Design and synthesis of HDAC inhibitors to enhance the therapeutic effect of diffuse large B-cell lymphoma by improving metabolic stability and pharmacokinetic characteristics.

Histone deacetylases (HDAC) are clinically validated and attractive epigenetic drug targets for human cancers. Several HDAC inhibitors have been approved for cancer treatment to date, however, clinical applications have been limited due to the poor pharmacokinetics, bioavailability, selectivity of the HDAC inhibitors and most of them need to be combined with other drugs to achieve better results. Here, we describe our efforts toward the discovery of a novel series of lactam-based derivatives as selective HDAC inhibitors. Intensive structural modifications lead to the identification of compound 24g as the most active Class I HDAC Inhibitor, along with satisfactory metabolic stability in vitro (t1/2, human = 797 min) and the desirable oral bioavailability (F = 92%). More importantly, compound 24g showed good antitumor efficacy in a TMD-8 xenograft model (TGI = 77%) without obvious toxicity. These results indicated that Class I HDAC Inhibitor could be potentially used to treat certain diffuse large B-cell lymphoma therapeutics.

[Effect of Tongfeng trace elements nutrient balance agent on growth, physiological characteristics and content of active constituents of Glycyrrhiza uralensis].

OBJECTIVE: To investigate the effects of Tongfeng trace elements nutrient balance agent on the various growth indicators, physiological indicators, and the contents of liquiritin and glycyrrhizic acid in one-year old Glycyrrhiza uralensis. METHOD: The plants of G. uralensis growing in Chifeng of Inner Mongolia and medicinal garden of Beijing University of Chinese Medicine were fertilized for two times, respectively. The photosynthetic physiological indicators were measured by LI-6400 photosynthetic instrument. The pigments and antioxidase activities of the leaves were determined. Then contents of liquiritin and glycyrrhizic acid in the plants were determined by HPLC. RESULT: The application of this trace element nutrient balance agent could significantly improve the height, chla and chlb, and the photosynthetic physiology indicator such as P(n), C(i), and G(s). Similarly, it could significantly increase the fresh weight of shoots and dry weight of the roots. Compared with control block (CK), the fertilizer which was diluted by 300 times (T(1)) and 600 times (T(2)) significantly increased the content of glycyrrhizic acid by 24.72% and 20. 23%. There was significant difference between different treatments (P < 0.05). CONCLUSION: The Tongfeng trace elements nutrient balance agent could promote growth, physiology and the content of active constituents of G. uralensis, especially the effect of T(1) was superior to T(2).