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Neste trabalho, foi planejada a síntese de lipídeos resorcinólicos análogos as citosporonas utilizando métodos clássicos de síntese orgânica. O objetivo principal foi à preparação dos compostos: ácido 2,4-dihidróxi-6-octil-benzóico (6) e 2,4-diidróxi-6-(8-oxooctil)-benzóico (7). Foram estudadas rotas de síntese visando à produção desses compostos, foi possível obtenção de três intermediários avançados, com sucesso: 2,4 dimetóxi-6-octil-benzoato de etila (8), 2-hidróxi-4-metóxi-6-octil-benzoato de etila (9) e ácido 2-hidróxi-4-metóxi-6-octil-benzóico (10), os quais tiveram suas estruturas determinadas por técnicas de espectroscopia de RMN de 1H e de 13C, e no caso de (10) incluindo técnicas bidimensionais (HSQC e HMBC).

Abstract Cytosporones, a class of octaketide resorcinolic lipids, have drawn the attention of researchers for exhibiting a number of notable biological properties. Herein, we describe routes to synthesize the bioactive synthetic resorcinolic lipids AMS35AA and AMS35BB with excellent overall yields using 3,5-dimethoxybenzoic acid as the starting material. The methods proved remarkably efficient to achieve the target compounds and comprise the synthesis of AMS35AA catalyzed by ascorbic acid (vitamin C).

Resorcinolic lipids, a class of bioactive amphiphilic molecules found widely in nature, hold potential for a variety of biological and industrial applications. This report describes the synthesis of three bioactive structural analogues of resorcinolic lipids, obtained by subjecting ethyl (E)-2-undecenoate and ethyl acetoacetate to a Michael reaction in the presence of sodium ethoxide to generate a Michael adduct, followed by cyclization in the reaction medium. Ethyl 2-octyl-4,6-dioxocyclohexanecarboxylate (7) was thus produced with a 60% yield. To perform an aromatization step, 7 was subsequently treated with I2 in methanol under reflux, producing a combined 80% yield of 2,4-dimethoxy-6-octyl-ethyl benzoate (1) and 2-hydroxy-4-methoxy-6-octyl-ethyl benzoate (2) at a 7:3 ratio, respectively. 2-Hydroxy-4-methoxy-6-octyl-benzoic acid was obtained with a 60% yield by treating 1 with BBr3/CHCl3. The structures of the synthesized compounds and intermediates were elucidated by 1H and 13C NMR spectroscopy, employing two-dimensional techniques (HSQC and HMBC). DOI: http://dx.doi.org/10.17807/orbital.v12i2.237

Resorcinolic lipids, a class of bioactive amphiphilic molecules found widely in nature, hold potential for a variety of biological and industrial applications. This report describes the synthesis of three bioactive structural analogues of resorcinolic lipids, obtained by subjecting ethyl (E)-2-undecenoate and ethyl acetoacetate to a Michael reaction in the presence of sodium ethoxide to generate a Michael adduct, followed by cyclization in the reaction medium. Ethyl 2-octyl-4,6-dioxocyclohexanecarboxylate (7) was thus produced with a 60% yield. To perform an aromatization step, 7 was subsequently treated with I2 in methanol under reflux, producing a combined 80% yield of 2,4-dimethoxy-6-octyl-ethyl benzoate (1) and 2-hydroxy-4-methoxy-6-octyl-ethyl benzoate (2) at a 7:3 ratio, respectively. 2-Hydroxy-4-methoxy-6-octyl-benzoic acid was obtained with a 60% yield by treating 1 with BBr3/CHCl3. The structures of the synthesized compounds and intermediates were elucidated by 1H and 13C NMR spectroscopy, employing two-dimensional techniques (HSQC and HMBC). [ABSTRACT FROM AUTHOR]

Influenza A virus (IAV) is a severe worldwide threat to public health and economic development due to its high morbidity and mortality. Marine-derived fungi have been evidenced as a prolific source for the discovery of pharmacologically-active lead compounds. During the course of our search for novel bioactive substances from marine microorganisms, six new polyketides, including two octaketides (1–2), one chromone derivative (13), two highly substituted phthalides (17–18), and one α-pyrone derivative (21) along with 22 known congeners were isolated from a mangrove-associated fungus Diaporthe sp. SCSIO 41011. Their structures were determined by spectroscopic analysis and by comparison with literature data. And the absolute configurations were established according to the specific rotation or electron circular dichroism method. Antiviral evaluation results revealed that compounds 14, 15, 26, and 5-chloroisorotiorin displayed significant anti-IAV activities against three influenza A virus subtypes, including A/Puerto Rico/8/34 H274Y (H1N1), A/FM-1/1/47 (H1N1), and A/Aichi/2/68 (H3N2), with IC50 values in the range of 2.52–39.97 μM. The preliminary structure-activity relationships (SARs) are also discussed. These findings expand the chemical and bioactive diversity of polyketides derived from the genus Diaporthe, and also provide a basis for further development and utilization of chromone, xanthone, and chloroazaphilone derivatives as source of potential anti-viral chemotherapy agents.

