Cytotoxic effects of three new metabolites from Red Sea marine sponge, Petrosia sp

Diverse alkaloids from the aerial parts of Aconitum carmichaelii and antiproliferative activity of costemline via inhibiting SIRT1/ROCK1/P-STAT3 pathways

Six undescribed alkaloids together with 15 known alkaloids were isolated from the aerial parts of Aconitum carmichaelii. Their structures were elucidated extensively by NMR and HRESIMS spectroscopy. The absolute configurations of N-formyllaurotetanine, and the known compounds glaucine-β-N-oxide and glaucine-α-N-oxide were established by electronic circular dichroism (ECD) spectra. Notably, it was the discovery of rare indole alkaloids from the genus Aconitum, and biosynthetic pathway of compounds 1 and 6 was deduced. Evaluation of the antiproliferative activity of these alkaloids demonstrated that costemline exhibited significant anti-proliferation effects against HCT116, SKOV3, and A549 cells with IC₅₀ values of 5.6, 14.2, and 6.8 μM, respectively. Costemline could also inhibit the cell invasion activity of HCT116 cells. Mechanistic studies in HCT116 cells suggested that the antiproliferative activity of costemline was attributable to SIRT1/ROCK1/P-STAT3 pathways regulation. This study revealed the potential for developing and utilizing the aerial parts of Aconitum carmichaelii.

Secondary Metabolites from the Marine Sponges of the Genus Petrosia: A Literature Review of 43 Years of Research

Sponges are prolific sources of various natural products that have provided the chemical scaffolds for new drugs. The sponges of the genus Petrosia inhabit various regions and contain a variety of biologically active natural products such as polyacetylenes, sterols, meroterpenoids, and alkaloids. This review aims to provide a comprehensive summary of the chemical structures and biological activities of Petrosia metabolites covering a period of more than four decades (between 1978 and 2020). It is also described in this review that the major groups of metabolites from members of the genus Petrosia differed with latitude. The polyacetylenes were identified to be the most predominant metabolites in Petrosia sponges in temperate regions, while tropical Petrosia species were sources of a greater variety of metabolites, such as meroterpenoids, sterols, polyacetylenes, and alkaloids.

Medicinal Purposes: Bioactive Metabolites from Marine-derived Organisms

The environment of marine occupies about 95% biosphere of the world and it can be a critical source of bioactive compounds for humans to be explored. Special environment such as high salt, high pressure, low temperature, low nutrition and no light, etc. has made the production of bioactive substances different from terrestrial organisms. Natural ingredients secreted by marine-derived bacteria, fungi, actinomycetes, Cyanobacteria and other organisms have been separated as active pharmacophore. A number of evidences have demonstrated that bioactive ingredients isolated from marine organisms can be other means to discover novel medicines, since enormous natural compounds from marine environment were specified to be anticancer, antibacterial, antifungal, antitumor, cytotoxic, cytostatic, anti-inflammatory, antiviral agents, etc. Although considerable progress is being made within the field of chemical synthesis and engineering biosynthesis of bioactive compounds, marine environment still remains the richest and the most diverse sources for new drugs. This paper reviewed the natural compounds discovered recently from metabolites of marine organisms, which possess distinct chemical structures that may form the basis for the synthesis of new drugs to combat resistant pathogens of human life. With developing sciences and technologies, marine-derived bioactive compounds are still being found, showing the hope of solving the problems of human survival and sustainable development of resources and environment.

Marine Alkylpurines: A Promising Group of Bioactive Marine Natural Products

Marine secondary metabolites with a purine motif in their structure are presented in this review. The alkylpurines are grouped according to the size of the alkyl substituents and their location on the purine ring. Aspects related to the marine source, chemical structure and biological properties are considered together with synthetic approaches towards the natural products and bioactive analogues. This review contributes to studies of structure–activity relationships for these metabolites and highlights the potential of the sea as a source of new lead compounds in diverse therapeutic fields.

