Sesquiterpenes and acetogenins from the marine red alga Laurencia okamurai

Phytochemical and Biological Properties of Sesquiterpene Constituents From the Marine Red Seaweed Laurencia: A Review

“…The authors suggested that both 125 and 126 are formed as artefacts from compound 129 [83]. The previously reported allolaurinterol acetate (131) [84] was isolated again in 2012 from L. okamurai [25], while, isolaurenisol, (132) previously reported from L.gracilis [85] was obtained in 2009 from L. saitoi [46]. 3 β -hydroxyaplysin (133) was isolated from L.okamurai (Nanji Is., China) [68] while, L. microcladia (Chios Is., North Aegean Sea) provided the aromatic sesquiterpenes (134-136) and the dimeric brominated sesquiterpene 137 [60].…”

“…In addition to marine organisms, cuparanes are found in liverworts and higher plants [66] (Figure 4). L. okamurai, collected from the coast of Rongcheng, China, yielded 10-bromo-3-chlorocupar-5-en-2-ol (83) [25]. It is notable that most of the cuparane sesquiterpenes isolated from seaweeds have an aromatic ring such as compounds 84-86, isolated from the Greek L. microcladia, collected at Chios Island in the North Aegean Sea.…”

“…The Chinese L. okamurai collected from the coast of Rongcheng, yielded laurene (90), originally isolated from L. glandulifera and L. nipponica [70], and 7-hydroxylaurene acetate (91). Compound 90 exhibited potent antibacterial activity and lethal toxicity to brine shrimp [25]. However, 7-hydroxylaurene (92) was reported in 1977 as novel compound from L. subopposita and L. okamurai [71].…”

“…In 2010, a L. composita sample collected from the same area contained (8β)-10-bromo-3-chloro-2,7-epoxychamigr-9-en-8-ol (24) [32]. Elatol (25), isolated for the first time from L. elata in 1974 [33], was obtained in high yield of ca. 10% (w/w) from the ethanolic extract of L. microcladia [34].…”

Nonhalogenated organic molecules from Laurencia algae

“…Based the high degrees (at least five) of unsaturation and the key role of bromonium ion in the assembly of chamigrane backbone (Wang et al 2013 (52), and rearranged laurane (53 and 54) members from ten Laurencia species. Nine (22,32,35,40,47,49,50,53, and 54) of these 33 sesquiterpenes were identified from Chinese or Japanese L. okamurai Kurosawa 1978, 1979;Li et al 2012b;Feutrill et al 1973;Mao and Guo 2005, and 40 was also reported as a new constituent from Greek L. microcladia simultaneously (Kladi et al 2005). The absolute configuration of 53 was established by an enantioselective total synthesis starting from (S)-campholenaldehyde (Srikrishna et al 2008), and one of the intermediates afforded a valuable reference to confirm the absolute configuration of 54 (Srikrishna et al 2008;Mao and Guo 2010).…”