Abstract: The present invention provides a 2-arylmethylazetidine-carbapenem-3-carboxylic acid ester derivative or its pharmaceutically acceptable salt, a process for the preparation thereof, and a pharmaceutical composition comprising the same. The 2-arylmethylazetidine-carbapenem-3-carboxylic acid ester derivatives or their pharmaceutically acceptable salts show high oral absorption rate, and thus can be orally administered. The active metabolites thereof have a broad spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria and excellent antibacterial activities against methicillin-resistant Staphylococcus aurus (MRSA) and quinolone-resistant strains (QRS). In particular, the acid addition salts of the 2-arylmethylazetidine-carbapenem-3-carboxylic acid ester derivatives are obtained in crystalline forms having excellent stability.

Abstract: The present invention provides a process for preparing an acid addition salt of a synthetic intermediate for carbapenem antibiotics and a novel acid addition salt of a synthetic intermediate for carbapenem antibiotics obtained from the process. The present invention also provides a process for preparing a carbapenem antibiotic using the acid addition salt. According to the process of the present invention, an acid addition salt of a synthetic intermediate for carbapenem antibiotics can be prepared in a high yield and high purity, without conducting column chromatography. Thus, the process of the present invention can be applied to mass production with an industrial scale. Furthermore, since the acid addition salts have solid forms, they are easy to handle and keep in a manufacturing site.

Abstract: A 2-arylmethylazetidine carbapenem derivative of formula (I) or a pharmaceutically acceptable salt thereof exhibits a wide spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria and excellent antibacterial activities against resistant bacteria such as methicillinresistant Staphylococcus aureus (MRSA) and quinolone-resistant strains (QRS):

Abstract: A 2-arylmethylazetidine carbapenem derivative of formula (I) or a pharmaceutically acceptable salt thereof exhibits a wide spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria and excellent antibacterial activities against resistant bacteria such as methicillinresistant Staphylococcus aureus (MRSA) and quinolone-resistant strains (QRS).

Abstract: Disclosed herein is a compound having formula (I), wherein R.sub.1 represents a hydrogen atom or a C.sub.1-3 alkyl group; and R.sub.2 represents phenyl and furanyl group, or a group represented by the formula: --C(R.sub.a).dbd.C(R.sub.b)(R.sub.c), wherein R.sub.a, R.sub.b, and R.sub.c, being the same or different from each other, means hydrogen atom or methyl or phenyl group. The present invention further provides a method for preparing the compound (I) and a composition comprising as an active ingredient the compound (I). The compound (I) of the present invention can effectively inhibit the expression of enzymes involved in phase I reaction while activating the expression of enzymes involved in phase II reaction, thereby can be advantageously used to protect liver from being injured by various chemicals.