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Taxonomy—the classification of species—is an important branch of biology that allows us to systematically understand and study biodiversity. Conventional taxonomy relies heavily on morphological and anatomical structures for classification, but recent discoveries of potentially cryptic species and morphological plasticity in many species underscore the importance of having an alternative or complementary method for species classification. In this paper, we discuss the emerging method of classification using biochemical signals, i.e., chemotaxonomy. We also present a case study on the feasibility of biomarker-based chemotaxonomy on the marine red alga Laurencia snackeyi using halogenated snyderane-type sesquiterpenes, which were proposed in earlier studies. [ABSTRACT FROM AUTHOR]

This study examines the importance of both macroalgal heterogeneity and specific macroalgal species or morphotypes to nursery provision for juvenile sparids (Diplodus capensis and Sarpa salpa) in a shallow (< 2 m), sheltered rocky cove in warm-temperate Algoa Bay, South Africa. The rocky cove is comprised of a mosaic of two main benthic habitats; canopy-forming Plocamium corallorhiza beds on rocky outcrops and flat reef dominated by low growing red algae morphotypes. We assessed macroalgal communities and the trophic ecology (stomach contents and isotopes), abundance and size structure of D. capensis and S. salpa in the two different benthic habitats and the resources/food associated with the dominant macroalgae species/morphotypes. We found high densities of S. salpa and D. capensis, in both high profile reef (rocky outcrops) and low profile (flat) reef. Within this habitat mosaic resources (epiphytes and macroinvertebrates) were more abundant in the non-canopy forming low growing macroalgae (Laurencia spp. and coralline turf algae) and these algae were also assimilated in the diets of both sparids. The high abundance of both juvenile S. salpa and D. capensis in high profile and low profile reef, suggests that within this mosaic of habitats these species may be using canopy-forming algae in the high profile reef for shelter and non-canopy forming algae in both the high and low profile reef for food. This shows that macroalgal habitats comprising several morphotypes have the potential to support higher juvenile diversity and abundance through both food provision and shelter. [ABSTRACT FROM AUTHOR]

The findings of this study expanded the geographic distribution of the genus Corynecladia J.Agardh, thought to be endemic to Australia. It is recorded for the first time as present in Europe, with two newly proposed species: C. millarii sp. nov. and C. mediterranea sp. nov. New collections belonging to the Laurencia complex were sampled from the Sicilian coasts of Italy. Examination of this material was carried out using both morphological comparisons and phylogenetic analyses of chloroplast (rbcL) and mitochondrial (COI-5P) nucleotide sequences. The resulting phylogenetic trees divided the Mediterranean specimens into two supported, separate branches, within the genus Corynecladia. Morphological analysis supported placement of these species within Corynecladia and as distinct from other congeners. Specifically, the two new species were conspicuous in the absence of a secondary cortex which is typical of other Corynecladia taxa. Included in this study is a detailed dichotomous key to the Laurencia complex taxa of the Mediterranean. [ABSTRACT FROM AUTHOR]

The identification of macroalgal species within the Laurencia complex is challenging, due to the presence of inconspicuous morphological characters, extensive variation in these traits and a diverse biogeography. Moreover, for a number of these species, no DNA sequence data are available in online databases. For this study, five algal specimens, tentatively assigned to Laurencia, were collected from Malta in the central Mediterranean Sea and studied using an integrative systematics approach. An analysis of the data resulted in the description of a new species, Laurencia mediterranea using combined morphological and molecular criteria, including COI-5P and rbcL. Morphologically L. mediterranea sp. nov. was distinct from other Laurencia spp. in the type of holdfast, the colour and shape of the thallus, the presence of secondary pit connections, lenticular thickenings and 'corps en cerise'. Moreover, a new genetic species cluster indicated a separate taxon at the species level. Our study demonstrates that genetic sequences having clear links to sample metadata and digital herbaria are indispensable for macroalgal biodiversity research. This approach could offer a solution for algal taxonomy in cases where biogeography is important and limited sequence data exist in online DNA libraries. [ABSTRACT FROM AUTHOR]

Parasitic red algae are an interesting system for investigating the genetic changes that occur in parasites. These parasites have evolved independently multiple times within the red algae. The functional loss of plastid genomes can be investigated in these multiple independent examples, and fine‐scale patterns may be discerned. The only plastid genomes from red algal parasites known so far are highly reduced and missing almost all photosynthetic genes. Our study assembled and annotated plastid genomes from the parasites Janczewskia tasmanica and its two Laurencia host species (Laurencia elata and one unidentified Laurencia sp. A25) from Australia and Janczewskia verruciformis, its host species (Laurencia catarinensis), and the closest known free‐living relative (Laurencia obtusa) from the Canary Islands (Spain). For the first time we show parasitic red algal plastid genomes that are similar in size and gene content to free‐living host species without any gene loss or genome reduction. The only exception was two pseudogenes (moeB and ycf46) found in the plastid genome of both isolates of J. tasmanica, indicating potential for future loss of these genes. Further comparative analyses with the three highly reduced plastid genomes showed possible gene loss patterns, in which photosynthetic gene categories were lost followed by other gene categories. Phylogenetic analyses did not confirm monophyly of Janczewskia, and the genus was subsumed into Laurencia. Further investigations will determine if any convergent small‐scale patterns of gene loss exist in parasitic red algae and how these are applicable to other parasitic systems. [ABSTRACT FROM AUTHOR]

The genus Laurencia, a category of marine red algae, is well recognized for producing a large variety of natural products (NPs) that are both chemically intriguing and structurally distinct. The aim of this research was to identify NPs with potential anti-SARS-CoV-2 activity. The crystals of the proteins RdRp and nsp15 were obtained from the RCSB protein database. About 300 NPs were discovered using the PubChem, ChemSpider, and CMNPD databases. The program Autodock Vina was used to conduct the molecular docking procedure once the proteins and ligands were prepared. Before running MD simulations using the CABS-flex 2.0 website, binding affinity assessments and interactions between amino acids were carefully reviewed. Only nine NPs were shortlisted to be examined further. Bromophycolide R, S, and bromophycoic acid C show the tendency to inhibit RdRp by β-hairpin motif binding at the N-terminal known as Active site 2 (AS2), whereas the other four NPs, bromophycolide E, H, P, and thyrsenol A, may effectively inhibit RdRp through interactions via C-terminal, also known as the Active site 1 (AS1). For the enzyme nsp15, bromophycoic B, C, and floridoside showed plausible interactions. In conclusion, out of nine, seven candidates shortlisted for RdRp exhibited strong interactions with the key residues in the AS1 and AS2 regions. Bromophycoic acid C may work as a dual inhibitor due to its favorable interactions with the nsp15 protein and RdRp's N-terminal, with affinities of −8.5 and −8.2 kcal/mol, respectively. [ABSTRACT FROM AUTHOR]

