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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).

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

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.