Four New Hydroazulenoid Diterpenes from the Tropical Marine Brown AlgaDictyota volubilis

Abstract

The marine brown alga, DICTYOTA VOLUBILIS, was found to contain four unusually substituted hydroazulenoid diterpenes ( 1 - 4) as well as the known compounds dictyol G acetate ( 5) and dilophol. The structures of all isolates were secured by detailed analysis of their spectroscopic data; IR, MS, and NMR.

The Biodiversity of the Genus Dictyota: Phytochemical and Pharmacological Natural Products Prospectives

“…Dictyol G acetate (11), 6-[(3αS,4R,5S,7R,8αR)-4-(acetyloxy)-7-hydroxy-3-methyl-8-methylidene-1,3α,4,5,6,7,8,8α-octahydroazulen-5-yl]-2-methylhept-2-ene-4,5-diyl diacetate (215), 6-[(3αS,4R,5S,7R,8αR)-4,7-dihydroxy-3-methyl-8-methylidene-1,3α,4,5,6,7, 8,8α-octahydroazulen-5-yl]-2-methylhept-2-ene-4,5-diyl diacetate (216), (4E)-2-[(3αS,4R,5S, 7R,8αR)-4,7-dihydroxy-3-methyl-8-methylidene-1,3α,4,5,6,7,8,8α-octahydroazulen-5-yl]-6hydroxy-6-methylhept-4-en-3-yl acetate (217), 6-methyl-2-[(3αR,4R,5S,7R,8αR)-3,4,7trihydroxy-3-methyl-8-methylidene-3,3α,4,5,6,7,8,8α-octahydroazulen-5-yl]hept-5-en-3-yl acetate (218) and dilophol (219) are highly oxidized hydroazulenoid diterpenes from D. dichotoma var. volubilis collected from Geoffrey Bay (Australia) (Figure 8) [87].…”

Diterpenes from the Marine Algae of the Genus Dictyota

“…Compound 7 also displayed a significant inhibitory effect on rat liver microsomal diacylglycerol acyltransferase with an IC 50 value of 46.0 μM [ 24 ]. Dictyol G acetate ( 8 ) was obtained from D. volubilis , collected from the reef flat of Geoffrey Bay, Magnetic Island, Australia [ 25 ], and also from D. binghamiae , collected from Barkley Sound, British Columbia [ 26 ]. Dictyol H ( 9 ) was reported from D. divaricata , collected from the Great Barrier Reef region of Northern Australia [ 27 ], and also from D. dentata from the south west coast of Barbados [ 28 ].…”

“…Compounds 30 – 33 were isolated from D. volubilis which was collected from Magnetic Island, Queensland, Australia [ 25 ]. Compounds 34 – 41 , which are highly oxidized prenylated-guaiane diterpenes, were reported from D. volubilis [ 31 ].…”

Isolation of Diacyl Glycerol Acyl Transferase (DGAT) Inhibitors from Pachydictyon coriaceum

“…Brown algae are known to have few diterpenoids. However, the brown alga, Dictyota volubilis, has been found to contain four unusually substituted hydroazulenoid diterpenes as well as the known compounds, dictyol G acetate and dilophol (König et al, 1993). Two new hydroazulenoid (prenyl guaiane) diterpenes, dictyone acetate and 3, 4-epoxy 13-hydroxy pachydictyol A, have been isolated from the petroleum ether fraction of the alcohol extract of the brown alga, Dictyota dichotoma (Siamopoulou et al, 2004).…”