Determining the structures of new natural products from marine species not only enriches our understanding of the diverse chemistry of these species, but can also lead to the discovery of compounds with novel and/or important biological activities. Herein, we describe the isolation of isomaneonene C (1), a new halogenated C15 acetogenin, and three known compounds, α-snyderol (2), cis-maneonene D (3), and isomaneonene B (4), from the organic extract obtained from the red alga Laurencia cf. mariannensis collected from Iheya Island, Okinawa, Japan. The structures of these secondary metabolites were elucidated spectroscopically. All compounds were inactive at 30 μg/disc against methicillin-resistant Staphylococcus aureus (MRSA) in combination treatment with a β-lactam drug, meropenem. [ABSTRACT FROM AUTHOR]

Two new halogenated metabolites, laurenhalogens A (1) and B (2), along with four known ones (3–6), were isolated from the red alga Laurencia sp. The structures of 1 and 2 were determined by the means of UV, IR, MS, NMR and X-ray diffraction analysis. In addition, the antibacterial activities of 1–6 were also evaluated. [ABSTRACT FROM AUTHOR]

In India, Kappaphycus alvarezii is the only alga being cultivated commercially for kappa carrageenan production and also being utilized for the socioeconomic upliftment of coastal rural population in India in the form of their cultivation and marketing. The production has been substantially increased from 21 dry tonnes to 1490 dry tonnes with increasing market purchase value from US$ 0.061 to 0.469 kg dry wt−1 during 2001–2013. In India, annual import for carrageenan is 1800–2000 M tons year−1 and its demand is reported to be increased by 5–6% every year (Mantri et al. 2017). To date, Aquagri Pvt Ltd is the only company in India producing kappa carrageenan from cultivated Kappaphycus alvarezii (Mantri et al. 2017). However, few other marine phycocolloid processing factories are producing kappa carrageenan from Hypnea musciformis and Hypnea valentiae at cottage level. The total annual production of carrageenan in India ranges between 100 and 132 tons. There is tremendous demand for other carrageenan such as iota and lambda carrageenan in food, beverage, and consumer product manufacturing industries. In order to ascertain suitability of unexplored other indigenous carrageenophytes for commercial cultivation in India, several red algal species such as Agardhiella subulata, Ahnfeltiopsis pygmaea, Laurencia caraibica, and Solieria robusta were collected from wild habitats in Kanyakumari (N 08°08′10.36″; E 077°34′28.06″) Tamil Nadu, India, and were evaluated for their mariculture potential and the presence of carrageenan. Preliminary cultivation experiments were carried out by raft culture method (1 × 1 m) for 45 days at two harvest cycles at Thonithurai (N 09°16′53.45″; E 079°11′19.22″), Tamil Nadu, South eastern coast of India. Except Ahnfeltiopsis pygmaea, all other seaweeds investigated showed daily growth rate (DGR) in the range of 1.59 to 3.822% and confirmed its mariculture potential. Phycocolloid was extracted with yield 4.5 to 29.37% from dry seaweed residues obtained after extraction of lipids using both water and aqueous alkali [5% Ca (OH)2 solution]. Water was found the better solvent in terms of higher yield of the Phycocolloid (29.37%) from Solieria robusta. FT-IR of the extracted phycocolloid indicated presence of characteristic bands for carrageenan in all the samples. However, from the band positions, the presence of iota carrageenan was ascertained in the Agardhiella subulata and Solieria robusta and hybrid iota/kappa carrageenan is expected to be present in Laurencia caraibica and Ahnfeltiopsis pygmaea. [ABSTRACT FROM AUTHOR]

Laurencia catarinensis (Ceramiales, Rhodomelaceae) has a high diversity of secondary metabolites such as acetogenin and halogenated terpenoids, with biological activities. We tested different combinations of auxins and cytokinins to evaluate their effects on the growth, total soluble proteins, pigments, and carbohydrates of L. catarinensis with the aim of improving the culture techniques of this species. To accomplish this, algae were cultivated in seawater enriched with quarter strength of von Stosch solution (VSES/4) with the addition of plant growth regulators (PGRs), and the treatment control without PGRs addition. The auxins tested were indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), and cytokinins were benzylaminopurine (BA) and 2-isopentenyladenine (2iP), in the following combinations: IAA:BA, IAA:2iP, 2,4-D:BA, and 2,4-D:2iP, in the concentrations of 5:5, 5:50, 50:5, and 50:50 μM for each auxin:cytokinin combination. Addition of PGRs had significant effects on the growth rates of L. catarinensis, which varied from 7.62 ± 0.12% to 9.30 ± 0.55% day−1. The highest growth rates were observed in treatments with 5:5 μM of IAA:BA and 2,4-D:BA, and 50:5 μM of 2,4-D:2iP. Higher contents of total soluble proteins were observed in treatments with 50:50 μM of IAA:BA and 2,4-D:BA. The auxin:cytokinin combinations inhibited allophycocyanin contents, but did not affect chlorophyll a and carbohydrate concentrations. Therefore, supplementation of auxins and cytokinins, especially the IAA:BA and 2,4-D:BA combinations, is useful approach to stimulate growth rates or soluble protein contents of L. catarinensis, improving the cultivation of this species with high biotechnological potential. [ABSTRACT FROM AUTHOR]

Insecticidal and repellent activities were evaluated on extracts from three macroalgae (Caulerpa sertularioides, Laurencia johnstonii and Sargassum horridum) against Diaphorina citri adults. The ethanolic extracts were obtained by maceration, filtration, and concentration under reduced pressure at 40 °C. Each extract was fractionated by solid-liquid methods, followed by column fractionation. The fractions obtained were analyzed by phytochemical tests to determinate their chemical composition. The three extracts showed alkaloids, terpenes, phenols, tannins, flavonoids, anthraquinones and saponins, which are associated with insecticidal and repellent activity. The repellency assay with S. horridum extract showed repellent activity over 24 h (Index of Behavioral Tendency, IBT = 0.376 ± 0.047), L. johnstonii extract showed repellency during 18 h (IBT = 0.240 ± 0.034). Although C. sertularioides extract at the beginning produced an attractant effect (during the first 4 h), it was followed by a repellent effect after 12 h (IBT = 0.297 ± 0.041). The repellent control used was Neemix 4.5 (azadirachtin) and it has a longer repellency of over the 24 h, however S. horridum had a higher repellent activity over the control during all the assay. In the insecticidal activity assay, lethal doses were calculated for each species: L. johnstonii (LD50 = 284 μg mL−1), S. horridum (LD50 = 364 μg mL−1), and C. sertularioides (LD50 = 3703 μg mL−1). Additionally, three terpenic compounds isolated from L. johnstonii were identified by GC/MS; debromolaurinterol, isolaurinterol, and laurinterol as potential insecticidal and repellent compounds. The results suggest that seaweed extracts represent an alternative in the development of agrochemicals for pest control. [ABSTRACT FROM AUTHOR]

