Hus, the structure of compound 1 was established as a brand new kind
Hus, the structure of compound 1 was established as a new sort of macrolide, named moniristenulide, as shown in Figure 1.(a)(b)Figure 2. (a) 1H-1HH COSY) and crucial HMBC () ) correlations of moniristenulide (1); (b)ROESY Figure two. (a) 1 H-1 COSY ( (–) and essential HMBC ( correlations of moniristenulide (1); (b) ROESY correlation (dashed arrow) establishing N-Acetylneuraminic acid Technical Information relative configuration of 1. correlation (dashed arrow) establishing relative configuration of 1. Table 1. 1D and 2D NMR (500 MHz)was isolated as colorless crystal. Its HR-ESI-MS Jat m/z 299.0919 [M + H]+ Compound two data of moniristenulide (1) in DMSO-d6 ( in ppm, in Hz). Position 2 3ax 3eq four 5 6 7 eight 9 10 1 2 3 4a 4b 5a 5b six H four.58 brd (13.4) three.21 m two.40 m 5.95 d (two.0) 6.14 d (two.0) 5.75 d (15.six) 6.94 m 2.41 m 2.07 m two.01 m 1.81 m 3.54 msuggested a molecular formula of C17 H14 O5 .1 Its 1 H NMR spectrum showed resonances for C HMBC H-1H COSY ROESY 5 aromatic protons at H 7.33 (1H, dd, J = 1.7, 7.5 Hz), 7.20 (1H, ddd, J = 1.7, 7.four, 7.four Hz), 76.9 C-4, C-3 H-3ax, H-3eq, H-6 H-3eq, H-3, H-4b, H-6 six.89 (1H, overlap.), six.87 (1H, overlap.), 6.08 (1H, s), two signals of oxygenated methylene at C-4, C-6 H-2, H-3eq H-3eq, 6-OH 38.5 H five.81 and H five.76 (eachC-10 d, J = 1.five Hz), H-2, H-3ax two oxygenated methine protons at H 5.64 C-4, 1H, H-2, H-6, H-3ax (1H, dd, J = 2.eight, four.4 Hz) and five.25 (1H, dd, J = two.6, four.4 Hz), two signals of-diastereotopic 198.5 methylene protons at H- 2.27 (1H, dt, J = 2.8, 13.8 Hz) and 2.15 (1H, dt, J-= 2.eight, 13.8 Hz) 163.1 and97.3 methoxy singlet at H four.09 (3H, s). Analysis of 13 C NMR spectrum 1 combined with C-7, C-8, C-10 HSQC allowed for identifying the existence of 17-carbon atoms, like -12 sp2 carbons, 164.1 two94.7 methylene carbons atC-7, 26.5 and one hundred.eight, two methine carbons at C 67.five and 62.4, and C-4, C-6, C C-10 H-3, H-1 a single methoxy group at C- 60.1 (Table two). The COSY correlations of four aromatic protons 162.four at H 7.33, 7.20, six.89 and- 6.87 (H-3 -6 ) in addition to the respective HMBC correlations 103.4 confirmed a presence of disubstituted aromatic DBCO-PEG4-Maleimide Antibody-drug Conjugate/ADC Related B-ring, whilst the remaining sharp singlet 164.eight at H six.08 (H-8) described a C-4 H-3 120.2 C-1, C-3, standard penta-substituted aromatic A-ring. Furthermore, the H-3, H-4ab COSY experiment showed one more spin system from H-2 to H-4 andH-2, H-8, H-5CH-CH2 indicated a b 150.1 C-1, C-2, C-4, C-5 H-2, H-4ab H-3, H-4b CH sequence. Furthermore, the crucial HMBC correlation from H-6 (H 7.33) to C-2 (C 25.3 C-2, C-3 C-5, C-6 H-3, H-5b, H-4a 67.5) revealed the flavan (2-phenylchromane) skeleton (Figure 3). The HMBC correlation H-6, H-4a, their from methine H-4 C-2, C-3, C-4 C-2 (C 153.six) andH-5b chemical shift indicated their (H five.64) to 29.7 C-3, C-4, bridge. All these data deduced that compound two includes a 4-OH-6, H-5a linkage through an oxygen C-6 H-2, H-3eq, at , five.81 70.9 C-2 2 -cycloflavan as a partial structure. TheH-2, 6-OH, H-5ab doublet signals H-4bH6-OH and remaining two five.76 had a single bond correlation to a carbon atom at C one hundred.eight, which were assigned as a methylenedioxy group. These methylenedioxy doublet was connected to a flavan core by crucial HMBC correlations to C-6 and C-7. The location of methoxy group (H four.09) at C-5 was suggested by HMBC correlations. Around the basis of your above evidence, the planar structure of compound 2 was elucidated as 5-methoxy-6,7-methylenedioxy-4-O-2 -cycloflavan and regarded as as an unprecedented organic solution. This spectroscopic information of compound two is somewhat related towards the literature values fo.
