Abstract Marine organisms produce a variety of compounds with pharmacological activities. In order to better comprehend the medicinal value of five particular seaweed orders Ulvales (Ulva intestinalis), Bryopsidales (Codium decorticatum), Ectocarpales (Iyengaria stellata), Dictyotales (Spatoglossum aspermum) and Gigartinales (Hypnea musciformis), a bioactive analysis including the screening of phytochemical components, antioxidant and antimicrobial activities was the aim of the investigation. The species include U. intestinalis was collected from Sandspit, while C. decorticatum, I. stellata, S. aspermum, and H. musciformis were gathered from Buleji. These species evaluated for their ability to inhibit human infectious gram positive pathogens Staphylococcus aureus, Staphylococcus epidermidis as well as gram negative bacteria Escherichia coli. Additionally vegetable pathogen Fusarium oxysporum, and fruit pathogens (Aspergillus niger and Aspergillus flavus) were evaluated to determine the zone of inhibition. Two organic solvents, ethanol and methanol, were used to prepare seaweed extract. The disc diffusion method was utilized to quantify the zone of inhibition and the DPPH method was employed to measure the antioxidant activity. The study unveiled various phyto-constituents in the tested seaweeds, with flavonoids, tannins, and proteins found in all selected species, while saponins, terpenoids, and carbohydrates were absent in I. stellata and S. aspermum. Notably, ethanolic extracts of I. stellata and S. aspermum demonstrated superior higher antioxidant activity, with increasing percentages of inhibition from 1 to 6 mg/ml. Furthermore, the findings indicated that the ethanolic extract of U. intestinalis displayed the highest resistance against F. oxysporum and A. flavous among other seaweeds. Meanwhile, the ethanolic extract of C. decorticatum exhibited the highest resistance against A. Niger. Additionally, the ethanolic extract of I. stellata and H. musciformis displayed the highest resistance against the gram-negative bacteria E. coli and the gram-positive bacteria S. epidermidis, whereas the methanolic extract of U. intestinalis demonstrated the highest resistance against the gram-positive bacteria S. aureus. The findings of this investigation show that a range of bioactive compounds with antioxidant properties are involved in the antimicrobial activities of disease-causing pathogens. Ulva intestinalis, , intestinalis) Codium decorticatum) Iyengaria stellata) Spatoglossum Hypnea musciformis, musciformis) components U Sandspit C I S H Buleji aureus flavus solvents methanol activity phytoconstituents phyto constituents seaweeds flavonoids tannins saponins terpenoids Notably mgml mg ml mg/ml Furthermore F A Meanwhile Niger gramnegative E grampositive diseasecausing disease causing

Resumo Os organismos marinhos produzem uma variedade de compostos com atividades farmacológicas. Para melhor compreender o valor medicinal de cinco ordens específicas de algas marinhas – Ulvales (Ulva intestinalis), Bryopsidales (Codium decorticatum), Ectocarpales (Iyengaria stellata), Dictyotales (Spatoglossum aspermum) e Gigartinales (Hypnea musciformis) –, o objetivo desta investigação foi fazer uma análise bioativa, incluindo a triagem de componentes fitoquímicos, atividades antioxidantes e antimicrobianas. As espécies U. intestinalis foram coletadas em Sandspit, enquanto C. decorticatum, I. stellata, S. aspermum e H. musciformis foram coletadas em Buleji. Estas espécies foram avaliadas quanto à sua capacidade de inibir os patógenos Gram-positivos infecciosos humanos Staphylococcus aureus e Staphylococcus epidermidis, bem como as bactérias Gram-negativas Escherichia coli. Além disso, o patógeno vegetal Fusarium oxysporum e os patógenos de frutas Aspergillus niger e Aspergillus flavus foram avaliados para determinar a zona de inibição. Dois solventes orgânicos, etanol e metanol, foram utilizados para preparar o extrato de algas marinhas. O método de difusão em disco foi utilizado para quantificar a zona de inibição, e o método DPPH foi empregado para medir a atividade antioxidante. O estudo revelou vários fitoconstituintes nas algas testadas, com flavonoides, taninos e proteínas encontrados em todas as espécies selecionadas, enquanto saponinas, terpenoides e carboidratos estavam ausentes em I. stellata e S. aspermum. Notavelmente, os extratos etanólicos de I. stellata e S. aspermum demonstraram maior atividade antioxidante, com percentagens crescentes de inibição de 1 a 6 mg/ml. Além disso, os resultados indicaram que o extrato etanólico de U. intestinalis apresentou a maior resistência contra F. oxysporum e A. flavus, entre outras algas marinhas. Enquanto isso, o extrato etanólico de C. decorticatum teve maior resistência contra A. Niger. Além disso, o extrato etanólico de I. stellata e H. musciformis apresentou a maior resistência contra as bactérias Gram-negativas E. coli e as bactérias Gram-positivas S. epidermidis, enquanto o extrato metanólico de U. intestinalis demonstrou a maior resistência contra a bactéria Gram-positiva S. aureus. Os resultados desta investigação mostram que uma série de compostos bioativos com propriedades antioxidantes está envolvida nas atividades antimicrobianas de patógenos causadores de doenças. farmacológicas Ulva intestinalis, , intestinalis) Codium decorticatum) Iyengaria stellata) Spatoglossum Hypnea bioativa fitoquímicos U Sandspit C I S H Buleji Grampositivos Gram positivos epidermidis Gramnegativas negativas disso orgânicos metanol antioxidante testadas flavonoides selecionadas saponinas Notavelmente mgml mg ml mg/ml F A isso Niger E Grampositivas positivas Grampositiva positiva doenças

