*2.3. Identification of Compounds 1 or 2 by HRESIMS*

The authentic identification of compounds **1** and **2** into the three promising strains such as CB1-14, CB2-11, and CB2-6 (see Table 1) was carried out after isolation of these compounds by HPLC followed by analysis with HRESIMS. The strains were incubated at 200 rpm in 100 mL of modified MN liquid medium at 28 ◦C for 7 days. After incubation, the whole cultures were centrifuged to harvest the bacterial cells. Then cells were suspended in water (30 ml), frozen, and subjected to ultrasonic treatment. The suspension was extracted with EtOAc, and the organic phase was evaporated to dryness. The resulting mixture was dissolved in a small amount of EtOH, and extracts were subjected to HPLC on ODS-A columns. The fractions with retention times of 12 to 17 min were collected and analyzed by HRESIMS. Compounds showing ion peak with *m*/*z* 212.1757 [M + H]<sup>+</sup> (calcd for C11H22N3O, 212.1757) were isolated from strains CB1-14 and CB2-11. Strain CB1-14 showed a more intense peak at *m*/*z* 212.1757 compared with that for CB2-11. Their mass spectra were identical to the spectra of standards. As a result, monanchorins were identified in these two strains. However, in order to determine which of two epimeric compounds was biosynthesized by these microorganisms, it was necessary to isolate the alkaloids in amounts sufficient for the obtaining of NMR data.
