Anti-Angiogenic Properties of BDDPM, a Bromophenol from Marine Red Alga Rhodomela confervoides, with Multi Receptor Tyrosine Kinase Inhibition Effects

Anticancer Activities of Marine-Derived Phenolic Compounds and Their Derivatives

Since the middle of the last century, marine organisms have been identified as producers of chemically and biologically diverse secondary metabolites which have exerted various biological activities including anticancer, anti-inflammatory, antioxidant, antimicrobial, antifouling and others. This review primarily focuses on the marine phenolic compounds and their derivatives with potent anticancer activity, isolated and/or modified in the last decade. Reports on the elucidation of their structures as well as biosynthetic studies and total synthesis are also covered. Presented phenolic compounds inhibited cancer cells proliferation or migration, at sub-micromolar or nanomolar concentrations (lamellarins D (37), M (38), K (39), aspergiolide B (41), fradimycin B (62), makulavamine J (66), mayamycin (69), N-acetyl-N-demethylmayamycin (70) or norhierridin B (75)). In addition, they exhibited anticancer properties by a diverse biological mechanism including induction of apoptosis or inhibition of cell migration and invasive potential. Finally, phlorotannins 1–7 and bromophenols 12–29 represent the most researched phenolic compounds, of which the former are recognized as protective agents against UVB or gamma radiation-induced skin damages. Finally, phenolic metabolites were assorted into six main classes: phlorotannins, bromophenols, flavonoids, coumarins, terpenophenolics, quinones and hydroquinones. The derivatives that could not be attributed to any of the above-mentioned classes were grouped in a separate class named miscellaneous compounds.

Marine Bromophenol Bis(2,3,6-Tribromo-4,5-Dihydroxybenzyl)ether Inhibits Angiogenesis in Human Umbilical Vein Endothelial Cells and Reduces Vasculogenic Mimicry in Human Lung Cancer A549 Cells

Angiogenesis, including the growth of new capillary blood vessels from existing ones and the malignant tumors cells formed vasculogenic mimicry, is quite important for the tumor metastasis. Anti-angiogenesis is one of the significant therapies in tumor treatment, while the clinical angiogenesis inhibitors usually exhibit endothelial cells dysfunction and drug resistance. Bis(2,3,6-tribromo-4,5-dihydroxybenzyl)ether (BTDE), a marine algae-derived bromophenol compound, has shown various biological activities, however, its anti-angiogenesis function remains unknown. The present study illustrated that BTDE had anti-angiogenesis effect in vitro through inhibiting human umbilical vein endothelial cells migration, invasion, tube formation, and the activity of matrix metalloproteinases 9 (MMP9), and in vivo BTDE also blocked intersegmental vessel formation in zebrafish embryos. Moreover, BTDE inhibited the migration, invasion, and vasculogenic mimicry formation of lung cancer cell A549. All these results indicated that BTDE could be used as a potential candidate in anti-angiogenesis for the treatment of cancer.

New 3-Aryl-2-(2-thienyl)acrylonitriles with High Activity Against Hepatoma Cells

New 2-(thien-2-yl)-acrylonitriles with putative kinase inhibitory activity were prepared and tested for their antineoplastic efficacy in hepatoma models. Four out of the 14 derivatives were shown to inhibit hepatoma cell proliferation at (sub-)micromolar concentrations with IC50 values below that of the clinically relevant multikinase inhibitor sorafenib, which served as a reference. Colony formation assays as well as primary in vivo examinations of hepatoma tumors grown on the chorioallantoic membrane of fertilized chicken eggs (CAM assay) confirmed the excellent antineoplastic efficacy of the new derivatives. Their mode of action included an induction of apoptotic capsase-3 activity, while no contribution of unspecific cytotoxic effects was observed in LDH-release measurements. Kinase profiling of cancer relevant protein kinases identified the two 3-aryl-2-(thien-2-yl)acrylonitrile derivatives 1b and 1c as (multi-)kinase inhibitors with a preferential activity against the VEGFR-2 tyrosine kinase. Additional bioinformatic analysis of the VEGFR-2 binding modes by docking and molecular dynamics calculations supported the experimental findings and indicated that the hydroxy group of 1c might be crucial for its distinct inhibitory potency against VEGFR-2. Forthcoming studies will further unveil the underlying mode of action of the promising new derivatives as well as their suitability as an urgently needed novel approach in HCC treatment.