Resumen Las especies de Lobophora (Dictyotales) se distribuyen en mares tropicales y subtropicales del mundo. Estudios recientes revelaron una alta diversidad de especies en regiones en las que se había reportado únicamente una especie, como el mar de Bismarck, Pacífico oriental, Atlántico occidental, mar Mediterráneo y el gran Caribe. En este estudio, se recolectaron ejemplares de Veracruz y Quintana Roo, México, y se secuenciaron 2 genes (cox3 y psbA). Los resultados confirmaron la presencia de L. dispersa y L. variegata. Lobophora dispersa se reporta por primera vez en la costa mexicana. La distribución de sus haplotipos muestra diferenciación genética dentro del gran Caribe y golfo de México, posiblemente indicando dispersión limitada y aislamiento por distancia. Lobophora variegata es menos variable y sus haplotipos no muestran un patrón definido. Lobophora declerckii, reportada en el arrecife "Anegada de Afuera", Veracruz, no fue encontrada, posiblemente debido a su afinidad por profundidades submareales. Morfológicamente, L. dispersa y L. variegata concuerdan con descripciones previas, aunque se encontró mayor variación en el grosor del talo en L. dispersa. Sin embargo, la morfología es insuficiente para determinar las especies con confianza, requiriendo un mayor muestreo para conocer la diversidad de especies en México.

Abstract Species of Lobophora (Dictyotales) are distributed throughout the sub-tropical and tropical seas worldwide. Recent analyses have revealed high species diversity in regions previously presumed to host only a single species, such as the Bismarck Sea, Eastern Pacific, Western Atlantic, Mediterranean Sea, and Greater Caribbean. Here, samples from Veracruz and Quintana Roo, Mexico, were collected, and 2 genetic markers (cox3 and psbA) were sequenced. The results confirmed the presence of L. dispersa and L. variegata. Lobophora dispersa is recorded for the first time on the Mexican coast. The distribution of its cox3 haplotypes shows genetic differentiation within the Greater Caribbean and Gulf of Mexico, possibly indicating limited dispersal and isolation by distance. Lobophora variegata exhibits lower genetic variability compared to L. dispersa, but its haplotypes did not show any obvious pattern. Lobophora declerckii, previously reported in the "Anegada de Afuera" reef, Veracruz, was not found, possibly due to its affinity to subtidal depths. Morphologically, L. dispersa and L. variegata align with previous descriptions, although we observed more variation in thallus cell thickness in L. dispersa. However, relying solely on morphological characters is insufficient to confidently identify the species, necessitating further sampling to determine the species diversity in Mexico.

Abstract Intraspecific variation on meroditerpenoids production by the brown marine alga Stypopodium zonale at four different populations along the Brazilian coast was analyzed using Principal Component Analysis over high-performance liquid chromatography profiles from algae extracts. The ordination of the samples by the similarities of their chromatographic traits showed the existence of three chemotypes: (i) the populations Búzios and Abrolhos which were characterized by the presence of atomaric acid (1), (ii) the population Atol das Rocas which contained the compound stypoldione (2), and (iii) the population Marataízes which was characterized by other peaks that guided the isolation of three new meroditerpenoids stypofuranlactone (3), 10,18-dihydroxy-5′a-desmethyl-5′-acetylatomaric acid (4), and the 10-keto-10-deisopropyliden-5′a-desmethyl-5′-acetylatomaric acid (5) together with the known compound the 10-keto-10-deisopropyliden-atomaric acid (6). The structures and relative stereochemistry of 3, 4 and 5 were elucidated by NMR and MS techniques. The observed chemical differences among populations of S. zonale can be related to its geographic distribution and can open an avenue to the discovery of new compounds in algae.