Marine Envenomation

Venomous aquatic animals are hazardous to swimmers, surfers, divers, and fishermen. Exposures include mild stings, bites, abrasions, and lacerations. Severe envenomations can be life threatening. This article reviews common marine envenomations, exploring causative species, clinical presentation, and current treatment recommendations. Recommendations are included for cnidaria, sponges, bristle worms, crown-of-thorns starfish, sea urchins, venomous fish, stingrays, cone snails, stonefish, blue-ringed octopus, and sea snakes. Immediate and long-term treatment options and management of common sequelae are reviewed. Antivenom administration, treatment of anaphylaxis, and surgical indications are discussed.

Cytotoxic scalarane-type sesterterpenes from the Saudi Red Sea sponge Hyrtios erectus

The CHCl3/MeOH extract of the marine sponge Hyrtios erectus showed cytotoxicity against three cancer cell lines HepG2, A549, and PC-3 with IC50 0.055, 0.044, and 0.023 μg/ml, respectively. The CH2Cl2 soluble fraction afforded three scalarane sesterterpenes (1-3) along with a cholestane derivative (4) and an indole alkaloid (5). Chemical structures were established by spectroscopic techniques and comparison with data reported in the literature. Scalarinol (1) was found as a new metabolite, while heteronemin (2) and 12-O-deacetyl-19-deoxyscalarin (3) are known compounds. 1-3 exhibited cytotoxic activity against the cancer cell lines with IC50 values ranging from 14 to 230 μM. The molecular affinity to the DNA was employed as marker to examine the proposed mechanism of cytotoxic activities. Compound 2, with IC50 28 μg/ml, displayed the highest affinity to the DNA.

Marine natural products

This review covers the literature published in 2014 for marine natural products (MNPs), with 1116 citations (753 for the period January to December 2014) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1378 in 456 papers for 2014), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

Steroidal constituents from the edible sea urchin Diadema savignyi Michelin induce apoptosis in human cancer cells

Bioassay-directed fractionation and purification were used to isolate 12 steroids (1-12) from a CH(2)Cl(2) extract of the edible Vietnamese sea urchin Diadema savignyi Michelin. The cytotoxic activity of the CH(2)Cl(2) extract and 12 steroids was evaluated in three human cancer cell lines (HL-60, PC-3, and SNU-C5). Relative to the effects of the positive control, mitoxantrone, the CH(2)Cl(2) extract (with an inhibitory concentration of 50% [IC(50)] values ranging from 1.37±0.15 to 3.11±0.15 μg/mL) and compounds 2 (with IC(50) values ranging from 5.29±0.11 to 6.80±0.67 μM) and 11 (with IC(50) values ranging from 4.95±0.07 to 6.99±0.28 μM) exhibited potent cytotoxic effects against all three tested human cancer cell lines. In addition, the CH(2)Cl(2) extract and compounds 2 and 11 were found to induce apoptosis. The induction of apoptosis was accompanied by alterations of the apoptosis-related protein expression, inactivation of ERK1/2 mitogen-activated protein kinase signaling, and decreased c-Myc expression. These data suggest that compounds 2 and 11 from the edible sea urchin D. savignyi may have potential for the treatment of colon cancer, leukemia, and prostate cancer as complementary cancer remedies.

Molecular architecture and biomedical leads of terpenes from red sea marine invertebrates

Marine invertebrates including sponges, soft coral, tunicates, mollusks and bryozoan have proved to be a prolific source of bioactive natural products. Among marine-derived metabolites, terpenoids have provided a vast array of molecular architectures. These isoprenoid-derived metabolites also exhibit highly specialized biological activities ranging from nerve regeneration to blood-sugar regulation. As a result, intense research activity has been devoted to characterizing invertebrate terpenes from both a chemical and biological standpoint. This review focuses on the chemistry and biology of terpene metabolites isolated from the Red Sea ecosystem, a unique marine biome with one of the highest levels of biodiversity and specifically rich in invertebrate species.