Abstract: 2,3-disubstituted-4-hydroxyquinoline derivatives of the general formula (I): ##STR1## [wherein R.sup.1 represents a hydrogen atom or R.sup.3 CO-- (wherein R.sup.3 is a lower alkyl group); R.sup.2 represents a hydrogen atom, --CH.sub.3 or --C.sub.2 H.sub.5 ; A represents ##STR2## and W represents a hydrogen atom, or 1- 4 halogen atoms or alkyl groups which are substituted at the nucleus and may be the same or different] have a strong antagonistic action on leukotriene D.sub.4.

Abstract: A novel substance having anthelmintic activity, the PF 1022 substance, which is produced by cultivating a fungal strain capable of producing the substance and recovering the substance from the culture.

Abstract: A novel compound having an intense insecticidal activity and a process for producing the same which comprises culturing a strain belonging to the genus Humicola and isolating the compound from the culture.

Abstract: Novel substances exhibiting antimicrobial activity and antitumor activity, a process for producing them by cultivating a microorganism belonging to the genus Streptomyces and capable of producing them and derivatives of such substances.

Abstract: An antibiotic substance represented by formula (I) ##STR1## or a pharmaceutically acceptable salt thereof, which is produced by cultivating a microorganism belonging to the genus Streptomyces and isolating the substance from the cultured cells.

Abstract: Novel antibiotic SF-2288 is produced by fermentation of an actinomycete belonging to the genus Actinomadura in nutrient medium. Based on its physico-chemical and biological properties, antibiotic SF-2288 possesses an excellent antimicrobial activity against Gram-positive and Gram-negative microorganisms and antiviral activity.

Abstract: Disclosed is an antiviral agent comprising as an active component a substance SF-2140 described in detail in the specification, and a pharmaceutically acceptable carrier. Also disclosed is a method for treatment of viral diseases comprising administering a pharmaceutically effective amount of the substance SF-2140.

Abstract: Essentially pure plasmids derived from Actinomycetes are described which have at least one restriction cleavage site for specific restriction enzyme and have molecular weight of less than 1.0.times.10.sup.7.

Abstract: An antibiotic SF-2103A substance or a salt thereof, and a process for the production thereof are described, and the process comprises cultivating an antibiotic SF-2103A substance-producing strain in a nutrient medium and recovering the desired substance from the culture broth.

Abstract: Disclosed is a novel antibiotic SF-2107 series substance consisting essentially of Substance SF-2107 A-1, Substance SF-2107 B and/or Substance SF-2107 C, each having the phisico-chemical properties as described in the specification, which substance exhibits an antibacterial activity against both gram-positive and gram-negative bacteria and is useful for pharmaceuticals, bactericides, disinfectants, etc. Also disclosed is a process for preparing the substance.

Abstract: Antibiotics, designated as SF-2080A substance and SF-2080B substance, are described, and are obtained by cultivating an SF-2080 substance-producing strain belonging to the genus Streptomyces, for example, Streptomyces sp. SF-2080 (FERM-P No. 5072, ATCC No. 31673), in a nutrient medium, and recovering the desired substance from the culture.

Abstract: A new antibiotic SF-1130-x.sub.3 substance is produced by cultivating a microorganism Streptomyces myxogenes SF-1130 (deposited under FERM-P. 676 and ATCC 31305) in a liquid culture medium under aerobic conditions, and this antibiotic may be isolated from the fermentation broth of said microorganism and is useful as an inhibitor to .alpha.-glucosidase and saccharase. Besides, this antibiotic, when orally given, is useful as a drug for suppressing an elevation in the level of blood sugar in living animals which have taken starch and/or sugars.

Abstract: New antibiotic, SF-2052 substance is produced by cultivating a microorganism, Dactylosporangium matsuzakiense SF-2052 now deposited under FERM-P 4670 or ATCC No. 31570 in a liquid culture medium under aerobic conditions, and this antibiotic may be isolated from the culture broth by conventional method and is useful as antibacterial agent.

