Halogenated Sesquiterpenoids from the Red Alga Laurencia tristicha Collected in Taiwan

Abstract

Chemical investigation of the red alga Laurencia tristicha led to the discovery of eight new halogenated chamigrane-type sesquiterpenoids (1-8) and one new bromocuparane-type sesquiterpene (9), along with nine known related metabolites (10-18). Their structures were elucidated on the basis of extensive spectroscopic analyses, and the absolute configurations of 1-8 were proposed by comparison to the biosynthetically related known compound 12. Cytotoxicity, antibacterial, and anti-inflammatory activities of these isolates were also investigated. The results showed that compound 11 exhibited good antibacterial activity against Serratia marcescens compared to the positive control ampicillin at a dosage of 100 μg/disk. Compound 17 showed strong inhibition toward elastase release generation at 10 μM.

Marine natural products

“…365 A synthesis of (À)-bisezekayne A 754 (Aplysia oculifera 366 ) has led to a structural revision and the determination of absolute conguration. 367 Sesquiterpenoids continue to be commonly encountered in the red algae, with nine brominated chamigrene and cuparane sesquiterpenoids 755-763 being obtained from Laurencia tristicha, 368 the eudesmane 764 from L. obtusa, 369 three brominated eudesmanes (selinanes) 765-767 and a brominated cycloeudesmane 768 from L. pinnata. 370 Three meroterpenoids 769-771 with variable anti-oxidative activities were characterised from Hypnea musciformis.…”

Meroterpenoids from the Brown Alga Cystoseira usneoides as Potential Anti-Inflammatory and Lung Anticancer Agents

“…Other terpenes from Dictyota plectens showed anti-inflammatory effects by inhibiting the LPS-induced NO production in mouse peritoneal macrophages [50]. Recently, several halogenated sesquiterpenoids from the red alga Laurencia tristicha and meroterpenoids from the brown alga Homoeostrichus formosana, also showed an interesting anti-inflammatory ability by inhibiting the N-formylmethionyl-leucyl-phenylalanine cytochalasin B (fMLP/CB)-induced superoxide anion (O 2 −• ) generation and elastase release in human neutrophils [51,52]. The results obtained in our study of the effects of the AMTs 1-8 on LPS-stimulated THP-1 macrophages are in line with the anti-inflammatory activities described above.…”

Bioactive compounds against neglected diseases isolated from macroalgae: a review

“…These compounds showed wide spectra of activity against Gram-positive bacteria, including vancomycin-susceptible strains such as methicillin-resistant Staphylococcus aureus, penicillinresistant Streptococcus pneumoniae, and Enterococcus strains, regardless their phenotype of resistance to vancomycin (Vairappan et al 2004). Chen et al (2016) isolated eight new halogenated chamigrane sesquiterpenes, a new bromocuparane, and nine known related metabolites from Laurencia tristicha collected in Taiwan and tested against Enterobacter aerogenes, Yersinia enterocolitica, and Serratia marcescens. The chamigrane 10 had half of the activity of ampicillin towards Y. enterocolitica, while the known secondary metabolites 11 and 12 were able to inhibit the growth of the bacteria S. marcescens similarly to ampicillin (Chen et al 2016).…”

“…Chen et al (2016) isolated eight new halogenated chamigrane sesquiterpenes, a new bromocuparane, and nine known related metabolites from Laurencia tristicha collected in Taiwan and tested against Enterobacter aerogenes, Yersinia enterocolitica, and Serratia marcescens. The chamigrane 10 had half of the activity of ampicillin towards Y. enterocolitica, while the known secondary metabolites 11 and 12 were able to inhibit the growth of the bacteria S. marcescens similarly to ampicillin (Chen et al 2016). Davyt et al (2001) isolated eight sesquiterpenes βchamigrane-type from the dichloromethane extract of Laurencia scoparia and demonstrated their activity against the parasitant stage of the helminth model Nippostrongylus brasiliensis.…”