Algal-Derived Halogenated Sesquiterpenes from Laurencia dendroidea as Lead Compounds in Schistosomiasis Environmental Control.

Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (-)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.

Algal-derived halogenated Sesquiterpenes from Laurencia dendroidea as lead compounds in Schistosomiasis environmental control

Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (−)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.

Barcode e bioprospecção de metabólitos das algas marinhas Laurencia aldingensis, L. dendroidea e Laurenciella sp. (Ceramiales, Rhodophyta) / Barcode and bioprospecting of metabolites from the marine algae Laurencia aldingensis, L. dendroidea e Laurenciella sp. (Ceramiales, Rhodophyta)

A natureza e diversidade das estruturas químicas com atividade farmacológica que se tem encontrado nos organismos marinhos justificam a busca por novos compostos que são de interesse nas mais diversas áreas de aplicação. As espécies de macroalgas vermelhas, em especial Laurencia spp., merecem destaque pela enorme variedade de terpenos e acetogeninas que produzem, sendo consideradas de grande potencial na produção de novos fármacos. O estudo de seus constituintes pode fornecer importantes subsídios para a quimiotaxonomia, ecologia química, caracterização das espécies e avaliação do potencial biotecnológico. Baseado nisso, Laurencia aldingensis, L. dendroidea e Laurenciella sp. foram selecionadas para o presente estudo para isolamento, caracterização e teste de atividades biológicas dos seus compostos. A técnica do DNA barcoding foi utilizada como ferramenta de diagnóstico para garantir a similaridade entre as amostras de cada espécie, que foram coletadas em época e locais diferentes. Do extrato orgânico de Laurencia aldingensis, nove substâncias foram isoladas, sendo quatro esfingosinas (1-4), três terpenos (5-7) e duas novas substâncias halogenadas (8 e 9). Do extrato orgânico de Laurencia dendroidea formam isolados dois terpenos halogenados conhecidos (10, 11) e, do extrato de Laurenciella sp. três novas substâncias halogenadas alifáticas insaturadas (12-14), assim como um ácido graxo (15) e um esterol (16) conhecidos. Dentre elas, a 8 apresentou atividade citotóxica, mas não se mostrou seletivo, e as substâncias 4 e 11 apresentaram atividade esquistossomicida, bastante promissora. No entanto, nenhum deles apresentou atividade antioxidante. Diante desta investigação, podemos dizer que as informações geradas com os estudos de Laurencia aldingensis, L. dendroidea e Laurenciella sp. expandiram significantemente o conhecimento no que tange a diversidade química no gênero e o potencial biológico-farmacêutico dos mesmos

The nature and diversity of chemical structures with pharmacological activity that have been found in marine organisms justifies the search for new compounds that may have applications in various areas of interest. Species of red seaweeds, especially Laurencia spp., are special because of the unprecedented variety of terpenes and acetogenins they produce that are considered potentially useful for the production of new drugs. Study of their constituents can also provide important insights relating to their chemotaxonomy, chemical ecology, characterization of species and biotechnological potential. On this basis Laurencia aldingensis, L. dendroidea and Laurenciella sp., were selected for study and isolation, characterization, and biological activity assessment of isolatable quantities of their compounds. The technique of DNA barcoding was used as a diagnostic tool to ensure similarity between samples of each species collected at different times and places. From the organic extract of Laurencia aldingensis nine compounds were isolated; four sphingosines (1-4), three terpenes (5-7) and other two new halogenated compound (8, 9). From the organic extract of Laurencia dendroidea two known halogenated terpenes (10, 11) were isolated while from a similar extract of Laurenciella sp., three new halogenated aliphatic compounds (12-14) were isolated together with known fatty acid (15) and sterol (16). Among all isolates, 8 demonstrated unspecific cytotoxic activity and compounds 4 and 11 showed promising schistosomicidal activity. In applied antioxidant assays none of the isolates we noted to have activity. From the overall investigation it is also clear that the information gleaned from the studies of Laurencia aldingensis, L. dendroidea and Laurenciella sp., significantly expanded our knowledge base concerning chemical diversity in the genus Laurencia and their biological-pharmaceutical potential