Oxygen Insertion of <i>o</i>-Quinone under Catalytic Hydrogenation Conditions
作者:Da-Li Zhang、Li-Yan Zhou、Jun-Min Quan、Wei Zhang、Lian-Quan Gu、Zhi-Shu Huang、Lin-Kun An
DOI:10.1021/ol400164e
日期:2013.3.15
An oxygen-insertion reaction that transforms an o-quinone and a conjugated alpha-diketone substrate Into an anhydride product or derivative under catalytic hydrogenation conditions is reported. The experiments and computations indicate that the oxygen insertion proceeds via a radical mechanism mediated by an acetoxyl radical.
Potent, Irreversible Inhibition of Human Carboxylesterases by Tanshinone Anhydrides Isolated from<i>Salvia miltiorrhiza</i>(“Danshen”)
作者:M. Jason Hatfield、Randall J. Binder、Rowan Gannon、Ellie M. Fratt、John Bowling、Philip M. Potter
DOI:10.1021/acs.jnatprod.8b00378
日期:2018.11.26
The roots of Salvia miltiorrhiza ("Danshen") have been used in Chinese herbal medicine for centuries for a host of different conditions. While the exact nature of the active components of this material are unknown, large amounts of tanshinones are present in extracts derived from these samples. Recently, the tanshinones have been demonstrated to be potent human carboxylesterase (CE) inhibitors, with the ability to modulate the biological activity of esterified drugs. During the course of these studies, we also identified more active, irreversible inhibitors of these enzymes. We have purified, identified, and synthesized these molecules and confirmed them to be the anhydride derivatives of the tanshinones. These compounds are exceptionally potent inhibitors (K-i < 1 nM) and can inactivate human CEs both in vitro and in cell culture systems and can modulate the metabolism of the esterified drug oseltamivir. Therefore, the coadministration of Danshen extracts with drugs that contain the ester chemotype should be minimized since, not only is transient inhibition of CEs observed with the tanshinones, but also prolonged irreversible inhibition arises via interaction with the anhydrides.
CHANG, HSON MOU;CHOANG, TAI FRANCIS;CHUI, KUK YING;HON, PO MING;LEE, CHI +, J. CHEM. RES. (S),(1990) N, C. 114-115
作者:CHANG, HSON MOU、CHOANG, TAI FRANCIS、CHUI, KUK YING、HON, PO MING、LEE, CHI +