In screening endophytic fungi from Costa Rica for bioactivity, fungal culture CR200, isolated from a buttonwood tree, was found to contain compounds that initiate DNA damage in a test strain of E. coli (Biochemical Induction Assay, BIA) and inhibit growth of Gram-positive bacteria, including antibiotic-resistant strains. Two new bisanthraquinones (cytoskyrins A and B) and five new related octaketides (cytosporones A-E) were isolated from fermentation broths of this fungus. Cytoskyrin A exhibited potent in-vitro antibacterial (MICs against Gram-positive bacteria, 0.03 - 0.25 μg/mL) and DNA-damaging activities (10 ng/spot), whereas cytoskyrin B was inactive in these assays. Among the cytosporones, only D and E exhibited Gram-positive activity, but they were inactive in the BIA. Mechanistically, cytoskyrin A specifically inhibited DNA synthesis in E. coli imp at its MIC; however, it also moderately inhibited protein synthesis at 2x its MIC. Cytoskyrin A exhibited poor cytotoxicity against tumor cell lines (IC50 > 5 μg/mL) compared to known antitumor agents. The nuclear ribosomal internal transcribed spacer region of CR200 was found to share highest similarity (94-96%) with Cytospora spp. Micro- and macroscopic morphological observations of the conidia and conidiomata, respectively, also suggested this fungus to be a Cytospora sp.

Abstract: Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded 11 new compounds including cytosporones J–N (1–3, 5–6), five new coumarins pestalasins A–E (8–12), and a new alkaloid named pestalotiopsoid A (14), along with the known compounds cytosporone C (4), dothiorelone B (7), and 3-hydroxymethyl-6,8-dimethoxycoumarin (13). The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis. [Copyright &y& Elsevier]

Abstract: Cytosporones O, P and Q, together with the known compounds cytosporones B, C, D, E and dothiorelones A, B, C, and H were isolated from the ascomycete fungus Cytospora sp. during a chemotaxonomic study of fungal endophytes belonging to the related genera Cytospora and Phomopsis from Brazil. The structures were determined by NMR spectroscopy and mass spectrometry. With exception of cytosporones D, E, Q, and dothiorelone B, all compounds were consistently detected in the metabolite profiles of eight Cytospora isolates investigated; and were also produced by a distinct chemotype of Phomopsis. [Copyright &y& Elsevier]

Influenza A virus (IAV) is a severe worldwide threat to public health and economic development due to its high morbidity and mortality. Marine-derived fungi have been evidenced as a prolific source for the discovery of pharmacologically-active lead compounds. During the course of our search for novel bioactive substances from marine microorganisms, six new polyketides, including two octaketides ( 1-2 ), one chromone derivative ( 13 ), two highly substituted phthalides ( 17-18 ), and one α-pyrone derivative ( 21 ) along with 22 known congeners were isolated from a mangrove-associated fungus Diaporthe sp. SCSIO 41011. Their structures were determined by spectroscopic analysis and by comparison with literature data. And the absolute configurations were established according to the specific rotation or electron circular dichroism method. Antiviral evaluation results revealed that compounds 14 , 15 , 26 , and 5-chloroisorotiorin displayed significant anti-IAV activities against three influenza A virus subtypes, including A/Puerto Rico/8/34 H274Y (H1N1), A/FM-1/1/47 (H1N1), and A/Aichi/2/68 (H3N2), with IC 50 values in the range of 2.52-39.97 μM. The preliminary structure-activity relationships (SARs) are also discussed. These findings expand the chemical and bioactive diversity of polyketides derived from the genus Diaporthe , and also provide a basis for further development and utilization of chromone, xanthone, and chloroazaphilone derivatives as source of potential anti-viral chemotherapy agents.

In screening endophytic fungi from Costa Rica for bioactivity, fungal culture CR200, isolated from a buttonwood tree, was found to contain compounds that initiate DNA damage in a test strain of E. coli (Biochemical Induction Assay, BIA) and inhibit growth of Gram-positive bacteria, including antibiotic-resistant strains. Two new bisanthraquinones (cytoskyrins A and B) and five new related octaketides (cytosporones A-E) were isolated from fermentation broths of this fungus. Cytoskyrin A exhibited potent in-vitro antibacterial (MICs against Gram-positive bacteria, 0.03-0.25 microg/mL) and DNA-damaging activities (10 ng/spot), whereas cytoskyrin B was inactive in these assays. Among the cytosporones, only D and E exhibited Gram-positive activity, but they were inactive in the BIA. Mechanistically, cytoskyrin A specifically inhibited DNA synthesis in E. coli imp at its MIC; however, it also moderately inhibited protein synthesis at 2x its MIC. Cytoskyrin A exhibited poor cytotoxicity against tumor cell lines (IC50>5 microg/mL) compared to known antitumor agents. The nuclear ribosomal internal transcribed spacer region of CR200 was found to share highest similarity (94-96%) with Cytospora spp. Micro- and macroscopic morphological observations of the conidia and conidiomata, respectively, also suggested this fungus to be a Cytospora sp.