Abstract: L-2-Amino-4-methylphosphinobutyric acid (L-MPGA) which is useful as bactericide and herbicide can be prepared by optical resolution of its racemic mixture, D,L-MPGA with the action of a microbial acylase. The process comprises providing D,L-MPGA in the form of its N-acyl derivative, reacting N-acyl-D,L-MPGA in an aqueous medium with a microbial acylase having an optically specific hydrolytic activity, whereby selectively eliminating the acyl group of N-acyl-L-MPGA to give a mixture of L-MPGA and N-acyl-D-MPGA and isolating L-MPGA from the mixture. The acylase is produced by cultivating a microbial strain belonging to the genus Pseudomonas, Streptomyces or Aspergillus, particularly Pseudomonas maltophilia BN-233, Streptomyces violascens SF 2072, Streptomyces diastatochromogenes SF 2073, Aspergillus sp. KS-101 or Aspergillus sp. KS-102.

Abstract: New antibiotics, SF-2050 substance and SF-2050B substance are produced by cultivating a microorganism Streptomyces sp. SF-2050 now deposited under FERM-P 4358 and under ATCC. 31450 in a liquid culture medium under aerobic conditions, and these antibiotics may be isolated from the fermentation broth and useful as an antibacterial agent. These antibiotics have an activity inhibitory to .beta.-lactamase.

Abstract: A new antiviral agent is now provided, which contains as the active ingredient at least one known glycine derivative of the formula: ##STR1## wherein R is a hydrogen atom, R' is a group --CH.sub.2 NH.sub.2, --CH.sub.2 NHCONH.sub.2, --CH.sub.2 NHCONHOH, --CH.sub.2 CH.sub.2 PO(OH).sub.2, ##STR2## or R and R' taken together form a group ##STR3## and R" is a hydrogen atom or a lower alkyl group, or a pharmaceutically acceptable salt of said glycine derivative. This antiviral agent is useful for therapeutic prevention and treatment of diseases caused by various kinds of viruses.

Abstract: Substance SF-1739 derivatives, Substance SF-1739 HP, Substance SF-1739 HP-C, Substance SF-1739 HP-F, Substance SF-1739 HP-3 and Substance SF-1739 HP-5, the physico-chemical properties of which derivatives are described in the specification; processes for preparing such SF-1739 derivatives; and antimicrobial compositions containing at least one of the said Substance SF-1739 derivatives.

Abstract: An antibiotic SF-1942 substance produced by cultivating an SF-1942 substance producing strain of the genus Streptomyces in a nutrient medium under aerobic conditions to produce and accumulate the SF-1942 substance in the nutrient medium and isolating the SF-1942 substance from the fermentation broth followed by purification and a process for the production of the antibiotic SF-1942 substance. The SF-1942 substance is effective as an antimicrobial agent and an antitumor agent against Sarcoma 180 tumor cells in mice.

Abstract: A novel antibiotic substance SF-1540 and a process for preparing the same which comprises culturing a substance SF-1540-producing microorganism belonging to the genus Streptomyces in a medium and isolating and recovering the substance SF-1540 from a cultured broth; a novel derivative of the substance SF-1540 and a process for preparing the same which comprises treating said antibiotic substance SF-1540 with methanol to form the corresponding antibiotic substance SF-1540 derivative.

Abstract: A new antibiotic SF-1771 substance is produced by cultivating a new strain, Streptomyces toyocaensis SF-1771, in a liquid culture medium under aerobic conditions. This antibiotic may be isolated from the fermentation broth by treating the broth filtrate with a synthetic adsorbent resin for adsorption of the active compound and eluting the resin with an aqueous alcohol or aqueous acetone, followed by chromatographic purification. SF-1771 substance is a copper-containing antibiotic which shows antibacterial activity against Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. Removal of the copper component from SF-1771 substance by treatment with hydrogen sulfide, an alkali metal sulfide or a copper-chelating agent gives SF-1771-B substance containing no copper component which shows antibacterial activity as high as but a toxicity lower than SF-1771 substance.