Cittarium pica is an overexploited Caribbean top shell that is being produced at an experimental level by aquaculture for conservation purposes. To optimise nursery culture, the growth and survival of wild and hatchery-produced juveniles were assessed after feeding with different biofilm diets. The following three diets were tested over a 6-month period: (1) a microalgal biofilm of Nitzschia sp. and Tetraselmis chuii; (2) an artificial biofilm of dry seaweeds, Padina gymnospora and Laurencia obtusa, and the cyanobacterium Spirulina sp.; and (3) a mix of the microalgal and artificial biofilms. The biofilms were prepared and supplied on folded PVC plates, and treatments were administered in triplicated 10-L aquaria with down-welling systems at 25 ± 1 °C and a salinity of 36.5 ± 0.5 ppt. Higher growth rates were obtained in juveniles fed diets containing artificial biofilms, which had high protein and energy contents, whereas survival rates were higher in juveniles fed the mixed diet. The relatively high growth and survival values suggest that the nursery culture can be improved by feeding with the mix of microalgal and artificial biofilms and that the temporary translocation of wild juveniles to nursery conditions can be a tool for population enhancement. [ABSTRACT FROM AUTHOR]

Extracts of brown algae are used commercially for agricultural crops due to their plant growth-promoting effects and they can also be applied to help improve seaweed cultivation. Gracilaria caudata is commercially exploited as a raw material for agar production in Brazil, and Laurencia catarinensis is a source of halogenated terpenoids with several biological activities. Investigations to understand the development of seaweeds of biotechnological interest are required in order to improve their cultivation and the sustainability for biomass production on an industrial scale. The aim of the present study was to evaluate the effects of Ascophyllum/Acadian marine plant extract powder (AMPEP), a commercial, water-soluble extract of the brown alga Ascophyllum nodosum, on the growth, branching development, and pigment content of G. caudata and L. catarinensis. Four concentrations of AMPEP (0, 0.1, 1.0, and 5.0 mg L−1) were added to sterilized seawater (seawater+AMPEP), and to a medium comprised of half-strength von Stosch solution (VSES/2+AMPEP). Experiments were performed under conditions of 23 ± 2 °C, a light:dark cycle of 14:10 h, salinity at 32 psu, and photon flux densities of 60 ± 10 μmol photons m−2 s−1. Data were analyzed by one-way ANOVA, followed by a posteriori multiple comparison, Student-Newman-Keuls' test. Treatments of seawater+AMPEP at concentrations of 0.1 and 1.0 mg L−1 stimulated the growth rates of G. caudata when compared to the control. However, the effects of seawater+AMPEP and VSES/2+AMPEP on the branching architecture of the thalli were not significant for either species. Concentrations of phycoerythrin, phycocyanin, allophycocyanin, and chlorophyll-a in L. catarinensis were stimulated by the highest concentration of VSES/2+AMPEP (i.e., 5.0 mg L−1). This is the first study to report the stimulatory effect of AMPEP on the phycobiliprotein contents of selected red algae. Furthermore, seawater+AMPEP in concentrations of 0.1 and 1.0 mg L−1 stimulated growth rates of G. caudata, which could be applied in its large-scale cultivation. The results obtained for G. caudata and L. catarinensis, an agar-producing and a terpenoid-producing species, respectively, contributed to extending the knowledge of the beneficial uses of a brown seaweed-derived extract with biostimulatory properties for use with cultivated, economically important red algae. [ABSTRACT FROM AUTHOR]

Abstract This study was designed to characterize the physico-chemical properties of the sulfated polysaccharide (SP) isolated from the red alga Laurencia obtusa and to evaluate its apoptotic, gastroprotective and antioxidant activities. The different macromolecular characteristics of SP were determined by size exclusion chromatography combined with multi-angle laser light-scattering detection (SEC-MALLS), Fourier transform infrared spectroscopy (FTIR) analysis and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR). The native molecular weight of the extracted polysaccharide is high (≥336,900 g·mol−1). It showed high amounts of sulfated groups (28.2%) and low levels of proteins. It was found to be a potent inducer of apoptosis on acute monocytic leukaemia THP-1cell lines with EC 50 value of 53 μg·mL−1. Furthermore, a significant gastroprotective effect (p < 0.01) was also observed with a gastric ulcer inhibition of 63.44%, 78.42% and 82.15% at the doses 25, 50 and 100 mg·kg−1, respectively. In addition, SP significantly increased glutathione levels (GSH) and decreased the concentration of thiobarbituric acid-reactive substances (TBARS) in EtOH/HCl-damaged gastric mucosa in rats; it also exhibited an important antioxidant activity in vitro. Therefore, SP, derived from the red alga Laurencia obtusa, may have a potential therapeutic effect against acute myeloid leukaemia and a beneficial potential as gastroprotective and antioxidant natural product. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Induced chemical defense is still - uncertain process in seaweed, especially in tropical areas. Attention has been given to changes on phlorotannin contents due herbivore pressure, while knowledge considering - other secondary metabolites or other environmental factors as inducers is limited. We used laboratory experiments to assess induced chemical defense in the tropical red seaweed Laurencia dendroidea in response to simulated herbivory, presence of epibionts (microalga and bacterium), and bacterial infestation, addressing the following questions: 1) does inducible chemical defense by simulated herbivory, as well as microalgal and bacterial epibiosis, occur?; 2) are chemical defenses induced by bacterial infestation after simulated herbivory?; 3) is there a trade-off between inducible defense and seaweed growth?; and 4) how do variations in chemical defense affect seaweed susceptibility to specialist and generalist consumers? Inducible defense was measured as changes in sesquiterpene elatol levels, and growth was taken to infer whether induced chemical defense incurred metabolic costs. Specimens of L. dendroidea under simulated herbivory produced higher concentrations of elatol up to 2 days after treatment, followed by relaxation after 7 days, while epibiosis (by microalga and bacterium) and bacterial infestation did not induce a defense response. Simulated herbivory resulted in reduced L. dendroidea growth, reinforcing that induced chemical defense is a cost-saving strategy as stated by the Optimal Defense Theory (ODT), -in addition there was a tendency of epibiosis for biomass decreasing. The defensive effect varied according to elatol concentration and consumer identity, since aplysiids tolerated 10-fold natural concentrations (NC) whereas sea urchins were inhibited by NC. Our results highlight that inducible chemical defenses may also be a more rapid process than previously evidenced in seaweeds. Higher levels of elatol promoted decreased consumption, demonstrating that seaweed susceptibility is dose-dependent and induction is an important ecological strategy depending on environmental conditions. [ABSTRACT FROM AUTHOR]

