubMed

Affiliation: Asia-Pacific Ocean Research Center, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. skwang@cc.kmu.edu.tw

ABSTRACT
In the continued search for novel bioactive substances from the Taiwanese octocoral Briareum excavatum collected at Orchid Island, three new briarane-type diterpenoids, briacavatolides D-F (1-3) were isolated from the acetone extract. The structures of these compounds were elucidated by extensive NMR spectroscopic analysis and physical data. The anti-HCMV (human cytomegalovirus) activity of 1-3 and their cytotoxicity against selected cancer cell lines were evaluated.

Show MeSH

Related in: MedlinePlus

2D NMR correlations of compound 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3475276&req=5

marinedrugs-10-02103-f003: 2D NMR correlations of compound 1.

Mentions: Briacavatolide D (1) was obtained as a white powder. Its HRMS and NMR spectral data established a molecular formula of C24H32O11, implying the existence of eight double bond equivalents. The 1H and 13C NMR spectra (Table 1) of 1 indicated the presence of two acetoxyls (δH 1.97, 2.03; δC 21.2, 21.1, 171.8, 170.6), a γ-lactone (δH 6.22; δC 172.2), and a trisubstituted olefin (δH 5.71; δC 149.3, 124.0). A tetrasubstituted epoxide containing a methyl substituent was indicateded by the signals of two quaternary oxygenated carbons (δC 62.6, 71.1) and a methyl (δC 9.3; δH 1.67, 3H, s). A trisubstituted epoxide containing a methyl substituent was revealed from the signals of an oxymethine (δC 61.4; δH 3.05) and a quaternary oxygenated carbons (δC 63.5) and a methyl (δC 24.6; δH 1.33, 3H, s). From the above data, metabolite 1 was found to be a pentacyclic compound. The structure and the 1H and 13C chemical shifts of 1 were assigned by the assistance of 2D NMR studies, including 1H–1H COSY and HMBC experiments (Figure 3). By analysis of 1H–1H COSY correlations (Figure 3), it was possible to establish four partial structures of consecutive proton systems extending from H-2 to H-4; H3-16 to H-7 through H-6; H-6 to H-7; H-9 to H-10; and H-12 to H-14 through H-13. HMBC correlations (Figure 3) further led to the connectivities of the gross structure. According to the above observations, metabolite 1 seemed to be very similar to 16-hydroxystecholide C acetate [6], which was previously isolated from the soft coral Solenopodium excavatum. By means of 1D and 2D NMR data it was found that the acetoxy groups at the C-4 and C-9 positions in 16-hydroxystecholide C acetate were replaced by hydroxy groups 1. On the basis of the above finding, and by the NOE correlations of 1 (Figure 3), bricavatolide D (1) was found to be the 4-O-deacetyl-9-O-deacetyl derivative of 16-hydroxystecholide C acetate.


Briacavatolides D-F, new briaranes from the Taiwanese octocoral Briareum excavatum.

Wang SK, Yeh TT, Duh CY - Mar Drugs (2012)

2D NMR correlations of compound 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475276&req=5

marinedrugs-10-02103-f003: 2D NMR correlations of compound 1.
Mentions: Briacavatolide D (1) was obtained as a white powder. Its HRMS and NMR spectral data established a molecular formula of C24H32O11, implying the existence of eight double bond equivalents. The 1H and 13C NMR spectra (Table 1) of 1 indicated the presence of two acetoxyls (δH 1.97, 2.03; δC 21.2, 21.1, 171.8, 170.6), a γ-lactone (δH 6.22; δC 172.2), and a trisubstituted olefin (δH 5.71; δC 149.3, 124.0). A tetrasubstituted epoxide containing a methyl substituent was indicateded by the signals of two quaternary oxygenated carbons (δC 62.6, 71.1) and a methyl (δC 9.3; δH 1.67, 3H, s). A trisubstituted epoxide containing a methyl substituent was revealed from the signals of an oxymethine (δC 61.4; δH 3.05) and a quaternary oxygenated carbons (δC 63.5) and a methyl (δC 24.6; δH 1.33, 3H, s). From the above data, metabolite 1 was found to be a pentacyclic compound. The structure and the 1H and 13C chemical shifts of 1 were assigned by the assistance of 2D NMR studies, including 1H–1H COSY and HMBC experiments (Figure 3). By analysis of 1H–1H COSY correlations (Figure 3), it was possible to establish four partial structures of consecutive proton systems extending from H-2 to H-4; H3-16 to H-7 through H-6; H-6 to H-7; H-9 to H-10; and H-12 to H-14 through H-13. HMBC correlations (Figure 3) further led to the connectivities of the gross structure. According to the above observations, metabolite 1 seemed to be very similar to 16-hydroxystecholide C acetate [6], which was previously isolated from the soft coral Solenopodium excavatum. By means of 1D and 2D NMR data it was found that the acetoxy groups at the C-4 and C-9 positions in 16-hydroxystecholide C acetate were replaced by hydroxy groups 1. On the basis of the above finding, and by the NOE correlations of 1 (Figure 3), bricavatolide D (1) was found to be the 4-O-deacetyl-9-O-deacetyl derivative of 16-hydroxystecholide C acetate.

Bottom Line: In the continued search for novel bioactive substances from the Taiwanese octocoral Briareum excavatum collected at Orchid Island, three new briarane-type diterpenoids, briacavatolides D-F (1-3) were isolated from the acetone extract.The structures of these compounds were elucidated by extensive NMR spectroscopic analysis and physical data.The anti-HCMV (human cytomegalovirus) activity of 1-3 and their cytotoxicity against selected cancer cell lines were evaluated.

View Article: PubMed Central - PubMed

Affiliation: Asia-Pacific Ocean Research Center, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. skwang@cc.kmu.edu.tw

ABSTRACT
In the continued search for novel bioactive substances from the Taiwanese octocoral Briareum excavatum collected at Orchid Island, three new briarane-type diterpenoids, briacavatolides D-F (1-3) were isolated from the acetone extract. The structures of these compounds were elucidated by extensive NMR spectroscopic analysis and physical data. The anti-HCMV (human cytomegalovirus) activity of 1-3 and their cytotoxicity against selected cancer cell lines were evaluated.

Show MeSH
Related in: MedlinePlus