A morphological characterization of Padina boergesenii Allender & Kraft was carried out based on variation in sporophytes and gametophytes of male and female plants from Mexican populations from the Gulf of Mexico and Caribbean Sea. We analyzed 78 herbarium specimens from ENCB (47 vouchers), FEZA (30) and UAMIZ (1). The specimens were taken during 1960 to 2007 at 14 coastal and 20 insular localities from Veracruz, Campeche, Yucatan and Quintana Roo. Of the specimens examined 95% were sporophytic thalli; only 5% were gametophytic, two female and one male. The one thallus seen with both types of gametangia came from Isla Chica, Yucatan, suggesting that P. boergesenii can have monoecious or dioecious thalli. In coastal localities the thalli become shallowly split into fan-shaped segments, whereas in insular localities they are semicircular with entire margins and only rarely split into segments. Finally, this taxon, which inhabits the intertidal zone, is distributed in Mexico from Veracruz to Quintana Roo.

Se realizó la caracterización morfológica de Padina boergesenii Allender y Kraft para México, con base en el estudio de los talos esporofitos y gametofitos masculino y femenino, estos últimos se reconocen por primera vez en el litoral mexicano del Golfo de México y Mar Caribe. Se revisaron un total de 78 ejemplares, 47 del herbario ENCB, 30 del herbario FEZA y uno del UAMIZ. Los especímenes correspondieron a 14 localidades litorales y 20 insulares de Veracruz, Campeche, Yucatán y Quintana Roo, México, recolectados durante los años 1960 a 2007. Del total de ejemplares examinados, el 95% fueron esporofitos, el 5% gametofitos, dos femeninos y uno masculino, así como un talo con ambos tipos de gametangios de Isla Chica, Yucatán. Este último hallazgo sugiere que esta especie puede ser dioica o monoica. La morfología del talo de Padina boergesenii es variable, ya que en localidades litorales crece generalmente en la zona intermareal y las láminas tienden a ser divididas; mientras, que en localidades insulares también habita la zona intermareal y las láminas son enteras o poco divididas. Finalmente, este taxón se distribuye desde Veracruz hasta Quintana Roo, México.

An extensive bibliographic revision of the genus Dictyopteris (Dictyotales, Phaeophyceae) previously recorded in the Mexico's shores was realizated. We checked herbarium's specimens that are housed in different herbaria for getting the information on this genus. Also, some samples of Dictyopteris were carried out in sixty localities from Ensenada, Baja California to Bahia San Agustin, Oaxaca in the Pacific coast and from Ciudad Madero, Tamaulipas to Banco Chinchorro, Quintana Roo at Atlantic coast of Mexico from 1988 to 2003. Analysis of this information showed us that this genus contains eight species; moreover, D. delicatula J.V. Lamouroux and D. polypodioides (De Candolle) J.V. Lamouroux are distributed for both coasts at the Pacific and Atlantic shores of Mexico. Reproductive structures of Dictyopteris jamaicensis W. Taylor are described for first time and Dictyopteris jolyana Oliveira and Furtado is a new record from the Mexican Caribbean. Morphological descriptions, cytology, reproductive stage, drawings, keys for determination, specimen's examinated and distinctive characteristics of each taxon are included

Se llevó a cabo una extensa revisión bibliográfica y de ejemplares de herbario de las especies asignadas al género Dictyopteris (Dictyotales, Phaeophyceae) que han sido registradas para las costas de México, así como treinta campañas de recolección de material biológico de 1988 a 2003 en 60 localidades comprendidas desde Ensenada, Baja California a Bahía de San Agustín, Oaxaca en la costa del Pacífico y de Ciudad Madero, Tamaulipas hasta Banco Chinchorro, Quintana Roo, en la costa del Atlántico de México. Los resultados obtenidos indican que el género Dictyopteris se encuentra representado por ocho especies: D. delicatula J.V. Lamouroux y D. polypodioides (De Candolle) J.V. Lamouroux, se distribuyen en ambas costas de México. Se registran por primera vez estructuras reproductoras de Dictyopteris jamaicencis W. Taylor y se cita por primera vez a Dictyopteris jolyana Oliveira y Furtado, para las costas del Caribe de México. Cada especie se acompaña con datos sobre su morfología, citología, estado reproductivo, esquemas en cámara clara, claves dicotómicas para su determinación, ejemplares representativos examinados y características distintivas para cada taxa.