Since the conception of the genus Laurencia by Lamouroux in 1813, several red macroalgal species have been included in it. In recent decades, the development of modern molecular tools has resulted in multiple taxonomic modifications, and presently, eight related genera are recognized in the so-called Laurencia complex. In the Macaronesian Region (Central East Atlantic Ocean), species from the Laurencia complex are keystone elements of the benthic communities, especially in the intertidal zone. In this review, we consolidate the existing knowledge about the Laurencia complex within the Macaronesian archipelagos and nearby areas. Morphological descriptions and phylogeographic remarks of the 16 currently accepted species--whose records were molecular or morphologically confirmed--are included together with an identification key for the Macaronesian Region. The phylogeographic data allowed us to re-visit the role of the Macaronesian archipelagos as a bridge area for the marine flora of the Mediterranean and Caribbean Seas (remnants of the former Thetyan Sea) or contemplate their marine flora as the result of successive processes of recolonization after the Quaternary glaciations from those donor areas. Finally, some comments about the frontiers of the research in the Laurencia complex in the Macaronesian Region and nearby coastal areas are included. [ABSTRACT FROM AUTHOR]

Chemical cues from sessile hosts can attract mobile and associated organisms and they are also impotant to maintain associations and overall biodiversity, but the identity and molecular structures of these chemicals have been little explored in the marine environment. Secondary metabolites are recognized as possible chemical mediators in the association between species of Laurencia and Aplysia, but the identity of the compounds has not been established. Here, for the first time, we experimentally verify that the sesquiterpene (+)-elatol, a compound produced by the red seaweed Laurencia dendroidea, is a chemical cue attracting the associated sea hare Aplysia brasiliana. In addition to revealing the nature of the chemical mediation between these two species, we provide evidence of a chemical cue that allows young individuals of A. brasiliana to live in association with L. dendroidea. This study highlights the importance of chemical cues in Laurencia-Aplysia association. [ABSTRACT FROM AUTHOR]

As marine tropical ecosystems deteriorate and lose biodiversity, their communities are shifting to being dominated by a few species, altering ecosystem's functioning and services. Macroalgae are becoming dominant on coral reefs, and are frequently observed outcompeting corals. Turf algal assemblages are the base of energy flow in these systems and one of the most abundant types of macroalgae on coral reefs, but little is known about their biology and diversity. Through molecular and morphological analyses, we identified the turf-forming species Laurencia cervicornis, and by studying seasonal recruitment and the impact of herbivorous fishes on its abundance, we describe its survival strategy. The molecular analyses used a total of 45 rbcL gene sequences including eight current genera within the Laurencia complex and two new sequences of L. cervicornis and strongly support the new combination of Palisada cervicornis comb. nov. In addition, a detailed morphological characterization including the description of reproductive structures is provided. Palisada cervicornis was seen recruiting in all seasons but was typically in low abundance. Specimens grown on tiles in fish exclosure cages were devoured in less than 4 h when offered to fishes. Even though many species of the Laurencia complex have chemicals that deter herbivory, species within the genus Palisada lack feeding deterrents and thus are highly palatable. We suggest that P. cervicornis is a palatable species that seems to survive in the community by obtaining a size-refuge from herbivory within turf communities. [ABSTRACT FROM AUTHOR]

Previous publications list ten species in the Laurencia complex from South Africa with all ascribed to the genus Laurencia sensu stricto. However, the diversity of the complex in South Africa has not yet been re-assessed following the numerous recent taxonomic changes. This study investigated the phylogenetic relationships and taxonomy of this group in South Africa using recent collections. Methods included molecular phylogenetic analyses of plastid rbcL gene sequences (a total of 146; including eleven outgroup taxa) using Maximum Likelihood and Bayesian Inference, and the examination of morphological and anatomical characters, including the number of corps en cerise when present. The seven genera of the Laurencia complex formed monophyletic clades with high posterior probabilities. Seventeen morphotypes were identified: 14 in the genus Laurencia sensu stricto, among which eight corresponded to Laurencia species currently recognized from South Africa and one each to species of Palisada, Chondrophycus, and Laurenciella. The six remaining morphotypes in Laurencia sensu stricto did not match any descriptions and are described here as five new species: Laurencia alfredensis sp. nov., Laurencia dichotoma sp. nov., Laurencia digitata sp. nov., Laurencia multiclavata sp. nov. and Laurencia sodwaniensis sp. nov. and a new variety: Laurencia pumila var. dehoopiensis var. nov . Laurencia stegengae nom. nov. is established to replace Laurencia peninsularis Stegenga, Bolton and Anderson nom. illeg. The diversity is likely greater, with six additional unidentified specimens found in this molecular investigation. These findings place South Africa alongside Australia in having one of the most diverse floras of this group in the world. [ABSTRACT FROM AUTHOR]

The first total synthesis of similisines A and B, a pair of unprecedented polybrominated spiro-trisindole enantiomers isolated from Laurencia similis , and their all stereoisomers had been accomplished in 6 steps from the known 5,6-dibromoindole. The described synthesis avoided any protecting-group manipulations, and the key all-carbon spirocenters were constructed via an intramolecular Friedel-Crafts cyclization. In addition, the rotamers of similisines and cytotoxic and NO production inhibitory activities of synthetic compounds were also discussed. [ABSTRACT FROM AUTHOR]

The marine red algae of the genus Laurencia have been widely studied for their structurally diverse and biologically active secondary metabolites. We report here the natural product investigation of the organic extract of a newly identified South African endemic species, Laurencia alfredensis. A sequence of column chromatography, preparative TLC and normal phase HPLC resulted in the isolation of eleven compounds comprising three labdane-type diterpenes (1-3), four polyether triterpenes (4-7), three cholestane-type ecdysteroids (8-10) and a glycolipid (11). Compounds 1-3, 5-8 and 10 have not previously been reported, while compound 9 is reported here for the first time from a natural source and the known compound 11 isolated for the first time from the genus Laurencia. The structural elucidation and the relative configuration assignments of the compounds were accomplished by extensive use of 1D- and 2D-NMR, HR-ESI-MS, UV and IR spectroscopic techniques, while the absolute configuration of compound 1 was determined by single-crystal X-ray diffraction analysis. All compounds were evaluated against the MDA-MB-231 breast and HeLa cervical cancer cell lines. Compound 2 exhibited low micromolar antiproliferative activity (IC50 = 9.3 μM) against the triple negative breast carcinoma and compound 7 was similarly active (IC50 = 8.8 μM) against the cervical cancer cell line. [ABSTRACT FROM AUTHOR]

