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Marine products are among the most promising sources of biologically active molecules. Aplysinopsins, tryptophan-derived marine natural products, were isolated from different natural marine sources including sponges, stony corals (hard corals) especially genus scleractinian, as well as sea anemone, in addition to one nudibranch. Aplysinopsins were reported to be isolated from different marine organisms related to various geographic areas such as Pacific, Indonesia, Caribbean, and Mediterranean regions. This review gives an up-to-date overview of marine alkaloid aplysinopsins: their various sources, their synthesis, and the fact that many aplysinopsin derivatives are biologically active compounds. [ABSTRACT FROM AUTHOR]

Marine products are among the most promising sources of biologically active molecules. Aplysinopsins, tryptophan-derived marine natural products, were isolated from different natural marine sources including sponges, stony corals (hard corals) especially genus scleractinian, as well as sea anemone, in addition to one nudibranch. Aplysinopsins were reported to be isolated from different marine organisms related to various geographic areas such as Pacific, Indonesia, Caribbean, and Mediterranean regions. This review gives an up-to-date overview of marine alkaloid aplysinopsins: their various sources, their synthesis, and the fact that many aplysinopsin derivatives are biologically active compounds.

Objectives: The objective was to analyse the anti‐inflammatory potential of the invasive coral species Tubastraea coccinea and Tubastraea tagusensis. Methods: Methanolic extracts, fractions and synthesized compounds were evaluated for their anti‐inflammatory ability, and their composition was elucidated through chemical analysis. Key findings: The genus Tubastraea (Order Scleractinia, Family Dendrophylliidae) (known as sun corals) presents compounds with pharmacological value. The introduction of these azooxanthellate hard corals into Brazil, initially in Rio de Janeiro state, occurred through their fouling of oil and gas platforms from the Campos oil Basin. The two invasive species have successfully expanded along the Brazilian coast and threaten endemic species and biodiversity. The HPLC‐MS and GC‐MS data suggest the presence of aplysinopsin analogues (alkaloids). Anti‐inflammatory activity was observed in all samples tested in in‐vivo assays, especially in T. coccinea. The ethyl acetate fraction from this sample was more effective in in‐vitro assays for anti‐inflammatory activity. Depending on the concentration, this fraction showed cytotoxic responses. Conclusions: These species have potential pharmacological use, and considering their invasive nature, this study presents a potential alternative use, which may enhance the management of this biological invasion. [ABSTRACT FROM AUTHOR]

Abstract: Biosynthetic considerations inspired us to harness the templating properties offered by DNA to promote a [2+2] photoinduced cycloaddition. The method was developed based on the dimerization of (E)‐aplysinopsin, which was previously shown to be unproductive in solution. In sharp contrast, exposure of this tryptophan‐derived olefin to light in the presence of salmon testes DNA (st‐DNA) reproducibly afforded the corresponding homo‐dimerized spiro‐fused cyclobutane in excellent yields. DNA provides unique templating interactions enabling a singular mimic of the solid‐state aggregation necessary for the [2+2] photocycloaddition to occur. This method was ultimately used to promote the prerequisite dimerizations leading to both dictazole B and tubastrindole B, thus constituting the first example of a DNA‐mediated transformation to be applied to the total synthesis of a natural product. [ABSTRACT FROM AUTHOR]

• Aplysinopsin is a multi-targeted anti-Alzheimer lead compound. • First-generation aplysinopsin analogs were synthesized. • Sulphonamide derivative of aplysinopsin displays multi-targeted effect. • Aplysinopsin and new analogs shows BBB permeability. • Identified leads inhibits amyloid-β aggregation. Aplysinopsins are a group of marine-derived indole alkaloids that display diverse array of pharmacological effects. However, their effect on anti-Alzheimer targets has not been reported. Herein, we report the synthesis of aplysinopsin (1) and its effect on cholinesterases and beta-site amyloid-precursor protein cleaving enzyme 1 (BACE-1). It inhibits electric eel acetylcholinesterase (AChE), equine serum butyrylcholinesterase (BChE), and human BACE-1 with IC 50 values of 33.9, 30.3, and 33.7 µM, respectively, and excellent BBB permeability (P e 8.92 × 10−6 cm/s). To optimize its sub-micromolar activity, the first-generation analogs were prepared and screened. Two most active analogs 5b and (Z)- 8g were found to effectively permeate the BBB (P e > 5 × 10−6 cm/s). The N -sulphonamide derivative 5b display better cholinesterase inhibition, whereas the other analog (Z)- 8g strongly inhibits BACE-1 (IC 50 0.78 µM) activity. The analog 5b interacts primarily with PAS of AChE, and thus exhibit a mixed-type of inhibition. In addition, aplysinopsin along with new analogs inhibited the self-induced Aβ 1-42 aggregation. The data presented herein indicate that the aplysinopsin-scaffold holds a potential for further investigation as a multi-targeted anti-Alzheimer agent. [ABSTRACT FROM AUTHOR]