2-(Isopropylamino)thieno[3,2-d]pyrimidin-4(3H)-one derivatives as selective phosphodiesterase 7 inhibitors with potent in vivo efficacy.

A new series of thienopyrimidinones is synthesized and evaluated as selective phosphodiesterase 7 (PDE7) inhibitors for the treatment of inflammatory diseases. The modification of the substituents on thienopyrimidinone revealed that an isopropylamino group at the 2-position was favorable for aqueous solubility. The introduction of 3-pyrrolidines at the 7-position resulted in good solubility, highly potent activity, and good PDE7 selectivity. Among the synthesized compounds, compound 46 exhibited the greatest inhibition of ear edema in a phorbol ester-induced mouse model.

Discovery and SAR study of 2-(4-pyridylamino)thieno[3,2-d]pyrimidin-4(3H)-ones as soluble and highly potent PDE7 inhibitors.

The discovery and SAR study of a new series of soluble and highly potent phosphodiesterase (PDE) 7 inhibitors are described herein. We explored a new lead compound with improved solubility, which led to the discovery of a 2-(4-pyridylamino)thieno[3,2-d]pyrimidin-4(3H)-one series. The introduction of 3-piperidines at the 7-position resulted in the significant enhancement of PDE7 activity. In particular, compound 32 also showed strong PDE7 inhibitory activity; good selectivity against PDE3, 4, and 5; and good aqueous solubility.

Tetrahydroquinolines as a novel series of nonsteroidal selective androgen receptor modulators: structural requirements for better physicochemical and biological properties.

A rationally designed tetrahydroquinoline (1) for nonsteroidal selective androgen receptor modulators was modified for the exploration of promising compounds by Grieco three-component condensation using various dienophiles. Based on the in vitro effects and physicochemical properties of the synthesized compounds, compound 4c was selected for further study. Compound 4c increased the femoral bone mineral density as much as DHT, but it reduced the uterus effect compared with DHT in ovariectomized rats. Thus, compound 4c has desirable osteoanabolic effects with weak undesirable effects on the uterus in a female osteoporosis model.

Design and synthesis of tricyclic tetrahydroquinolines as a new series of nonsteroidal selective androgen receptor modulators (SARMs).

Some tricyclic tetrahydroquinolines (THQs) were found to have the potential of a new series of nonsteroidal selective androgen receptor modulators (SARMs). Compound 5b was first designed and synthesized under our hypothesis based on a four-point pharmacophoric requirement of the 3-carbonyl, 18-methyl, 17-hydroxyl, and 13-quaternary carbon groups of dihydrotestosterone (DHT). It was revealed that this compound exhibits not only a strong androgen receptor (AR) agonistic activity (EC(50)=9.2 nM) but also the highest selectivity in binding affinity to AR among the steroid hormone receptors. Furthermore, this compound showed a weak virilizing effect with retention of the desired anabolic effect as compared with DHT in vivo.

Discovery of 2-(cyclopentylamino)thieno[3,2-d]pyrimidin-4(3H)-one derivatives as a new series of potent phosphodiesterase 7 inhibitors.

The discovery of a new series of potent phosphodiesterase 7 (PDE7) inhibitors is described. Novel thieno[3,2-d]pyrimidin-4(3H)-one hit compounds were identified from our chemical library. Preliminary modifications of the hit compounds were performed, resulting in the discovery of a fragment-sized compound (10) with highly improved ligand efficiency. Compound design was guided by structure-activity relationships and computational modeling. The 6-substituted derivatives of the thienopyrimidinone showed diminished activity and enzyme selectivity. However, synthesis of the 7-substituted derivatives resulted in the discovery of 28e, a desirable lead compound that selectively inhibits PDE7 with single-digit nanomolar potency while displaying potent cellular efficacy.

Bone anabolic effects of S-40503, a novel nonsteroidal selective androgen receptor modulator (SARM), in rat models of osteoporosis.

A novel nonsteroidal androgen receptor (AR) binder, S-40503, was successfully generated in order to develop selective androgen receptor modulators (SARMs). We evaluated the binding specificity for nuclear receptors (NRs) and osteoanabolic activities of S-40503 in comparison with a natural nonaromatizable steroid, 5alpha-dihydrotestosterone (DHT). The compound preferentially bound to AR with nanomolar affinity among NRs. When S-40503 was administrated into orchiectomized (ORX) rats for 4 weeks, bone mineral density (BMD) of femur and muscle weight of levator ani were increased as markedly as DHT, but prostate weight was not elevated over the normal at any doses tested. In contrast, DHT administration caused about 1.5-fold increase in prostate weight. The reduced virilizing activity was clearly evident from the result that 4-week treatment of normal rats with S-40503 showed no enlargement of prostate. To confirm the bone anabolic effect, S-40503 was given to ovariectomized (OVX) rats for 2 months. The compound significantly increased the BMD and biomechanical strength of femoral cortical bone, whereas estrogen, anti-bone resorptive hormone, did not. The increase in periosteal mineral apposition rate (MAR) of the femur revealed direct bone formation activity of S-40503. It was unlikely that the osteoanabolic effect of the compound was attribute to the enhancement of muscle mass, because immobilized ORX rats treated with S-40503 showed a marked increase in BMD of tibial cortical bone without any actions on the surrounding muscle tissue. Collectively, our novel compound served as a prototype for SARMs, which had unique tissue selectivity with high potency for bone formation and lower impact upon sex accessory tissues.