SUMMARY Laurencia majuscula has recently been determined to be conspecific with Laurencia dendroidea. To determine the correct taxonomic placement of its only non-typical variety, L. majuscula var. elegans, mitochondrial COI-5P and chloroplast rbcL gene sequences were analyzed and its phylogenetic position was inferred. Laurencia majuscula var. elegans consistently formed a well-supported clade distinctly separate from the L. dendroidea clade. Molecular analyses revealed that L. majuscula var. elegans generally shows two distinct forms; a long-branched form, and a compact form. Often the compact form has been identified as a different species based on morphology alone. Included in these analyses were topotype sequences of two species with which L. majuscula var. elegans is most often misidentified; Laurencia nidifica and Laurencia mcdermidiae. Laurencia nidifica formed a well-supported clade separate from L. majuscula var. elegans. Laurencia mcdermidiae, however, formed a well-defined clade sister to the L. majuscula var. elegans clade. Morphological comparisons were also made. It is concluded that L. majuscula var. elegans is morphologically distinct from L. dendroidea, L. nidifica, and L. mcdermidiae. It is proposed that L. majuscula var. elegans be reinstated to species level as L. elegans. [ABSTRACT FROM AUTHOR]

Recently, the phenomenon of enantiodivergence was uncovered as a new phenomenon in the biosynthesis of natural products. In nature, chiral natural products are usually produced in optically active form, but both enantiomers sometimes arise in different genera and/or species or in a single species. Here we show through enantioselective total synthesis that the natural product isodehydrothyrsiferol shows partial enantiodivergency in that six of the nine or ten asymmetric centers are enantiomeric to those of other members of the marine squalene-derived triterpenoid thyrsiferol family. In addition, isodehydrothyrsiferol and dehydrothyrsiferol, which show partial enantiodivergency, were isolated from the same producer, the red alga Laurencia viridis. These results demonstrate that partial enantiodivergence can develop even between natural products originating from a single species. [ABSTRACT FROM AUTHOR]

An ethyl acetate (EtOAc) extract of Laurencia nidifica was found to have toxic effect against brine shrimp larvae (Artemia salina). Bioassay-guided fractionation of the EtOAc extract resulted in the isolation of four known halogenated sesquiterpenes, laurinterol (1), isolaurinterol (2), aplysin (3), and α-bromocuparene (4). Their structures were established on the basis of spectral analysis and comparison with literature data. Among isolated compounds, only laurinterol showed strong toxicity against A. salina. Further experiments revealed that laurinterol also exhibited repellent activity against the maize weevil Sitophilus zeamais, insecticidal activity against the termite Reticulitermes speratus, and acetylcholinesterase (AChE) inhibitory effect. This is the first report of insecticidal and repellent activities of laurinterol. [ABSTRACT FROM AUTHOR]

The red seaweed Laurencia dendroidea belongs to the Rhodophyta, a phylum of eukaryotic algae that is widely distributed across the oceans and that constitute an important source of bioactive specialized metabolites. Laurencia species have been studied since 1950 and were found to contain a plethora of specialized metabolites, mainly halogenated sesquiterpenes, diterpenes and triterpenes that possess a broad spectrum of pharmacological and ecological activities. The first committed step in the biosynthesis of triterpenes is the cyclization of 2,3-oxidosqualene, an enzymatic reaction carried out by oxidosqualene cyclases (OSCs), giving rise to a broad range of different compounds, such as the sterol precursors cycloartenol and lanosterol, or triterpene precursors such as cucurbitadienol and β-amyrin. Here, we cloned and characterized the first OSC from a red seaweed. The OSC gene was identified through mining of a L. dendroidea transcriptome dataset and subsequently cloned and heterologously expressed in yeast for functional characterization, which indicated that the corresponding enzyme cyclizes 2,3-oxidosqualene to the sterol precursor cycloartenol. Accordingly, the gene was named L. dendroidea cycloartenol synthase (LdCAS). A phylogenetic analysis using OSCs genes from plants, fungi and algae revealed that LdCAS grouped together with OSCs from other red algae, suggesting that cycloartenol could be the common product of the OSC in red seaweeds. Furthermore, profiling of L. dendroidea revealed cholesterol as the major sterol accumulating in this species, implicating red seaweeds contain a ‘hybrid’ sterol synthesis pathway in which the phytosterol precursor cycloartenol is converted into the major animal sterol cholesterol. [ABSTRACT FROM AUTHOR]

The first asymmetric total synthesis and subsequent structure revision of (-)-bisezakyne A, a Laurencia C15 acetogenin from Alpysia oculifera, has been accomplished. Our substrate-controlled synthesis of this oxolane natural product features a highly stereoselective "protecting-group-dependent" intramolecular amide enolate alkylation strategy for the synthesis of the key 9,10-trans-9,12-cis-10-hydroxytetrahydrofuran intermediate through "nonchelate" control. In addition, our synthesis determined the absolute configuration of the halogenated marine natural product. [ABSTRACT FROM AUTHOR]

Four new minor brominated indole related alkaloids (one indoles, 1 , one 1,3-dihydro-indole-2-one, 2 , one carbazole, 3 , and one 2-carbonylamino-benzoate, 4 ) were isolated and identified from Laurencia similis by extensive chromatographic and spectrometric methods. Among them, 1 and 2 were the first example of naturally occurring indole with 3-benzyl group and 1,3-dihydro-indole-2-one with 2-isopropylidene group, respectively, whereas 3 and 4 were the first carbazole alkaloids and 2-carbonylamino-benzoate, respectively, isolated from the genus Laurencia. Moreover, 1 showed the most potent antibacterial activity against seven bacterial strains with MIC values ranging from 2 to 8 μg/mL. [ABSTRACT FROM AUTHOR]

Response surface methodology was used to investigate the effect of ultrasound-assisted extraction conditions including solvent:seaweed ratio (10:1–30:1), extraction temperature (30–50°C), and extraction time (30–60 min) on the total phenolic compounds and antioxidant activity of red seaweed (Laurencia obtuse) extracts. The optimum extraction parameters for maximum phenolic content were as follows: solvent:seaweed ratio, 30:1; extraction temperature, 50°C; and extraction time, 42.8 min. The experiment results showed that the solvent:seaweed ratio was the most significant parameter for the extraction. The optimum extraction conditions for maximum antioxidant activity were as follows: solvent:seaweed ratio, 24.3:1; extraction temperature, 45.3°C; and extraction time, 58 min. Under the above-mentioned conditions, the experimental total phenolic content and antioxidant activity value were 26.23 ± 0.75 mg GAE/g seaweed and 120.89 ± 0.81 TEAC, respectively, of seaweed tested, which are well compatible with the predicted contents. [ABSTRACT FROM AUTHOR]

