New Hygrocins K-U and Streptophenylpropanamide A and Bioactive Compounds from the Marine-Associated <i>Streptomyces</i> sp. ZZ1956

• Main Authors: Wenwen Yi (Author), Asif Wares Newaz (Author), Kuo Yong (Author), Mingzhu Ma (Author), Xiao-Yuan Lian (Author), Zhizhen Zhang (Author)
• Format: Book
• Published: MDPI AG, 2022-10-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics11111455; 2079-6382
• Keywords: marine <i>Streptomyces</i> sp. ZZ1956; Streptomycetaceae; hygrocins K-U; streptophenylpropanamide A; structure elucidation; antiglioma activity; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 11, Iss 11, p 1455 (2022)

Marine-derived <i>Streptomyces</i> actinomycetes are one of the most important sources for the discovery of novel bioactive natural products. This study characterized the isolation, structural elucidation and biological activity evaluation of thirty compounds, including twelve previously undescribed compounds, namely hygrocins K-U (<b>5</b>-<b>13</b>, <b>17</b> and <b>18</b>) and streptophenylpropanamide A (<b>23</b>), from the marine-associated actinomycete <i>Streptomyces</i> sp. ZZ1956. Structures of the isolated compounds were determined by a combination of extensive NMR spectroscopic analyses, HRESIMS data, the Mosher's method, ECD calculations, single crystal X-ray diffraction and comparison with reported data. Hygrocins C (<b>1</b>), D (<b>2</b>), F (<b>4</b>), N (<b>8</b>), Q (<b>11</b>) and R (<b>12</b>), 2-acetamide-6-hydroxy-7-methyl-1,4-naphthoquinone (<b>22</b>), echoside C (<b>27</b>), echoside A (<b>28</b>) and 11,11'-<i>O</i>-dimethylelaiophylin (<b>30</b>) had antiproliferative activity (IC₅₀: 0.16-19.39 μM) against both human glioma U87MG and U251 cells with hygrocin C as the strongest active compound (IC₅₀: 0.16 and 0.35 μM, respectively). The analysis of the structure-activity relationship indicated that a small change in the structures of the naphthalenic ansamycins had significant influence on their antiglioma activities. Hygrocins N (<b>8</b>), O (<b>9</b>), R (<b>12</b>), T (<b>17</b>) and U (<b>18</b>), 2-amino-6-hydroxy-7-methyl-1,4-naphthoquinone (<b>21</b>), 2-acetamide-6-hydroxy-7-methyl-1,4-naphthoquinone (<b>22</b>), 3'-methoxy(1,1',4',1"-terphenyl)-2',6'-diol (<b>26</b>), echoside C (<b>27</b>) and echoside A (<b>28</b>) showed antibacterial activity against methicillin-resistant <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> with MIC values of 3-48 μg/mL.