This study reports the isolation of one new C-methyl-flavone (6,8-dimethyl-4′,5-dihydroxy-3′,7-dimethoxyflavone, 1), along with one C-methyl-flavone (sideroxylin, 2), one known C-methyl-flavonol (quercetin, 3), two C-methyl-flavonol glycosides [(quercitrin, 4) and (guaijaverin, 5)], one lignan (9′,9′-O-feruloyl-(−)-seco-isolaricinresinol, 6) and gallic acid (7) from Myrcia guianensis (Aubl.) DC. The structural elucidation of compounds 1–7 was performed based on the detailed analysis of their NMR spectra and the comparison with the literature. This is the first report of compound 2 in the genus Myrcia and of compounds 3, 4, and 5 in M. guianensis, whereas compound 6 has not been isolated from any species of the Myrtaceae family. C-methyl-flavonoids are frequently isolated from Myrtaceae species; thus, the occurrence of C-methyl-flavones and C-methyl-flavonols in M. guianensis may present chemophenetics relevance to the consolidation of the genus Myrcia within the Myrtaceae family.

本研究报告了一种新的 C-甲基黄酮（6,8-二甲基-4',5-二羟基-3',7-二甲氧基黄酮，1）以及一种C-甲基黄酮（铁木精，2）的分离，一种已知的 C-甲基黄酮醇（槲皮素，3），两种 C-甲基黄酮醇糖苷 [（槲皮苷，4）和（愈创木苷，5）]，一种木脂素（9'，9'-O-阿魏酰-（- )-seco-isolaricinresinol, 6 ) 和没食子酸 ( 7 ) 来自Myrcia guianensis (Aubl.) DC。化合物1-7的结构解析是基于对其 NMR 光谱的详细分析和与文献的比较进行的。这是化合物2的首次报道在Myrcia属中，化合物3、4和5在M. guianensis中，而化合物6尚未从桃金娘科的任何物种中分离出来。C-甲基类黄酮经常从桃金娘科植物中分离出来；因此，C-甲基-黄酮和 C-甲基-黄酮醇在M. guianensis中的出现可能呈现出与桃金娘科Myrcia属的巩固相关的化学现象学。