Background: Red algae of the genus Laurencia J. V. Lamouroux are a rich source of secondary metabolites with important pharmacological activities such as anti-tumoral, anti-inflammatory, anti-fungal, anti-viral, anti-leishmanial, anti-helminthic, anti-malarial, anti-trypanosomal, anti-microbial as well as anti-bacterial against Mycobacterium tuberculosis. Objective: In the present study, we evaluated the inhibition of nitric oxide (NO) and tumor necrosis factor-α production and the anti-mycobacterial activity of crude extracts from the red Alga Laurencia dendroidea (from the South-Eastern coast of Brazil). Halogenated sesquiterpenes elatol (1), obtusol (2) and cartilagineol (3), previously isolated from this Alga by our group, were also studied. Materials and Methods: The lipopolysaccharide-activated macrophage cells (RAW 264.7) were used as inflammation model. Cytotoxic effect was determined using a commercial lactate dehydrogenase (LDH) kit and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The growing Mycobacterium inhibition was verified against Mycobacterium bovis Bacillus Calmette–Guérin and M. tuberculosis H37Rv strains. Results: The crude extract from Alga collected at Angra dos Reis, RJ, Brazil, was the most active inhibitor of both mycobacterial growth (half maximal inhibitory concentration [IC50] 8.7 ± 1.4 μg/mL) and NO production by activated macrophages (IC50 5.3 ± 1.3 μg/mL). The assays with isolated compounds revealed the anti-mycobacterial activity of obtusol (2), whereas (-)-elatol (1) inhibited the release of inflammatory mediators, especially NO. To our knowledge, this is the first report describing an anti-mycobacterial effect of L. dendroidea extract and demonstrating the association of this activity with obtusol (2). Conclusion: The described effects of active compounds from L. dendroidea are promising for the control of inflammation in infectious diseases and specifically, against mycobacterial infections associated with exacerbated inflammation. [ABSTRACT FROM AUTHOR]

Variability in the production of secondary metabolites by seaweeds is commonly measured under natural conditions and is usually considered a response to environmental factors. However, it is not well known if levels of secondary metabolites can vary due to internal regulation of physiological processes. We measured the diel levels of elatol - the major defensive compound of Laurencia dendroidea - in correlation with the activity of photosystem II (Φ PSII ) in clones of this seaweed cultivated under constant conditions of temperature, salinity, nutrient availability and irradiance. Our results showed temporal variation in amounts of elatol, which peaked at the beginning of the light and dark periods. The Φ PSII during the light phase, as measured by chlorophyll fluorescence imaging, was higher when the elatol concentration was lower. We conclude that under constant conditions, i.e. without the influence of natural habitat and genetic variability, there is diel variation in elatol production that is inversely correlated with Φ PSII . We suggest that both metabolic activity of secondary metabolite production and photosynthetic activity are under an endogenous control in this red seaweed. We discuss the possible adaptive responses of this phenomenon to environmental pressures. [ABSTRACT FROM AUTHOR]

Chemical investigation of the marine red alga Laurencia pinnata collected from Nanji Island of China resulted in the isolation and identification of three new eudesmane (selinane) sesquiterpenes, 1β-bromoselin-11-en-4α-ol ( 1 ), 1β-bromo-4α,5α-epoxyselinane ( 2 ), and 1β-bromoselin-3,11-diene ( 3 ), and one new 6,8-cycloeudesmane sesquiterpene, 1β-bromo-6,8-cycloselin-4(15)-ene ( 4 ), together with one known eudesmane sesquiterpene, 1β-bromoselin-4(15),11-diene ( 5 ), two known chamigrane sesquiterpenes, 2,10-dibromo-3-chlorochamigr-7-ene ( 6 ) and 2,10-dibromo-3-chlorochamigr-7-en-9-ol ( 7 ), one kahukuane diterpene, kahukuene B ( 8 ), and one parguerane diterpene, 15-bromoparguer-9(11)-en-16-ol ( 9 ). These halogenated isolates were found in L . pinnata for the first time, and they support the taxonomic position of this species under the genus Laurencia . Eudesmane derivatives ( 1 – 5 ) are predominant and rarely reported from this genus, and they may be taken as chemotaxonomic markers for L. pinnata in the future. [ABSTRACT FROM AUTHOR]

The present study described with different microscopy approaches chloroplasts lobes in Laurencia sensu latu (Rhodophyta) species and found inter-specific differences among them. Chloroplasts were investigated using confocal laser scanning microscopy (LSM), transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HRSEM). Using and TEM and HRSEM images we distinguished chloroplasts with lobes than chloroplasts without lobes in Yuzurua poiteaui var. gemmifera (Harvey) M. J. Wynne and Laurencia dendroidea J. Agardh cortical cells. The LSM images showed chloroplasts lobes (CLs) with different morphologies, varying from thicker and longer undulated projections in Y. poiteaui var. and L. dendroidea to very small and thin tubules as in Laurencia translucida Fujii & Cordeiro-Marino. The diameter and length of CLs from Y. poiteaui var. and L. dendroidea were significantly higher than L. translucida CLs (p < 0.01). Based on LSM observations, we suggest that lobes morphology has a taxonomic validity only to characterize L. translucida species. [ABSTRACT FROM AUTHOR]

A new Bis-sesquiterpene, Nanji A ( 1 ), has been isolated together with 7 known compounds, debromolaurinterol ( 2 ), laurinterol ( 3 ), laurinterol acetate ( 4 ), isolaurinterol ( 5 ), 3α-hydroperoxy-3-epiaplysin ( 6 ), 3β-hydroperoxyaplysin ( 7) , Laurokomurenene A ( 8 ), from the Nanji red alga Laurencia okamurai . The structure of 1 was elucidated on the basis of extensive spectroscopic analysis of its EIMS, 1D and 2D NMR data. Furthermore, the chemotaxonomic significance of these compounds was also summarized. [ABSTRACT FROM AUTHOR]

Within the Laurencia complex (Rhodophyta, Rhodomelaceae), six genera have been recognized based on both molecular analyses and morphology: Laurencia, Osmundea, Chondrophycus, Palisada, Yuzurua, and Laurenciella. Recently, new material from Australia has been collected and included in the current molecular phylogeny, resulting in a new clade. This study examined the generic delineations using a combination of morphological comparisons and phylogenetic analysis of chloroplast ( rbcL) nucleotide sequence. The molecular phylogeny recovered eight (rather than six) clades; Yuzurua, Laurenciella, Palisada, and Chondrophycus showed as monophyletic clades each with strong support. However, the genera Osmundea and Laurencia were polyphyletic. Consequently, the new genus Coronaphycus is proposed, resulting in the new combination Coronaphycus elatus and a description of the new species C. novus. [ABSTRACT FROM AUTHOR]

