*3.4. Identified of Secondary Metabolites from Strain NEAU-H2T*

Only major components were identified from the liquid fermentation extract. Compound **1** was obtained as white amorphous powder, and its molecular formula, C12H13NO3, was determined by high resolution electrospray ionization mass spectrometry (HRESIMS) data (m/z 242.0792 [M + Na]+, calculatedd for 242.0788), corresponding to 7 degrees of unsaturation (Figure S5). The 1H NMR showed the presence of five aromatic protons with signals at δ<sup>H</sup> 8.29 (s, 1H), 8.27 (d, *J* = 7.3 Hz, 1H), 7.46 (d, *J* = 7.4 Hz, 1H), 7.24 (td, *J* = 7.2, 1.2 Hz, 1H), and 7.21 (td, *J* = 7.2, 1.2 Hz, 1H), which indicated

a three-substituted indole moiety (Table 2, Figure S5). The 13C NMR and HSQC spectra revealed 12 carbons, which were classified into one methyl (δ<sup>C</sup> 17.9), five sp2 methines (δ<sup>C</sup> 135.8, 124.5, 123.4, 122.9, 112.9), three sp<sup>2</sup> quaternary carbons (δ<sup>C</sup> 138.2, 127.3, 116.3), and two oxygenated tertiary carbons (δ<sup>C</sup> 79.7 and 71.1) and a carbonyl carbon (δ<sup>C</sup> 197.2) (Figure S5).


**Table 2.** 1H (600 MHz) and 13C (150 MHz) NMR Data of **1** in CD3OD.

\* δC or H: chemical shift; *J:* coupling constant; COSY: correlated spectroscopy; HMBC: 1H detected heteronuclear multiple bond correlation.

The 1H-1H COSY and HSQC spectra of **1** showed two spin-coupling systems, H-9/H-10/H-11 and H-4/H-5/H-6/H-7 (Figure 5B). The HMBC cross-peaks from H-5 to C-3a, from H-6 to C-7a, and from H-2 to C-3/3a/C-7a further revealed the presence of an indole moiety. Cross-peaks from H-9 to C-8 and from H-10 to C-8 were observed in the HMBC spectrum, which suggested a 2,3-dihydroxybutanone connected with indole moiety at C-3 (Figure 5B). Therefore, the planar structure **1** was elucidated as depicted in Figure 5A.

**Figure 5.** (**A**)The structure of compounds **1**–**4**; (**B**) 2D NMR correlations of **1**.

Compound **2** was isolated as a colorless powder, HRESIMS m/z 235.0532 [M + Na]+(calculated for C9H12N2O2S, 235.0512); 1H NMR data (600 MHz) δ<sup>H</sup> 7.03 (1H, dd, *J* = 2.4, 1.4 Hz, H-7), 6.96 (1H, dd, *J* = 3.9, 1.3 Hz, H-9), 6.20 (1H, dd, *J* = 3.8, 2.5 Hz, H-8), 3.13 (2H, t, *J* = 6.7 Hz, H-4), 3.38 (2H, t, *J* = 6.7 Hz, H-3), 1.92 (3H, s, H-1); 13C NMR data (150 MHz, CD3OD) δ<sup>C</sup> 181.9 (C-5), 173.5 (C-2), 131.2 (C-6), 125.7 (C-7), 116.4 (C-9), 111.1 (C-8), 40.7 (C-3), 28.2 (C-4), and 22.5 (C-1) (Figure S6). Compound **2** was proven to be 3-Acetylamino-N-2-thienyl-propanamide by direct comparison of these data with those from the literature [56].

Compound **3**: 1H NMR data (600 MHz, DMSO-*d*6) δ<sup>H</sup> 8.37 (1H, s, H-8), 8.21 (1H, s, H-2), 5.90 (1H, d, *J* = 5.9 Hz, H-1 ), 4.55 (2H, t, *J* = 5.4 Hz, H-2 ), 4.14 (1H, m, H-3 ), 3.95 (1H, q, *J* = 3.3 Hz, H-4 ), 3.67 (1H, dd, *J* = 12.1, 3.5 Hz, H-5 ), 3.55 (1H, dd, *J* = 12.1, 3.5 Hz, H-5 ); 13C NMR data (150 MHz, DMSO-*d*6) δ<sup>C</sup> 154.3 (C-6), 151.7 (C-2), 149.9 (C-4), 138.6 (C-8), 119.8 (C-5), 87.8 (C-1 ), 85.8 (C-4 ), 73.6 (C-2 ), 70.5 (C-3 ), and 61.6 (C-5 ) (Figure S7). Compound **3** was proven to be *ß*-adenosine by direct comparison of these data with those from the literature [57].

Compound **4**: 1H NMR data (400 MHz, CD3OD) δ<sup>H</sup> 6.94 (1H, s, H-4), 6.85 (1H, d, *J* = 2.7 Hz, H-2), 6.18 (1H, m, H-3); 13C NMR (100 MHz, CD3OD) δC164.6 (C-6), 124.4 (C-2), 124.1 (C-5), 116.6 (C-4), and 110.6 (C-3) (Figure S8). Compound **4** was proven to be 2-minaline by direct comparison of these data with those from the literature [58].
