scholarly journals Hemimycalins C–E; Cytotoxic and Antimicrobial Alkaloids with Hydantoin and 2-Iminoimidazolidin-4-one Backbones from the Red Sea Marine Sponge Hemimycale sp.

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 691
Author(s):  
Lamiaa A. Shaala ◽  
Diaa T. A. Youssef

In the course of our continuing efforts to identify bioactive secondary metabolites from Red Sea marine sponges, we have investigated the sponge Hemimycale sp. The cytotoxic fraction of the organic extract of the sponge afforded three new compounds, hemimycalins C–E (1–3). Their structural assignments were obtained via analyses of their one- and two-dimensional NMR spectra and HRESI mass spectrometry. Hemimycalin C was found to differ from the reported hydantoin compounds in the configuration of the olefinic moiety at C-5–C-6, while hemimycalins D and E were found to contain an 2-iminoimidazolidin-4-one moiety instead of the hydantoin moiety in previously reported compounds from the sponge. Hemimycalins C–E showed significant antimicrobial activity against Escherichia coli and Candida albicans and cytotoxic effects against colorectal carcinoma (HCT 116) and the triple-negative breast cancer (MDA-MB-231) cells.

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 371 ◽  
Author(s):  
Francisco Ortiz-López ◽  
Elsa Alcalde ◽  
Aida Sarmiento-Vizcaíno ◽  
Caridad Díaz ◽  
Bastien Cautain ◽  
...  

Fractionation of the bioactive extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-157 led to the isolation of the known 3-hydroxyquinaldic acid (4), its amide (5) and three new derivatives (1–3) containing different amino acid residues. The structures of the new molecules (1–3), including their absolute configuration, were determined by the analysis of their ESI-TOF MS and one-dimensional (1D) and two-dimensional (2D) NMR spectra and advanced Marfey’s analysis of their hydrolyzation products. Compound 3 spontaneously dimerized in solution to give the disulfide derivative 6. Unfortunately, none of the new compounds isolated confirmed the antimicrobial activity found in the bacterial extract, perhaps indicating that such antibacterial activity might be due to presence in the extract at the trace level of larger bioactive 3-hydroxyquinaldic acid derivatives from which compounds 1–3 are biosynthetic precursors. Cytotoxicity tests confirmed the moderate and weak IC50 values of 15.6 and 51.5 µM for compounds 5 and 1, respectively.


Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 525
Author(s):  
Lamiaa A. Shaala ◽  
Diaa T. A. Youssef

During an investigation of the chemistry of the Red Sea Verongiid sponge Pseudoceratina arabica, we discovered a small molecule, pseudoceratonic acid (1), along with the new moloka’iamine derivatives, ceratinines N (2), O (3), and the previously reported compounds moloka’iamine (4), hydroxymoloka’iamine (5) and ceratinamine (6). The structural assignments of 1–6 were accomplished by interpretation of their NMR and HRESIMS spectral data. Pseudoceratonic acid possesses a dibrominated hydrazine-derived functional group not found in any reported chemical compound. Pseudoceratonic acid selectively inhibited the growth of E. coli and S. aureus, while ceratinine N selectively inhibited C. albicans. Further, ceratinine N showed potent cytotoxic effects against the triple-negative breast cancer, colorectal carcinoma, and human cervical carcinoma cell lines down to 2.1 µM.


2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Elsa Anselmi ◽  
Mohamed Abarbri ◽  
Alain Duchêne ◽  
Sandrine Lamandé-Langle ◽  
Jérôme Thibonnet

1,2,4-Trisubstituted pyrroles were synthesized with an original one-pot domino allylic amination/palladium-catalysed Sonogashira cross-coupling and heterocyclisation process.1H and13C NMR spectra were assigned for twelve new compounds containing different substituents in positions 1 and 2, and a carboxylic acid or ester group in position 4. Each assignment was based on the combination of one, and two-dimensional experiments (APT, COSY, HMBC).


Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 38
Author(s):  
Chi-Jen Tai ◽  
Chiung-Yao Huang ◽  
Atallah F. Ahmed ◽  
Raha S. Orfali ◽  
Walied M. Alarif ◽  
...  

Chemical investigation of a Red Sea Spongia sp. led to the isolation of four new compounds, i.e., 17-dehydroxysponalactone (1), a carboxylic acid, spongiafuranic acid A (2), one hydroxamic acid, spongiafuranohydroxamic acid A (3), and a furanyl trinorsesterpenoid 16-epi-irciformonin G (4), along with three known metabolites (−)-sponalisolide B (5), 18-nor- 3,17-dihydroxy-spongia-3,13(16),14-trien-2-one (6), and cholesta-7-ene-3β,5α-diol-6-one (7). The biosynthetic pathway for the molecular skeleton of 1 and related compounds was postulated for the first time. Anti-inflammatory activity of these metabolites to inhibit superoxide anion generation and elastase release in N-formyl-methionyl-leucyl phenylalanine/cytochalasin B (fMLF/CB)-induced human neutrophil cells and cytotoxicity of these compounds toward three cancer cell lines and one human dermal fibroblast cell line were assayed. Compound 1 was found to significantly reduce the superoxide anion generation and elastase release at a concentration of 10 μM, and compound 5 was also found to display strong inhibitory activity against superoxide anion generation at the same concentration. Due to the noncytotoxic activity and the potent inhibitory effect toward the superoxide anion generation and elastase release, 1 and 5 can be considered to be promising anti-inflammatory agents.


1979 ◽  
Vol 57 (14) ◽  
pp. 1901-1902 ◽  
Author(s):  
Maurice Jay ◽  
Jean Favre-Bonvin ◽  
Eckhard Wollenweber

The structures 4′,5-dihydroxy-2′,3,7,8-tetramethoxyflavone and 5-hydroxy-2′,3,4′,7,8-penta-methoxyflavone have been attributed to two new compounds isolated from a farinose exudate of Notholaenaaffinis; this result is derived from uv, ms, and nmr spectra of the natural products and their derivatives.


2014 ◽  
Vol 37 (3) ◽  
pp. 928-935 ◽  
Author(s):  
Ahmed Abdel-Lateff ◽  
Walied M. Alarif ◽  
Hany Z. Asfour ◽  
Seif-Eldin N. Ayyad ◽  
Alaa Khedr ◽  
...  

1981 ◽  
Vol 36 (5) ◽  
pp. 571-577 ◽  
Author(s):  
Jochen Ellermann ◽  
Leo Mader ◽  
Kurt Geibel

H2 reacts with [Ir{(Ph2P)2N-p-C6H4CH3}2]Cl · 3 C6H6 (1) to give cis-[Ir(H)2{(Ph2P)2N-p-C6H4CH3}2]Cl · CH2Cl2 (2a). By reaction of 2a with NaBPh4 cis-[Ir(H)2{(Ph2P)2N-p-C6H4CH3}2]BPh4 (2 b) is obtained. Refluxing of 2a in CH2Cl2 yields trans-[lr(H)2{(Ph2P)2N-p-C6H4CH3}2]Cl · 1/2 CH2Cl2 (3a), which undegoes metatheses with NaBPh4 to trans-[Ir(H)2{(Ph2P)2N-p-C6H4CH3}2]BPh4 (3b). 3a is also formed by refluxing of 1 in methanol in the presence of oxygen. Oxidative addition of HCl to 1 and reaction with NaBPh4 yields trans-[Ir(H)(Cl){(Ph2P)2N-p-C6H4CH3}2]BPh4 (4b). The new compounds are characterised by their IR, Raman, 31P{1H} PFT and 1H NMR Spectra


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