Compound 48/80 Technical Information Esulting in the oxidation of 1, a sample of 1 was analyzed by
Esulting from the oxidation of 1, a sample of 1 was analyzed by LC-HRESIMS more than time. Just after 36 h at area temperature, the 1:two Tasisulam medchemexpress region ratio changed from 70:30 to 7:93, as a result confirming the spontaneous conversion of your original unstable compound 1 into 2 (SI, Figure S4a). In parallel, another sample of 1 was monitored by 1 H-NMR, and its proton signals were observed to alter gradually via time till a practically complete conversion into 2 right after 48 h (SI, Figure S4b). Thinking of the instability of 1 as well as the feasibility of structural characterization of 2, we allowed 1 to be readily oxidized (DMSO, room temperature for 48 h) after which repurified by semi-preparative HPLC to yield two as an orange, amorphous powder (SI, Figure S5). The molecular formula C35 H42 N2 O14 S was confirmed for 2 based on its HRESIMS(+)-TOF spectrum, displaying [M + H]+ and [M + 2H]2+ ions at m/z 747.2434 ( -0.60 ppm) and m/z 374.1258 ( -1.60 ppm), respectively (SI, Figure S6). Additionally, tandem-mass spectrometry of your [M + H]+ adduct showed a single fragment ion at m/z 142.1239, which was consistent together with the presence on the monosaccharide forosamine and as a result advanced the partial glycosidic nature of two (SI, Figure S7). The planar structure of two (Figure 1) was determined by 1D and 2D NMR spectroscopic analyses (Table two). Interpretation of 13 C NMR and HSQC spectra (SI, Figures S12 and S13) revealed the presence of 13 quaternary carbons, like six carbonyl groups (among them, two quinone CO signals at C 186.three and 181.3 ppm), one particular oxygenated aromatic carbon (C 160.eight) and two characteristic hetero atom-substituted carbons at C 95.6 and 81.9 ppm. The remaining signals were three aromatic/olefinic methines, 6 oxygenated methines (including one particular anomeric carbon at C 93.7), 3 aliphatic methines (such as a characteristic -proton of amino acid at C 51.5), 5 methylenes and six methyl groups. Amongst the latter, two singlet methyls were assigned to an N,N-dimethyl group depending on their chemical equivalence in 1 H NMR (H two.54) and 13 C NMR chemical shift (C 40.4 ppm).Molecules 2021, 26, 6580 Molecules 2021, 26,four of 24 4 ofFigure Figure 1. Structure of 22(4-AcCys-FGA). A-E rings of with the -lactone-pyranonaphtoquinone core Structure of (4-AcCys-FGA). A rings the -lactone-pyranonaphtoquinone core are indicated. are indicated. Table two. 1H NMR (500 MHz in DMSO-d6) and 13C NMR (125 MHz, DMSO-d6) data for 1. Table 2. 1 H NMR (500 MHz in DMSO-d6) and 13 C NMR (125 MHz, DMSO-d6) data for 1.Position No. Position No. 1 1 three 4 3 4a four 5 4a 5a five six 5a 7 six eight 7 9 eight 9-OH 9a 9 10 9-OH 10a 9a 11 ten 12 10a three 11 four 12 4-OCOCH3 three 4-OCOCH3 five 4 46 -OCOCH3 47 -OCOCH3 1 2C, Mult C , Mult 95.six, C 95.6, C 69.8, CH 69.eight, CH 81.9, C 81.9, C 141.two, C 141.two, C 181.3, C 131.4, C 181.3, C 118.9, CH 131.4, C 137.4, CH 118.9, CH 125.3, CH 137.four, CH 160.8, C125.three, CH 160.eight, C 114.9, C 186.three, C 114.9, C 140.2, C 34.4, CH2 186.3, C 174.1, C 140.2, C 70.9, CH 34.four, CH two 65.1 a, CH 174.1, C 169.9, C 70.9, CH 20.eight, CH3 65.1 a , CH 35.five, CH2 169.9, C 62.8, CH 20.2, CH3 20.eight, CH3 93,7, CH 28.7, CH2 14.H (Mult, J in Hz) 4.74, d (5.0)H (Mult , J in Hz) four.74, d (five.0)7.60, dd (7.4, 1.5) 7.82, dd 7.60, dd (7.4, 1.five) (8.six, 7.four) 7.43, dd (8.six, 1.5)7.82, dd (8.6, 7.four) 7.43, dd (8.6, 1.5)11.72, br s11.72, br s3.61, dd (18.1, five.0)/2.59, d (18.1)three.61, dd (18.1, five.0)/2.59, d (18.1) 4.78 a , d (four.two)four.78 a, d (four.2) 5.49, q (three.three)two.01, s 5.49, q (3.three) H-5eq:1.89, m/H-5ax: 1.84, m four.22, m 2.01, 1.18, d (six.three) s a, br s 4.76 1.53, m; 1.40, m 1.61, m.