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Acanthophora spicifera harbors a diverse array of secondary metabolites with therapeutic potential. The aim of this study is to isolate and characterize secondary metabolites from A. spicifera and then evaluate the antiproliferation, antibacterial, and biofilm prevention properties, followed by an analysis of molecular docking experiments. By employing chromatographic analysis and NMR spectroscopy, the isolated compounds were, the known flavonol, 8-hydroxyquercetagetin (1), three recognized steroids cholest-4-ene-3,6-dione (2), cholest-5-en-3β-ol (3), and 5α-cholestane-3,6-dione (4), and 2-bromohexadecanoic acid (5). These compounds exhibited antimicrobial effects against various Gram-negative and Gram-positive bacteria with inhibition zones ranging from 6.5 ± 0.2 to 17.2 ± 0.12 mm and 7.0 ± 0.4 to 15.3 ± 0.60 mm, respectively. Compounds 1 and 2 inhibited biofilm formation in P. aeruginosa and S. aureus. Compounds 1–4 demonstrated binding affinity values between −7.5 and −9.4 kcal/mol to protein 1A0G. These binding affinity values were akin to that of amoxicillin, implying that one potential antibacterial mechanism of action of these compounds may involve the inhibition of bacterial cell wall synthesis. All compounds showed no toxicity against Artemia salina and weak activity against Lymphoma and Lewis lung carcinoma cell lines with LD50 > 100 μg/mL.

Purification of the organic extract of Laurencia obtusa Lamouroux by column chromatography and preparative thin layer chromatography provided four new compounds: a eudesmane-type sesquiterpenoid [eudesma-4(15),11-diene-5,7-diol (1)], a cuparane-type sesquiterpenoid [10-hydroxycuparaldehyde (2)], and two nor-cuparanes [3-hydroxy-15-nor-cuparan-10β-ol (3) and 2-bromo-3-hydroxy-15-nor-cuparan-10β-ol (4)]. Structural identification was made possible by comparison of spectral data with those reported in the literature. Compounds 3 and 4 are significant as nor-cuparanes are rarely isolated from marine environment. 1 showed moderate anticandidal activity, whereas 2 exhibited reasonable antibacterial activity against multidrug-resistant bacteria (especially Gram-positive). All the compounds are nontoxic to Artemia salina.

Background and Objective: With regard to the uniqueness of the red algae of the genus Laurencia as the source of C15-acetogenins, along with the diversity of biological applications; the acetogenin content of the Red Sea Laurencia obtusa was investigated. Materials and Methods: Fractionation and purification of the CH2Cl2/MeOH extract were carried out by applying several chromatographic techniques, including column and preparative thin-layer chromatography; followed by a series of 1H nuclear magnetic resonance measurements to give rise of some interesting notes. Toxicity to Artemia salina was evaluated. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. Results: A new rare chloroallene-based C15 acetogenin, laurentusenin (1) along with a new furan ring containing C15 acetogenin, laurenfuresenin (2), were isolated from the red alga L. obtusa. Comparing 1D and 2D NMR, MS, ultraviolet and infrared radiation spectral data for the newly isolated compounds with the reported bromoallene containing acetogenins spectral data was played the crucial role for characterization of their chemical structures. 1 and 2 exhibited bare toxicity (LD50 >12 mM) in test organism, A. salina and induced apoptotic death confirmed by DNA fragmentation and microscopic investigations. Conclusion: The isolated metabolite 1 showed unusual substituted allene side chain, while 2 inserted furan ring as a new acetogenin nucleus. Both compounds may play a role in apoptosis induction and initiation and propagation of inflammatory responses. [ABSTRACT FROM AUTHOR]

Three previously undescribed compounds, maneonenes and isomaneonene derivatives; in addition to five known compounds, two cuparene, one chamigrene, and two cis -maneonenes were isolated from the Red Sea red alga Laurencia obtusa . The chemical structures of all unknown metabolites were characterized employing spectroscopic methods and then were further confirmed by single crystal X-ray analysis. Jeddahenyne A has C-5-C-12 etheric linkage and C-13-C-14 carbon-carbon double bond; Jeddahenyne B has in addition to the aforementioned etheric linkage a C-13 carbonyl function and absence of halogenation, unusual features for the maneonenes while 12-debromo-12-methoxy isomaneonene A shows unrecorded methoxylation at C-12. The apoptosis-inducing or inhibiting effect of both compounds on apoptosis of peripheral blood neutrophils was studied. [ABSTRACT FROM AUTHOR]

