摘要:
The present disclosure belongs to the field of pharmaceutical chemistry, and relates to a class of 2′,2-bisthiazole non-nucleoside compounds of following formula I, the preparation method and the pharmaceutical composition thereof. The compounds have both the anti-HBV and anti-HCV activities and are useful in treating hepatitides B and C. Pharmacokinetic tests showed the compounds have good bioavailability.
摘要:
The present disclosure belongs to the field of pharmaceutical chemistry, and relates to a class of 2′,2-bisthiazole non-nucleoside compounds of following formula I, the preparation method and the pharmaceutical composition thereof. The compounds have both the anti-HBV and anti-HCV activities and are useful in treating hepatitides B and C. Pharmacokinetic tests showed the compounds have good bioavailability.
摘要:
The present invention discloses a novel method for preparing and purifying 4-(6-Amino-purin-9-yl)-2(S)-hydroxy-butyric acid methyl ester. The preparation started from cheap and easily available L-malic acid, which was transformed to intermediate I after simultaneous protection of the groups of 1-carboxyl and 2-hydroxyl. The intermediate I was selectively reduced to intermediate alcohol II, whose hydroxyl group was further transformed to an easily leaving group to afford intermediate III. The intermediate III was nucleophilically substituted with adenine to afford intermediate IV. The intermediate IV was deprotected and methyl-esterified simultaneously in methanol in the presence of an acid or a base to afford crude 4-(6-Amino-purin-9-yl)-2(S)-hydroxy-butyric acid methyl ester, which was purified by recrystallization to afford the purified product. Comparing with the prior preparation methods, the present method has advantages in low cost, mild conditions, high retention of the chiral center during the reaction, high productivity, great improvement in the quality and yield of the product and great decrease in cost, and thus is suitable for the production on a large scale.
摘要:
The present invention generally relates to protein signalling. In particular, compounds that inhibit the Wnt protein signalling pathway are disclosed. Such compounds may be used in the treatment of Wnt protein signalling-related diseases and conditions such as cancer, degenerative diseases, type II diabetes and osteopetrosis.
摘要:
The invention relates a kind of antiviral agents, more concretely, relates to a kind of heterocyclic non-nucleoside compounds with the following structures, their preparation and pharmaceutical compositions including the compounds. The said compounds can be used as antiviral agents and as medicaments for treating diseases such as hepatitis B, influenza, herpes, HIV and so on.
摘要:
Water-soluble artemisinin derivatives, their preparation methods, the pharmaceutical compositions containing the same derivatives and the use thereof are disclosed. The artemisinin derivatives have following formula I. It has been proved by pharmacological tests that these compounds and compositions have evident immuno-suppressive activities, and may be used in the preparation of novel immuno-suppressants for treating the diseases caused by hyperfunction of human immunity (e.g. the auto-immune diseases such as lupus erythematosus, rheumatoid arthritis, multiple sclerosis and the like), and for inhibiting the graft rejection after cell or organ transplantation.
摘要:
A method for designing a secondary cutting structure for use in a bottom hole assembly, the method including defining initial design parameters for the secondary cutting structure and analyzing forces acting on the secondary cutting structure. Additionally, the method includes modifying at least one design element of the secondary cutting structure and simulating an effect of the modifying on both the secondary cutting structure and a primary cutting structure to determine if an improved condition is met. Also, a method for designing a drilling tool assembly, the method including defining initial drilling tool assembly design parameters including a primary cutting structure and a secondary cutting structure, and simulating a dynamic response of the drilling tool assembly. Additionally, the method includes adjusting at least one design element of the secondary cutting structure based on the dynamic response of the drilling tool assembly, determining if the adjusted design element improved a condition of the drilling, and repeating the simulating and adjusting until the condition is optimized.
摘要:
An integrated circuit including a metal-semiconductor field-effect transistor (MESFET) having a nominal intrinsic capacitance and requiring a negative voltage to bias the MESFET into a non-conduction state, a method of driving the MESFET and a power converter employing the integrated circuit and method. In one embodiment, the integrated circuit includes a driver including a bias capacitor integrated with the MESFET. The driver is configured to apply a positive voltage to bias the MESFET into a conduction state, and apply the negative voltage to bias the MESFET into the non-conduction state without employing an external negative bias source.
摘要:
A heavy weight drill pipe member is disclosed for use in drilling high angle and horizontal well bores in a corrosive environment. The heavy weight drill pipe member consists of a tubular member with a longitudinal bore therethrough, and includes connectors or tool joints attached at each distal end for connecting additional heavy weight drill pipe members. The tubular member and tool joints are preheated, water quenched and tempered to obtain a unique combination of hardness, a yield strength and impact strength for improved resistance to stress corrosion cracking and hydrogen embrittlement in a hydrogen sulfide environment. The tubular member includes a plurality of wear pads or protectors equidistantly spaced along the longitudinal axis of the tubular member to reduce bending stress in the pipe by limiting the degree of bend when the pipe is placed in compression in a high angle well bore. To reduce the chances of differential pressure sticking of the pipe when the pipe is used in high angle or horizontal well bores, each wear pad or protector is provided with spiral grooves therein. Each wear pad or protector may also be hard faced or hard banded to reduce wear.