From Natural Xanthones to Synthetic C-1 Aminated 3,4-Dioxygenated Xanthones as Optimized Antifouling Agents

Biofouling, which occurs when certain marine species attach and accumulate in artificial submerged structures, represents a serious economic and environmental issue worldwide. The discovery of new non-toxic and eco-friendly antifouling systems to control or prevent biofouling is, therefore, a practical and urgent need. In this work, the antifouling activity of a series of 24 xanthones, with chemical similarities to natural products, was exploited. Nine (1, 2, 4, 6, 8, 16, 19, 21, and 23) of the tested xanthones presented highly significant anti-settlement responses at 50 μM against the settlement of mussel Mytilus galloprovincialis larvae and low toxicity to this macrofouling species. Xanthones 21 and 23 emerged as the most effective larval settlement inhibitors (EC₅₀ = 7.28 and 3.57 µM, respectively). Additionally, xanthone 23 exhibited a therapeutic ratio (LC₅₀/EC₅₀) > 15, as required by the US Navy program attesting its suitability as natural antifouling agents. From the nine tested xanthones, none of the compounds were found to significantly inhibit the growth of the marine biofilm-forming bacterial strains tested. Xanthones 4, 6, 8, 16, 19, 21, and 23 were found to be non-toxic to the marine non-target species Artemia salina (<10% mortality at 50 μM). Insights on the antifouling mode of action of the hit xanthones 21 and 23 suggest that these two compounds affected similar molecular targets and cellular processes in mussel larvae, including that related to mussel adhesion capacity. This work exposes for the first time the relevance of C-1 aminated xanthones with a 3,4-dioxygenated pattern of substitution as new non-toxic products to prevent marine biofouling.     

Marine-Derived Xanthone from 2010 to 2021: Isolation,Bioactivities and Total Synthesis

Marine life has proved to be an invaluable source of new compounds with significant bioactivities, such as xanthones. This review summarizes the advances made in the study of marine-derived xanthones from 2010 to 2021, from isolation towards synthesis, highlighting their biological activities. Most of these compounds were isolated from marine-derived fungi, found in marine sediments, and associated with other aquatic organisms (sponge and jellyfish). Once isolated, xanthones have been assessed for different bioactivities, such as antibacterial, antifungal, and cytotoxic properties. In the latter case, promising results have been demonstrated. Considering the significant bioactivities showed by xanthones, efforts have been made to synthesize these compounds, like yicathins B and C and the secalonic acid D, through total synthesis.     

Mono- and Dimeric Xanthones with Anti-Glioma and Anti-Inflammatory Activities from the Ascidian-Derived Fungus Diaporthe sp. SYSU-MS4722

Seven new xanthones, diaporthones A−G (1−7), together with 13 known analogues, including five mono- (8−14) and six dimeric xanthones (15−20), were obtained from the ascidian-derived fungus Diaporthe sp. SYSU-MS4722. Their planar structures were established by extensive spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HR-ESIMS). The absolute configurations of 1−7 were clearly identified by X-ray crystallographic analysis and calculation of the ECD Spectra. Compounds 15−20 showed significant anti-inflammatory activity with IC₅₀ values between 6.3 and 8.0 μM. In addition, dimeric xanthones (15−20) showed selective cytotoxicity against T98G cell lines with IC₅₀ values ranging from 19.5 to 78.0 μM.     

西南远志中[口山]酮类化合物的分离与鉴定

从西南远志的乙醇提取液中分离得到5个[口山]酮类化合物,利用理化常数和波谱解析的方法鉴定结构,分别确定为：1,5-二甲氧基-2,6-二羟基[口山]酮;1,2,8-三甲氧基-3,6-二羟基[口山]酮;1,3,8-三羟基-2,6-二甲氧基[口山]酮;1,2,3-三甲氧基-6,8-二羟基[口山]酮和1,3,6,8-四羟基-2,7-二甲氧基[口山]酮。     

西南远志5个口山酮类化合物

从西南远志乙醇提取液中分离得到5个黄酮类化合物,通过现代波谱学方法分别鉴定为：1,7,二甲氧基-2,3-二羟基（口山）酮;1,2,3-三甲氧基-7-羟基（口山）酮;1,3,6-三羟基-2,7-二甲氧基（口山）酮;1,2,7-三甲氧基-3-羟基（口山）酮;1,2,3,7-四甲氧基（口山）酮。     

扁蕾不同部位的化学成分研究

利用高效液相色谱-光电二极管阵列检测(HPLC-DAD)和高效液相色谱-电喷雾离子化-多级质谱联用技术(HPLC-ESI-MSn)定性定量分析了大兴安岭地区产传统蒙药扁蕾不同部位的化学成分,共检出11种化合物,其中9种化合物首次从扁蕾中检测到。研究结果表明,口山酮类化合物总含量在扁蕾各部位中的分布状态为:花>叶>侧枝>主茎>根。文章还研究了扁蕾口山酮类化学成分的组成信息,为阐明其最佳药用部位提供客观可靠的依据。     

Two new prenylated xanthones and a new prenylated tetrahydroxanthone from the pericarp of Garcinia mangostana

Two new prenylated xanthones and a new prenylated tetrahydroxanthone, garcimangosxanthone A–C (1–3), along with fourteen known xanthones were isolated from the pericarp of Garcinia mangostana. Their structures were elucidated on the basis of spectroscopic data. Compounds 1 and 2 exhibited in vitro cytotoxicity against A549, LAC and A375 cell lines with IC₅₀ values of 5.7–24.9 μM, which were comparable to those of doxorubicin.