Table 1 NMR spectroscopic data of spirornatas A-C a Spirornata ASpirornata BSpirornata CC.13Cδ 1H NMR (mult., JCOSYHMBCC.13Cδ 1H NMR (mult.,COSYHMBCC.13Cδ 1H NMR (mult.,COSYHMBCN.in Hz, int)bN.J in Hz, int)bN.J in Hz, int)b262.14.02 (Ha) (1H, d, JH-2aC-7261.64.05 (Ha) (1H, d,–C-2a, 8262.44.09 (Ha) (1H, d,–C-2a, 8= 9.65)J = 8.65)J = 7.86)3.83 (Hb) (1H, d, J3.37 (Hb) (1H, d,3.48 (Hb) (1H, d,= 8.85)J = 8.55)J = 7.68)2a42.62.82 (1H, t, J =–C-3, 5a2a127.9–––2a127.9–––7.99)3179.2–––347.22.90 (2H, s)–C-2a, 4348.12.96 (2H, s)C-2a, 4570.44.38 (Ha) (1H, d, JH-5aC-34203.5–––4202.4–––= 8.65)4.12 (Hb) (1H, d, J= 8.56)5a35.22.32 (1H, t, J =H-6C-5539.72.48 (2H, dd, J =H-6C-4, 6a540.82.46 (2H, dd, J =H-6C-4, 6a7.99)10.19, 4.86)10.34, 4.76)637.72.18 (1H, m)H-8C-5a, 7622.52.27 (2H, dd, J =–C-4, 6a625.52.24 (2H, dd, J =–C-4, 6a10.09, 4.66)10.33, 4.96)7101.4–––6a125.7–––6a124.7–––814.21.02 (3H, d, J =–C-6772.55.53 (1H, s)–C-6a, 8,741.12.36 (Ha) (1H, d,–C-6a, 87.22)9J = 4.65)2.07 (Hb) (1H, d,J = 5.15)3 ʹ41.22.42 (1H, m)H-4 ʹC-7, 1 a,898.6–––897.8–––2 a4 ʹ27.71.67 (1H, m)C-5 ʹ9170.9–––3 ʹ41.72.99 (1H, d, J =H-4 ʹC-8, 1 a7.46)5 ʹ43.11.52 (Ha) (1H, dd, JH-6 ʹC-6 ʹ1021.22.23 (3H, s)–C-94 ʹ71.45.42 (1H, dt,H-5 ʹC-5 ʹ, 8 ʹ= 10.09, 4.96)5.22, 7.44)1.46 (Hb) (1H, dd, J= 10.09, 4.66)6 ʹ68.53.75 (1H, m)H-7 ʹC-73 ʹ35.62.37 (1H, m)H-4 ʹC-8, 1 a,5 ʹ35.61.92 (Ha) (1H, m)H-6 ʹC-6 ʹ2 a1.65 (Hb) (1H, m)7 ʹ22.81.11 (3H, d, J =–C-6 ʹ4 ʹ23.41.72 (Ha) (1H, m)H-5 ʹC-3 ʹ6 ʹ68.23.75 (1H, m)H-7 ʹC-85.45)1.38 (Hb) (1H, m)8 ʹ19.30.96 (3H, d, J =–C-4 ʹ5 ʹ29.51.51 (Ha) (1H, m)H-6 ʹ–7 ʹ21.91.20 (3H, d, J =–C-6 ʹ6.79)1.45 (Hb) (1H, m)6.64)1 a33.42.27 (Ha) (1H, d, J–C-2 a6 ʹ68.03.68 (1H, m)H-7 ʹC-8, 5 ʹ8 ʹ170.8–––= 5.85)2.10 (Hb) (1H, d, J= 5.66)2 a175.6–––7 ʹ19.11.11 (3H, d, J =–9 ʹ21.22.21 (3H, s)–C-8 ʹ7.65)3 a64.24.17 (2H, t, J =H-4 aC-2 a1 a36.72.30 (Ha) (1H, d,–C-2 a1 a132.4–––8.76)J = 6.33)2.08 (Hb) (1H, d,J = 6.15)4a30.02.24 (2H, q, J =H-5aC-5a2a174.1–––2a125.15.33 (1H, t, J =H-3aC-1a,6.92)8.65)3 a5 a120.65.20 (1H, t, J =–C-3 a, 6 a3 a64.54.64 (2H, d, J =H-4 aC-2 a, 4 a3 a28.11.99 (2H, m)–C-4 a7.05)7.25)6 a131.7–––4 a129.55.37 (1H, q, J =–5 a4 a27.42.01 (2H, m)H-5 a–6.75)7 a24.81.76 (3H, s)–6a5a135.15.28 (1H, q, J =H-6a–5a123.55.23 (1H, t, J =–C-4a,7.05)6.82)6 a8 a17.91.79 (3H, s)–6 a6 a25.52.01 (2H, m)H-7 a5 a6 a130.2–––7 a14.31.02 (3H, d, J =–6 a7 a24.61.84 (3H, s)–6 a8.65)8 a18.61.74 (3H, s)–6a9a19.01.81 (3H, s)–1a CN: Carbon number in the structures. a NMR spectra recorded using Bruker AVANCE III 500 MHz (AV 500) spectrometer (Bruker, Karlsruhe, Germany) in deuteriated chloroform (CDCl) as aprotic 3 solvent at ambient temperature with tetramethyl silane (TMS) as the internal standard (δ 0 ppm). NMR data was administered using MestReNova-7.1.1–9649. 1 H NMR spectra were recorded at 500 MHz, while the 13 C NMR spectra were recorded at 125 MHz.

Published as part of Chakraborty, Kajal & Dhara, Shubhajit, 2022, Spirornatas A-C from brown alga Turbinaria ornata: Anti-hypertensive spiroketals attenuate angiotensin-I converting enzyme, pp. 3 in Phytochemistry (113024) 195 on page 3, DOI: 10.1016/j.phytochem.2021.113024, http://zenodo.org/record/8194471