We previously isolated valiolamine, a potent α-glucosidase inhibitor, from the fermentation broth of Streptomyces hygroscopicus subsp. limoneus (a producer of validamycins). This prompted us to search for new validamycins containing valiolamine. In this paper, we report the isolation, structure determination, and biological properties of two new components: validoxylamine G and its β-D-glucoside, validamycin G. Crude validamycins (1.2 kg) were chromatographed on a Dowex 1-X2 (OH⁻ form) column and further purified via Dowex 50W-X8 and rechromatography to obtain homogeneous validoxylamine G (2.2 g) and validamycin G (0.1 g). Structural analyses—including elemental analysis, ¹³C/¹H NMR spectrometry, acid hydrolysis (yielding D-glucose and validoxylamine G from validamycin G), hydrogenolysis (degrading validoxylamine G into validatol and valiolamine), and acetylation (affording octaacetate and undecaacetate)—revealed validoxylamine G consists of valiolamine and valienamine (or 1-epi-valienamine), and validamycin G is a mono-D-glucoside of validoxylamine G. The structure of validoxylamine G was elucidated as [(1S)-(1,4,6/5)-4,5,6-trihydroxy-3-hydroxymethyl-2-cyclohexenyl]-[(1S)-(1,2,4,5(OH)/3,5)-2,3,4,5-tetrahydroxy-5-(hydroxymethyl)cyclohexyl]amine.