Progress of Bromophenols in Marine Algae from 2011 to 2020: Structure, Bioactivities, and Applications

Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antiradical, antimicrobial, anticancer, antidiabetic, anti-inflammatory effects, and so on. Here, we briefly review the recent progress of these marine algae biomaterials and their derivatives from 2011 to 2020, with respect to structure, bioactivities, and their potential application as pharmaceuticals.

A Systematic Review of Recently Reported Marine Derived Natural Product Kinase Inhibitors

Protein kinases are validated drug targets for a number of therapeutic areas, as kinase deregulation is known to play an essential role in many disease states. Many investigated protein kinase inhibitors are natural product small molecules or their derivatives. Many marine-derived natural products from various marine sources, such as bacteria and cyanobacteria, fungi, animals, algae, soft corals, sponges, etc. have been found to have potent kinase inhibitory activity, or desirable pharmacophores for further development. This review covers the new compounds reported from the beginning of 2014 through the middle of 2019 as having been isolated from marine organisms and having potential therapeutic applications due to kinase inhibitory and associated bioactivities. Moreover, some existing clinical drugs based on marine-derived natural product scaffolds are also discussed.

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

Isolation, finding or discovery of novel anticancer agents is very important for cancer treatment, and seaweeds are one of the largest producers of chemically active metabolites with valuable cytotoxic properties, and therefore can be used as new chemotherapeutic agents or source of inspiration to develop new ones. Identification of the more potent and selective anticancer components isolated from brown, green and red seaweeds, as well as studies of their mode of action is very attractive and constitute a small but relevant progress for pharmacological applications. Several researchers have carried out in vitro and in vivo studies in various cell lines and have disclosed the active metabolites among the terpenoids, including carotenoids, polyphenols and alkaloids that can be found in seaweeds. In this review the type of metabolites and their cytotoxic or antiproliferative effects will be discussed additionally their mode of action, structure-activity relationship and selectivity will also be revealed. The diterpene dictyolactone, the sterol cholest-5-en-3β,7α-diol and the halogenated monoterpene halomon are among the reported compounds, the ones that present sub-micromolar cytotoxicity. Additionally, one dimeric sesquiterpene of the cyclolaurane-type, three bromophenols and one halogenated monoterpene should be emphasized because they exhibit half maximal inhibitory concentration (IC₅₀) values between 1–5 µM against several cell lines.

From Marine Origin to Therapeutics: The Antitumor Potential of Marine Algae-Derived Compounds

Marine environment has demonstrated to be an interesting source of compounds with uncommon and unique chemical features on which the molecular modeling and chemical synthesis of new drugs can be based with greater efficacy and specificity for the therapeutics. Cancer is a growing public health threat, and despite the advances in biomedical research and technology, there is an urgent need for the development of new anticancer drugs. In this field, it is estimated that more than 60% of commercially available anticancer drugs are natural biomimetic inspired. Among the marine organisms, algae have revealed to be one of the major sources of new compounds of marine origin, including those exhibiting antitumor and cytotoxic potential. These compounds demonstrated ability to mediate specific inhibitory activities on a number of key cellular processes, including apoptosis pathways, angiogenesis, migration and invasion, in both in vitro and in vivo models, revealing their potential to be used as anticancer drugs. This review will focus on the bioactive molecules from algae with antitumor potential, from their origin to their potential uses, with special emphasis to the alga Sphaerococcus coronopifolius as a producer of cytotoxic compounds.

Molecular Targets of Active Anticancer Compounds Derived from Marine Sources

Over the past decades, a number of novel compounds, which are produced in the marine environment, have been found to exhibit the anticancer effects. This review focuses on molecular targets of marine-derived anticancer candidates in clinical and preclinical studies. They are kinases, transcription factors, histone deacetylase, the ubiquitin-proteasome system, and so on. Specific emphasis of this review paper is to provide information on the optimization of new target compounds for future research and development of anticancer drugs, based on the identification of structures of these target molecules and parallel compounds.

Marine natural products

Covering: 2015. Previous review: Nat. Prod. Rep., 2016, 33, 382-431This review covers the literature published in 2015 for marine natural products (MNPs), with 1220 citations (792 for the period January to December 2015) 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 (1340 in 429 papers for 2015), 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.