Abstract: A recombinant collagen and a preparation method and use thereof, and in particular, a full-length collagen a1 chain produced through recombinant expression, and a preparation method and use thereof are provided. When a variant (which is denoted as a1 (I) M1) of a human type I collagen a1 chain (a1 (I) chain) and a variant (which is denoted as a1 (II) M6) of a human type II collagen a1 chain (a1 (II) chain) constructed in the present disclosure are produced through recombinant expression in Pichia pastoris, a main degradation product (a main degradation band) in substantially the same proportion as a target product (a target band) of a full-length a1 chain occurring during the recombinant expression of native full-length a1 (I) chain and a1 (II) chain is eliminated, and a yield of the target product is improved.

Abstract: Disclosed are a compound containing a fused ring, a use thereof and a pharmaceutical composition containing same. Provided are a compound as shown in formula I-A, a pharmaceutically acceptable salt thereof, a solvate thereof, a solvate of the pharmaceutically acceptable salt thereof or a crystal form thereof. The compound can significantly reduce the levels of HBsAg, HBeAg and HBV DNA, and can be used for preparing a drug for treating hepatitis B, and has good market prospects.

Abstract: Disclosed are a compound containing a fused ring, a use thereof and a pharmaceutical composition containing same. Provided are a compound as shown in formula I-A, a pharmaceutically acceptable salt thereof, a solvate thereof, a solvate of the pharmaceutically acceptable salt thereof or a crystal form thereof. The compound can significantly reduce the levels of HBsAg, HBeAg and HBV DNA, and can be used for preparing a drug for treating hepatitis B, and has good market prospects.

Abstract: Disclosed are a nitrogen-containing heterocyclic compound, a preparation method thereof, an intermediate thereof, a pharmaceutical composition thereof and a use thereof. The nitrogen-containing heterocyclic compound is a compound of formula I or formula II, a tautomer thereof, an optical isomer thereof, a deuterated compound thereof, a hydrate thereof, a solvate thereof or a pharmaceutically acceptable salt thereof, which can be used for treating a disease associated with TLR7 activity. The nitrogen-containing heterocyclic compound has a relatively high TLR7 agonist activity, high selectivity and good safety.

Abstract: Disclosed are a nitrogen-containing heterocyclic compound, preparation method, intermediate, pharmaceutical composition and use. The nitrogen-containing heterocyclic compound of the present invention has a novel structure, relatively high TLR7 agonist activity, high selectivity and good safety.