The sterol content of Laurencia obtusa var. pyramidata (Hudson) J. V. Bory ex. J. Agardh collected from Igneada, in the western part of the Black Sea coast of Turkey, was analyzed. They were cholest-5-en-3-ol (cholesterol), β-sitosterol, ergosta-5,7,22-trien-3- ol (ergosterol), 24-norcholesta-5,22(E)-dien-3β-ol, cholest-5,22(E)-dien-3β-ol, ergosta- 5,24(28)-dien-3β-ol, 27-norergosta-5,22(E)-dien-3β-ol, ergosta-5, 22(E)-dien-3-ol, 23(S)- methylcholesterol, 23(S)-ethylcholesterol. The latter four were found in Laurencia species for the first time. [ABSTRACT FROM AUTHOR]

Sierra Los Tanques is located in NW Sonora, Mexico, and represents one of the main outcrops of Permo-Triassic granitic rocks reported in the region. U-Pb zircon geochronology conducted in two groups of granitoids from various locations in NW Sonora provide a range of ages between 284 - 221 Ma. Rock types are dominated by granodiorite, followed by quartzmonzodiorites, and monzogranites. There are two main granitic suites-leucocratic and melanocratic granitoids. Field relationships between the two types suggests that the melanocratic granitoids are older as they are clearly intruded by the leucocratic suite. This field evidence is supported, in most cases, by the U-Pb zircon ages obtained in samples of both granitic suites. Most of the zircons from these Permo-Triassic granitoids have high U concentrations (~ 47 - 9508 ppm), suggesting significant Pb loss in their crystal structure. The Permo-Triassic zircons show highly variable Th/U ratios (0.01 - 0.73). These zircons have an igneous origin not only because of their prismatic morphologies, but also due to their oscillatory zoning characteristic of magmatic growth as observed in cathodoluminescence studies. The presence of inherited cores, as shown in cathodoluminescence images, can be associated with the ages of meta-igneous Proterozoic basement present in Sierra Los Tanques (~ 1.7 - 1.6 Ga, ~ 1.4 Ga and ~ 1.1 Ga) that could have been incorporated during magma-genesis in Permo-Triassic time. These granitoids associated with subduction give evidence for the beginning of cordilleran arc magmatism in SW North America (Laurentia) established along the western margin of Pangea immediately following the latest stages of the collision between Laurentia and Gondwana. This Permo-Triassic magmatism is important for understanding the tectonic evolution of NW Mexico. Tentatively, the occurrence of this magmatism is associated with a zone of crustal weakness spatially associated with the Mexican Yavapai basement province in NW Sonora. Understanding this magmatic pulse is also of particular importance as it represents a regional source of detrital Permo-Triassic zircons previously unrecognized for Mesozoic and Cenozoic sedimentary basins in Sonora and southern Arizona. Lastly, this Permo-Triassic subduction-related magmatic pulse present in NW Sonora is part of a larger magmatic arc event along the American Cordillera that extends from western-southwestern United States, passing through northern, central, and southern Mexico and reaching northern South America. [ABSTRACT FROM AUTHOR]

Earlier four brominated sesquiterpenes, aldingenins A–D, were isolated from the red algae Laurencia aldingensis , and their structure elucidated by spectroscopic methods including NMR. Total syntheses of the proposed structures of aldingenin B ( Org. Lett. 2012 , 14 , 2168) and aldingenin C ( J. Org. Chem. 2014 , 79 , 9373) have demonstrated that the structures are misassigned. Koshino has proposed aldingenins C and D to be caespitol and 5-( S )-acetoxycaespitol. Computational evidence presented in this Letter and based primarily on the computed proton spin–spin coupling constants (but also including 13 C NMR chemical shifts) leads to the conclusion that the remaining two aldingenins A and B are also halogenated sesquiterpenes of the same caespitol family. Aldingenin A is assigned the structure of 5-( S )-hydroxycaespitol 1 , and aldingenin B—hemiacetal 2 of a related 8-oxo compound. [ABSTRACT FROM AUTHOR]

The red alga Gayliella fimbriata (Ceramiaceae, Rhodophyta) is reported for the first time from the Mediterranean Sea. This species was collected growing as an epiphyte on Laurencia obtusa in the sublittoral zone at Antalya (Mediterranean coast of Turkey). Gayliella fimbriata is characterized by its protruding clavate gland cells. Features to distinguish the four Turkish species of Gayliella from one another are provided. [ABSTRACT FROM AUTHOR]

We present the 174,935 nt long plastid genome of the red alga Laurencia sp. JFC0032. It is the third plastid genome characterized for the largest order of red algae (Ceramiales). The circular-mapping plastid genome is small compared to most florideophyte red algae, and our comparisons show a trend toward smaller plastid genome sizes in the family Rhodomelaceae, independent from a similar trend in Cyanidiophyceae. The Laurencia genome is densely packed with 200 annotated protein-coding genes (188 widely conserved, 3 open reading frames shared with other red algae and 9 hypothetical coding regions). It has 29 tRNAs, a single-copy ribosomal RNA cistron, a tm RNA, and the RNase P RNA. [ABSTRACT FROM AUTHOR]

The Mediterranean coast of Israel is well known as a hotspot of invasive marine species, mostly from the Indian and Pacific oceans. Here, we report the first occurrence of the red seaweed Laurencia chondrioides in the eastern Mediterranean Sea. Large quantities of this species were observed in the algal drift on the sandy shores as well as on rocky surfaces of the upper and middle infralittoral zone. This highly abundant invasive species, present along the northern shore of Israel, represents a serious threat to the local marine flora. Some aspects of its ecology and invasive behavior in this region are also discussed. [ABSTRACT FROM AUTHOR]

Three new sesquiterpene alcohols, laur-2-ene-3,12-diol ( 1), cuparene-3,12-diol ( 2), and 8,11-dihydro-1-methoxylaurokamuren-12-ol ( 3), along with one known diterpene, kahukuen-10-ol ( 4) have been isolated from the organic extract of the red alga Laurencia obtusa. The chemical structures were elucidated on the basis of spectroscopic analysis. The cytotoxicity of the isolated compounds were evaluated against three cancer cell lines, i.e., KB, HepG2, and MCF-7. Compound 4 exhibited a wide range of cytotoxic activity against KB, HepG2, and MCF-7 cell lines with IC50 of 0.100, 0.057, and 0.054 μ m, respectively. In addition, 1 showed moderate activities towards KB and MCF-7 cell lines with IC50 values of 0.171 and 0.184 μ M, respectively and 2 exhibited a moderate activity against KB cell line at a concentration of 0.213 μg/ml. On the other hand, compound 3 exhibited no cytotoxic activity against any of the three cell lines. [ABSTRACT FROM AUTHOR]

The article presents a study which cloned the cDNA for red alga Laurencia nipponica vanadium-dependent bromoperoxidases (LnVBPO) in Escherichia coli. The methods include RNA preparation for the alga, the synthesis of double stranded cDNA (dscDNA), and construction fo gene expression plasmids. The study also examined the purified recombinant LnVBPO proteins, algal BPO native proteins and peptide sequence analysis, and the bromination of monochlorodimedone MCD).