A new eudesmane sesquiterpenoid, eudesma-4(15),7-diene-5,11-diol (1) along with the known trinor-sesquiterene, teuhetenone (2), and aseco-eudesmane sesquiterpene, chabrolidione B (3), have been isolated from the Red Sea red algaLaurencia obtusa. The chemical structures were elucidated on the basis of extensive spectroscopic analysis. The antifungal and cytotoxic activities of the isolated metabolites were tested against several fungi, yeast and human mammary carcinoma cell line (MCF-7). Compounds1and3showed a much better activity [minimum inhibitory concentration (MIC): 2.9 μM] than that of amphotericin B (MIC: 4.6 μM). Interestingly, compound2, the least active antifungal compound, retained the high anticancer activity against MCF-7 (22 μM) in comparison with cisplatin (59 μM), which was determined by employing lactate dehydrogenase assay. Compounds1–3are recorded here for the first time from algal flora. The chemotaxonomic importance of the isolated metabolites was discussed. [ABSTRACT FROM PUBLISHER]

The unexploited red algae Acanthophora is intriguing since some species of which are invasive and pose a threat to their new ecosystem. The algae express potent effects due to possessing a diversity of metabolites. Additionally, their crude extracts were intensively investigated. This review is interested in discussing the effects of the extracts and chemical structures of the isolated bioactive metabolites of the genus Acanthophora. Several classes of metabolites as steroids, alkaloids, and flavonoids, were documented. Polysaccharides, their derivatives, and fatty acids were also discussed. The standard protocols detected broad classes of metabolites. Nevertheless, the description of tannins, saponin, and terpenoids was missing in the further fractionation and structure elucidation. The crude extracts and their fractions showed bioactivities, including anticancer, antimicrobial, antivirus, antioxidant, and anticoagulant. The reported studies were limited to some species of Acanthophora , it is considered an opening the gate to do exploration of the other species. • Acanthophora seaweeds are invasive to some ecosystems, yet they have many phytochemicals. • Secondary metabolites like flavonoids, alkaloids, and steroids are common amongst Acanthophora members. • Anticancer, antimicrobial, antivirus, antioxidant, and anticoagulant are bioactivities from genus Acanthophora. [ABSTRACT FROM AUTHOR]

Abstract: Three new laurene-type sesquiterpenes, 12-hydroxy isolaurene (1), 8,11-dihydro-12-hydroxy isolaurene (2) and isolauraldehyde (3) were isolated from the organic extract of the red alga Laurencia obtusa. The chemical structures of isolates were determined by interpretation of their spectral data 1D and 2D NMR, UV, IR and MS. The newly isolated compounds were tested for their antimicrobial and antitumor activities. Compounds (1–3) exhibited potent activity against the Gram-positive Bacillus subtilis and Staphylococcus aureus, where 3 proved to be the most active (MIC 35 and 27 μg/mL, respectively). Moreover, compound 3 exhibited a significant activity against Candida albicans (MIC of 70 μg/mL) and revealed to have very promising activity in an in vitro model of Ehrlich ascites Carcinoma. [Copyright &y& Elsevier]

A new C15 acetogenin, cyclic enyne (12 E)- cis-maneonene-E ( 1) and (12 Z)- trans-maneonene-B ( 2), together with different secondary metabolites including sesquiterpenoid 2,10-dibromo-3-chloro-α-chamigrene ( 3) and fatty acid aldehydes ( 4-8) were isolated from the petroleum ether extract of a red alga, identified as Laurencia papillosa, collected from the Saudi Red Sea coast. The L. papillosa crude extract and its active ingredient acetogenin ( 1) have been evaluated for the ability to control two main economically important pests, the confused flour beetle larvae Tribolium confusum and Culex pipiens mosquito larvae. Compound 1 showed high potential as a natural insecticide against these two pests. In the case of T. confusum larvae, the LD50 values were 0.21 and 0.16% after 6 and 12 days of treatment with crude extract and acetogenin, respectively. On the other hand, the resulting LC50 values of mosquito larvae bioassay were 30.7, 36.9, and 41.8 ppm after 24 h treatment against 2nd, 3rd, and 4th larval instars, respectively. Also, an increase of the insecticidal effects against mosquito larvae was recorded after extending treatment time to 48 h. [ABSTRACT FROM AUTHOR]

isolation, structure elucidation and cytotoxicity of three new sesquiterpene alcohols, laur-2-ene-3,12-diol (I), cuparene-3,12-diol (II), and 8,11-dihydro-1-methoxylaurokamuren-12-ol (III), along with the known diterpene, kahukuen-10-ol [ABSTRACT FROM AUTHOR]