Secondary Metabolites with Anti-Inflammatory Activity from Laurencia majuscula Collected in the Red Sea

Morphological and Chemical Diversity within Japanese Laurencia Complex (Rhodomelaceae, Ceramiales, Rhodophyta)

Seaweeds of the red algal genus Laurencia are distributed worldwide in tropical, subtropical to temperate zones, growing in Japan from Hokkaido to Okinawa. Laurencia is highly difficult to classify morphologically because of a high degree of morphological variation within individual species. Nevertheless, Laurencia investigation is favored by organic chemists as it produces uniquely structured compounds. Halogenated secondary metabolites are considered to be used as chemical markers for chemical systematics (chemotaxonomy) of this troublesome genus. As a "weedy seaweed", Laurencia is not effectively utilized, yet it produces a variety of metabolites and thus, holds good potential for containing compounds with specific activity, especially in aspects of secondary metabolites. In this review, we reported significant morphological features to distinguish species in this genus, and the morphological features, habitat, distribution, and chemical composition that help discriminate Japanese Laurencia species.

A Survey of Recently Discovered Naturally Occurring Organohalogen Compounds

The discovery of naturally occurring organohalogen compounds has increased astronomically in the 55 years since they were first discovered─from fewer than 50 in 1968 to a combined 7,958 described examples in three comprehensive reviews. The present survey, which covers the period 2021-2023, brings the number of known natural organohalogens to approximately 8,400. The organization is according to species origin, and coverage includes marine and terrestrial plants, fungi, bacteria, marine sponges, corals, cyanobacteria, tunicates, and other marine organisms.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Rugulopteryx-Derived Spatane, Secospatane, Prenylcubebane and Prenylkelsoane Diterpenoids as Inhibitors of Nitric Oxide Production

This study aimed to evaluate the anti-inflammatory potential of the different classes of diterpenoids produced by algae of the genus Rugulopteryx. First, sixteen diterpenoids (1-16), including spatane, secospatane, prenylcubebane, and prenylkelsoane metabolites, were isolated from the extract of the alga Rugulopteryx okamurae collected at the southwestern Spanish coasts. Eight of the isolated diterpenoids are new compounds whose structures were determined by spectroscopic means: the spatanes okaspatols A-D (1-4); the secospatane rugukamural D (8); the prenylcubebanes okacubols A (13) and B (14); and okamurol A (16), which exhibits an unusual diterpenoid skeleton featuring a kelsoane-type tricyclic nucleus. Second, anti-inflammatory assays were performed on microglial cells Bv.2 and macrophage cells RAW 264.7. Compounds 1, 3, 6, 12, and 16 caused significant inhibition of the NO overproduction induced by LPS in Bv.2 cells, and compounds 3, 5, 12, 14, and 16 significantly decreased levels of NO in LPS-stimulated RAW 264.7 cells. The most active compound was okaspatol C (3), which completely suppressed the effects of LPS stimulation, both in Bv.2 and in RAW 264.7 cells.