Abstract: This invention provides compounds having antitumor effect, namely a compound represented by the following formula (I) or (Ia) having various substituents in which G and G1 are condensed tricyclic heterocyclic rings or salts thereof, and a compound represented by the following formula (Ib) having various substituents or salts thereof.

Abstract: The present invention relates to cis- and trans-forms of pyrazole derivatives, salts thereof, or agents containing the same, and represented by the general formula (I): wherein G represents a nitrogen containing saturated heterocyclic structure represented by the following formula: These compounds exhibit anti-tumor activity on 5-FU-resistant tumors and effects on P glycoprotein expressing, multiple-drug resistant tumors. An example of a pyrazole derivative which demonstrates 50% inhibition of tumor cell growth is 3-[4-(3-chloro-5-fluorophenyl)-1piperazinyl]-1-[1-(3-chloro-2-pyridyl)-5-methyl-4-pyrazolyl)-1-trans-propene hydrochloride. Synthesis of the compounds represented by formula (I) can be prepared by any one of various routes such as a Mannich reaction, a Wittig reaction, reductive amination or substitution by allylation.

Abstract: Accordingly, an object of this invention is to provide a hexa-cyclic compound represented by the following general formula: wherein R1 and R2 individually represent a hydrogen atom, a hydroxyl group, a C1-6 alkyl group (“C1-6 alkyl group means an alkyl group having 1 to 6 carbon atoms. Hereinafter defined in the same manner.) The present inventors have conducted extensive studies for the purpose of obtaining camptothecin derivatives with more excellent activity and higher safety, as well as excellent characteristics required for a drug to be administered, and found that hexa-cyclic compounds obtained by the addition of a water-soluble ring to camptothecin had characteristics superior to camptothecin. This finding has led to the completion of this invention.

Abstract: The present invention relates to cis- and trans-forms of pyrazole derivatives, salts thereof, or agents containing the same, and represented by the general formula (I): wherein G represents a nitrogen containing saturated heterocyclic structure represented by the following formula: These compounds exhibit anti-tumor activity on 5-FU-resistant tumors and effects on P glycoprotein expressing, multiple-drug resistant tumors. An example of a pyrazole derivative which demonstrates 50% inhibition of tumor cell growth is 3-[4-(3-chloro-5-fluorophenyl)-1 piperazinyl]-1-[1-(3-chloro-2-pyridyl)-5-methyl-4-pyrazolyl)-1-trans-propene hydrochloride. Synthesis of the compounds represented by formula (I) can be prepared by any one of various routes such as a Mannich reaction, a Wittig reaction, reductive amination or substitution by allylation.

Abstract: The present invention provides a novel compound which is represented by formula (I): ##STR1## wherein preferable examples of R.sup.1 to R.sup.6 are as follows; R.sup.1 and R.sup.2 are each an alkyl group optionally substituted by a halogen atom, an amino group, a hydroxyl group, an alkoxyl group or a thiol group, a hydrogen atom, a halogen atom or an alkoxyl group; R.sup.3 is a hydrogen atom; R.sup.4 is a methyl group; R.sup.5 is a hydrogen atom or an alkyl group; and R.sup.6 is a group of the formula: ##STR2## wherein Z is a phenyl group; and has an antitumor effect.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound by the condensation-ring closing reaction. It is abundantly water-soluble, and has an excellent antitumour activity and a high degree of safety, and can be applied as an antitumour medicine for curing tumors of various kinds.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound by the condensation-ring closing reaction. It is abundantly water-soluble, and has an excellent antitumor activity and a high degree of safety, and can be applied as an antitumor medicine for curing tumors of various kinds.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound by the condensation-ring closing reaction. It is abundantly water-soluble, and has an excellent antitumor activity and a high degree of safety, and can be applied as an antitumor medicine for curing tumors of various kinds.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound by the condensation-ring closing reaction. It is abundantly water-soluble, and has an excellent antitumour activity and a high degree of safety, and can be applied as an antitumour medicine for curing tumors of various kinds.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formura: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound through Friedlaender reaction. It has an excellent antitumour activity and a high degree of safety, and can be applied as an antitumour medicine for curing tumors of various kinds.

Abstract: A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound through Friedlaender reaction. It has an excellent antitumor activity and a high degree of safety, and can be applied as an antitumor medicine for curing tumors of various kinds.

Abstract: Novel cephalosporin derivatives and salts thereof are disclosed. These compounds exhibit excellent antimicrobial activity against a wide variety of Gram-negative and Gram-positive bacteria and also have other excellent characteristics as a medicine such as stability and low toxicity. These compounds can be administered in a form of subcutaneous, intravenous or intramuscular injections.

Abstract: A pyranoindolizine derivative represented by the following general formula (I): ##STR1## wherein R means a hydrogen atom or hydroxyl group and Q denotes >C.dbd.O or ##STR2## with a proviso that Q is other than >C.dbd.O when R is a hydrogen atom. Its preparation process is also described.

Abstract: In a method of forming an electric welded steel tube, wherein a hot-rolled sheet is formed into a cylindrical shape, with the central portion thereof being lowered as the forming progresses, and thereafter, subjected to reduction in the circumferential direction of the tube by means of tandem type fin-pass rolls to be finished into the tube, the proper forming condition ranges capable of eliminating occurrence of edge waves in the tube seam edge portion and/or of cambers in the longitudinal direction of the tube by three forming conditions factors including the downhill value D.sub.H (downhill coefficient .eta.) of the hot-rolled sheet, the fin-pass total reduction R of the tandem type fin-pass rolls and the distribution of the fin-pass reduction (the distribution ratio .delta. of the first fin-pass reduction).

Abstract: High chromium steels having extremely low carbon and nitrogen contents are produced by blowing more than 15 up to 40 Nl/min per ton of molten steel of an inert gas into a high chromium steel containing 0.8 to 2.5% of C and 10 to 35% of Cr in a ladle under a reduced pressure from bottom of a ladle and concurrently blowing oxygen gas to the molten steel surface to form 1 to 100 kg per ton of the molten steel of a slag containing not less than 20% of SiO.sub.2 and not more than 25% of Cr.sub.2 O.sub.3 at the end of oxygen blowing, terminating the oxygen blowing when the carbon concentration in the molten steel becomes not more than 0.020%, and subsequently blowing 6 to 40 Nl/min per ton of molten steel of an inert gas under a high vacuum of not more than 10 torr.

Abstract: A method of denitriding a high chromium molten steel with a minimum chromium loss is disclosed. A high chromium molten steel containing 0.8-2.5% of C and 10-35% of Cr is denitrided to a final nitrogen content of not more than 40 ppm in a ladle under vacuum by flowing an inert gas into molten steel at a flow rate of not less than 15 Nl/min per ton of molten steel and at the same time blowing oxygen gas against molten steel until carbon content [C] in molten steel satisfies the following equations (1) and (2) in accordance with the carbon content prior to decarburization [C] of molten steel:[C].ltoreq.[C] 0.3, when 0.8.ltoreq.[C].ltoreq.1.0% (1)[c].ltoreq.55/70[c]--6/70, when 1.0.ltoreq.[C].ltoreq.2.5% (2).

Abstract: A method of producing alloy steels having an extremely low carbon content of not higher than 30 ppm is disclosed. The alloy steels can be obtained by vacuum treating a preliminarily decarburized molten steel in the presence of a proper amount of a slag containing specifically limited amounts of chromic oxide and silicon oxide under an inert gas atmosphere by means of a commonly used degassing apparatus.