1H NMR (600 MHz, D2O) δ 8.12 (s, 1H), 8.08 (s, 1H), 7.99 (s, 1H), 7.90 (s, 1H), 5.90 (d, J = 2.7 Hz, 1H), 5.79 (d, J = 3.5 Hz, 1H), 4.53 (dd, J = 5.2 Hz, J = 2.7 Hz, 1H), 4.52–4.48 (m, 1H), 4.38 (dd, J = 5.0 Hz, J = 3.6 Hz, 1H), 4.35–4.28 (m, 1H), 4.18–4.07 (m, 3H), 3.98 (td, J = 10.7 Hz, J = 2.6 Hz, 1H), 3.88–3.80 (m, 2H), 3.72 (dd, J = 12.9 Hz, J = 3.5 Hz, 1H), 3.16–2.98 (m, 3H), 2.88–2.76 (m, 2H), 2.62 (dt, J = 14.0 Hz, J = 2.7 Hz, 1H), 2.17–1.98 (m, 2H).