## 2 Results and Discussion  
Compound **1** was isolated as white crystals (mp, 122-123 \({}^{\circ}\)C) and its molecular formula C\({}_{27}\)H\({}_{42}\)O\({}_{4}\) was established on the basis of the (+)-HRESIMS \(m\)/\(z\) 431.3175 [M + H]\({}^{+}\) (calculated 431.3161), indicating seven degrees of unsaturation. The IR spectrum showed absorption bands for hydroxyl (3393 cm\({}^{-1}\)), conjugated ketone carbonyl (1645 cm\({}^{-1}\)), ester carbonyl (1728 cm\({}^{-1}\)), and olefin (1558, 1540 cm\({}^{-1}\)) groups. The \({}^{13}\)C NMR, DEPT and HSQC spectra (Table 1, Supplementary Figures S3 and S4) exhibited the signals of one conjugated ketone carbonyl (\(\delta\)c 194.7), one ester carbonyl (\(\delta\)c 171.0), two quaternary sp\({}^{2}\) (\(\delta\)c 147.7 and 191.1), one methine sp\({}^{2}\) (\(\delta\)c 99.9), one methylene sp\({}^{2}\) (\(\delta\)c 106.4), three quaternary sp\({}^{3}\) (\(\delta\)c 37.4, 37.8, 39.8), one oxymethine sp\({}^{3}\) (\(\delta\)c 80.8), three methine sp\({}^{3}\) (\(\delta\)c 55.4, 56.4 and 59.8), eight methylene sp\({}^{3}\) (\(\delta\)c 18.7, 19.6, 23.3, 23.6, 37.2, 38.0, 38.2 and 40.5) and six methyl (\(\delta\)c 15.3, 16.3, 16.4, 21.3, 24.9 and 28.0) carbons. The \({}^{1}\)H NMR spectrum (Table 1, Supplementary Figure S1) revealed the presence of one hydrogen-bonded hydroxyl group of an enol at \(\delta\)H 15.47, s, two exocyclic methylene protons at \(\delta\)H 4.84, brs and 4.50, brs, one olefinic proton at \(\delta\)H 5.45, s, and the protons of six methyl groups at \(\delta\)H 0.69, s, 0.83, s, 0.84, s, 0.86, s, 2.05, s (integrating for two methyls). Except for the enolic hydroxyl group, the olefinic proton and the conjugated ketone carbonyl (\(\delta\)c 194.7), the \({}^{1}\)H and \({}^{13}\)C data (Table 1, Supplementary Figures S1 and S3) revealed the presence of a perhydrophenanthrene moiety, similar to that of aszonapyrone A [6]. Like aszonapyrone A, the acetoxyl group on C-3 of compound **1** was \(\beta\), as was evidenced by the coupling constants of H-3 (\(\delta\)H 4.48, dd, \(J=10.9\), 4.6 Hz). Another portion of the molecule, which consists of C\({}_{6}\)H\({}_{9}\)O\({}_{2}\), was identified as (4Z)-5-hydroxy-3-oxohex-4-enyl group due to the HMBC correlations (Table 1, Supplementary Figure S5) of H\({}_{3}\)-20 (\(\delta\)H 2.05, s) to C-18 (\(\delta\)c 99.9) and C-19 (\(\delta\)c 191.1), of H-18 (\(\delta\)H 5.45, s) to C-16 (\(\delta\)c 37.2), C-17 (\(\delta\)c 194.7), C-19 (\(\delta\)c 191.1) and C-20 (\(\delta\)c 24.9), as well as the NOESY correlation (Supplementary Figure S6) between H-18 and H\({}_{3}\)-20. That C-15 of the (4Z)-5-hydroxy-3-oxohex-4-enyl group was connected to C-14 of the perhydrophenanthrene moiety was supported by the correlations between H-14 (\(\delta\)H 1.59, m) and H-15 (\(\delta\)H 1.86, m) in the COSY spectrum (Table 1, Supplementary Figure S2), as well as by the HMBC correlation of H\({}_{2}\)-15 to C-13 (\(\delta\)c 147.7). The structure and stereochemistry of compound **1** were unambiguously determined by X-ray analysis (Figure 2), and the absolute configurations of C-3, C-5, C-8, C-9, C-10 and C-14 were identified as 3\(S\), 5\(R\), 8\(R\), 9\(R\), 10\(R\) and 14\(S\), respectively. Since **1** is a new compound, we have named it sartorenl. The biosynthetic pathway of sartorenl (**1**) resembles those proposed for aszonapyrone A and sartorypyone A [6], which is hypothesized as originating from a reaction of the th Figure 3: Proposed biogenesis of sartorenol (**1**). Figure 2: Ortep view of sartorenol (**1**). Compound **2** was isolated as white solid (mp, 182-183 \({}^{\circ}\)C), and its molecular formula C\({}_{23}\)H\({}_{23}\)N\({}_{3}\)O\({}_{2}\) was established on the basis of the (+)-HRESIMS _m/z_ 374.1876 [M + H]\({}^{+}\) (calculated for C\({}_{23}\)H\({}_{24}\)N\({}_{3}\)O\({}_{2}\), 374.1869), indicating fourteen degrees of unsaturation.