Highlights: [•] A seco-laurane sesquiterpene and related laurane derivatives were isolated from Laurencia okamurai. [•] One compound possesses an unprecedented carbon skeleton named seco-laurokamurane. [•] Another compound represents the fourth example of a laurokamurane-type sesquiterpene in nature. [•] Some isolates exhibited moderate antifungal activity against four clinical fungi. [•] Two of eleven compounds showed moderate cytotoxicity against two human cancer cell lines. [Copyright &y& Elsevier]

Natural antifouling products have been the subject of considerable attention. We screened marine algae for antifouling activity and discovered omaezallenes, the new bromoallene-containing natural products isolated from the red alga Laurencia sp. Described is the isolation, structure elucidation, and total syntheses of omaezallenes. The relative and absolute configurations of natural omaezallenes were unambiguously established through total synthesis. The antifouling activities and ecotoxicity of omaezallenes were also evaluated. [ABSTRACT FROM AUTHOR]

Natural antifouling products have been the subject of considerable attention. We screened marine algae for antifouling activity and discovered omaezallenes, the new bromoallene-containing natural products isolated from the red alga Laurencia sp. Described is the isolation, structure elucidation, and total syntheses of omaezallenes. The relative and absolute configurations of natural omaezallenes were unambiguously established through total synthesis. The antifouling activities and ecotoxicity of omaezallenes were also evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Methanol extract of thirty-eight seaweeds samples were first screened against Gram-positive (Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6051) and -negative (Escherichia coli ATCC 8739 and Pseudomonas aerugenosa ATCC 9027) bacteria. Laurencia papillosa (Ceramiales, Rhodomelaceae, Rhodophyta) gave maximum antimicrobial activity against these bacteria. It was finally tested against four clinical Gram-negative isolates (E. coli, P. aerugenosa, Klebsiella pneumoniae and Shigella flexineri) and exhibited antibacterial activity. The extract was fractionated by column chromatography and the active fraction was identified as a cholesterol derivative, 24-propylidene cholest-5-en-3β-ol using gas chromatography mass spectrometry (GC–MS). The electrospray ionization mass spectrometry (ESI-MS) and FT-IR spectroscopic analysis also supported the structure of the compound. The minimum inhibitory concentration ranged from 1.2 to 1.7μg/mL (IC50) against clinical isolates. This is the first report of antibacterial activity of this cholesterol derivative. This compound could be exploited as potential lead molecule against broad spectrum drug development. The results also affirm the potential of seaweeds as an important natural source of antimicrobial compounds for pharmaceutical industries. [Copyright &y& Elsevier]

Red algae genus Laurencia is an interesting alga with the ability to produce halogenated secondary metabolites that exhibits ecological and pharmaceutical potential. In nature, Laurencia is selectively grazed by sea hares ( Aplysia dactylomela). In this study, Laurencia populations in three islands (Mantanani, Sulug, and Dinawan Islands) in the coastal waters of North Borneo were investigated and their chemical relationship with sea hare determined. Four species of Laurencia were found to grow abundantly in these waters, Laurencia snackeyi, Laurencia majuscula, Laurencia nangii, and Laurencia similis. Sea hares, Aplysia dactylomela, found grazing on Laurencia were collected and their chemical composition determined. A total of 20 halogenated metabolites were isolated and identified via spectroscopic data. Isolated compounds could be grouped into syndrean (5), chamigrane (6), non-chamigrane sesquiterpene (3), cuparane (1), bromoindole (2), and C15 acetogenin (acetylene type) (3). Sea hares from Mantanani, Sulug, and Dinawan Islands contained a total of 9, 10, and 10 compounds, respectively. In addition, 12-acetoxypalisadin B (1), which was isolated from sea hares of Sulug Island is a first record of its existence in nature. [ABSTRACT FROM AUTHOR]

The use of CE- ESI- MS has been considered as a new chemical strategy for the possible discernment of genera and species of the Laurencia complex. After the selection of the CE- MS and the extraction conditions, a total of 28 specimens of the complex, including different species of four genera ( Laurencia, Laurenciella, Palisada, and Osmundea) collected from five intertidal locations on the Island of Tenerife ( Canary Islands, Spain) were analyzed. CE- MS fingerprints revealed that CE- MS can be used as a useful tool for these studies in order to assess similarities and differences between them and that it constitutes an important starting point for further studies in the field. [ABSTRACT FROM AUTHOR]

Two new chamigrane sesquiterpenes 1-2 and three known compounds 3-5 were isolated from a lipophilic extract of the red alga Laurencia dendroidea collected from the Southeastern Brazilian coast. Dendroidone (1) and dendroidiol (2) were isolated from samples collected at Biscaia Inlet, Angra dos Reis, Rio de Janeiro and at Manguinhos Beach, Serra, Espírito Santo, respectively. Debromoelatol (3), obtusane (4) and (1S*,2S*,3S*,5S*,8S*,9S*)-2,3,5,9-tetramethyltricyclo[6.3.0.01.5]undecan-2-ol (5) were obtained from specimens collected at Vermelha Beach, Parati, Rio de Janeiro. The structures of new compounds were elucidated by extensive NMR (1H-, 13C-, COSY, HSQC, HMBC and NOESY) and high resolution mass spectrometry analysis. Additionally, the absolute configuration of compound 2 was assigned by X-ray analysis. Full spectroscopic data is described for the first time for compound 3. Anti-inflammatory and antimycobacterial activities of compounds 2-5 were evaluated. Compounds 3-5 inhibited the release of inflammatory mediator NO while TNF-α levels were only affected by 3. All compounds tested displayed moderate antimycobacterial action. [ABSTRACT FROM AUTHOR]

In the present study we undertook an integrative approach, using both morphological and molecular data (COI-5P +rbcL), to assess the presence ofLaurencia pyramidalisin Lusitanian Macaronesia. We studied type material ofL. pyramidalisfrom the herbarium of the Naturalis Biodiversity Center, the Netherlands, and designated a lectotype and syntypes. Vegetative and reproductive features ofL. pyramidaliswere observed and we included a specimen from the type locality in our molecular analyses. We also investigated the geographical distribution ofLaurenciella marilzae, a species recently described from the Canary Islands. Barcode sequences (COI-5P andrbcL) were generated forL. pyramidalisfrom the type locality (Normandy, France), the Azores, Madeira and the Canary Islands, and forL. marilzaefrom its type locality (Tenerife, Canary Islands), the Azores and Brazil. [ABSTRACT FROM PUBLISHER]