20β-羟基泼尼松龙的结构与绝对构型，泼尼松龙经海洋内生真菌石生青霉生物转化的产物。

Sultan Sadia, Noor Muhammad Zaimi Bin Mohd, Anouar El Hassane, Shah Syed Adnan Ali, Salim Fatimah, Rahim Rohani, Al Trabolsy Zuhra Bashir Khalifa, Weber Jean-Frédéric Faizal

Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia.

Atta-ur-Rahman Institute for Natural Products Discovery (AuRIns), Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia.

Molecules. 2014 Sep 3;19(9):13775-87. doi: 10.3390/molecules190913775.

The anti-inflammatory drug predinisolone (1) was reduced to 20β-hydroxyprednisolone (2) by the marine endophytic fungus Penicilium lapidosum isolated from an alga. The structural elucidation of 2 was achieved by 1D- and 2D-NMR, MS, IR data. Although, 2 is a known compound previously obtained through microbial transformation, the data provided failed to prove the C20 stereochemistry. To solve this issue, DFT and TD-DFT calculations have been carried out at the B3LYP/6-31+G (d,p) level of theory in gas and solvent phase. The absolute configuration of C20 was eventually assigned by combining experimental and calculated electronic circular dichroism spectra and 3JHH chemical coupling constants.

抗炎药物泼尼松龙（1）被从一种藻类中分离出的海洋内生真菌石生青霉还原为20β-羟基泼尼松龙（2）。通过一维和二维核磁共振、质谱、红外光谱数据对2进行了结构解析。尽管2是一种先前通过微生物转化获得的已知化合物，但所提供的数据未能证明C20的立体化学结构。为了解决这个问题，在气相和溶剂相中，于B3LYP/6-31+G(d,p)理论水平上进行了密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算。最终通过结合实验和计算得到的电子圆二色光谱以及3JHH化学耦合常数确定了C20的绝对构型。