Two new brominated C₁₅-acetogenins from the red alga Laurencia japonensis

Abstract

We report on the chemical characteristics of the red alga Laurencia japonensis, collected off the coast of Yoshio, Katsuura, Boso Peninsula, Japan. We isolated two new brominated C 15 -acetogenins in this species, which we name katsuurenyne A (1) and katsuurenyne B (2), along with two already known halogenated terpenes [2,10-dibromo-3-chloro--chamigrene (7) and aplysiadiol (8)]. We extensively analysed spectral data (from IR, ESI-MS, 1D-NMR and 2D-NMR) to confirm the structure of these compounds.

Marine natural products

“…C 15 acetogenins are common metabolites of red algae, with reports of two new compounds each from Laurencia japonensis 902 , and 903 and L. nangii 904 , and 905 , respectively. 403,404 Teanol 906 is a dibromo-sesquiterpenoid that exhibits weak brine shrimp lethality, 405 while six new structurally diverse halo-sesquiterpenoids 907–912 were reported from L. composita . 406 Eight new halo-diterpenoids 913–920 were isolated from a Sphaerococcus species.…”

Review POTENT PHARMACEUTICAL PRODUCTS FROM AQUATIC PLANTS – REVIEW

“…Diterpenoids have been recorded in lesser numbers but not terpenoids. C15 acetogenins are also in larger number mostly halogenated [93]. Sesquiterpenoids are significant for human health.…”

New acetogenin katsuurallene from Laurencia saitoi collected from Katsuura, Japan

“…L. japonensis contained two new brominated acetogenins katsuurenyne A ( 7 ) (Fig. 1 ) and katsuurenyne B ( 8 ) along with known 2,10-dibromo-3-chloro-α-chamigrene ( 9 ) and aplysiadiol ( 10 ) [ 14 ]. Furthermore, in the coast of Yoshio, L. okamurae unusually grow sympatrically in morphological variation, a clumpy type and a non-clumpy type.…”