https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Years of cumulative research can result in the development of a clinically useful drug, providing either a cure for a particular disease or symptomatic relief from a physiological disorder. A lead compound with a desired pharmacological activity may have associated with it undesirable side effects, characteristics that limit its bioavailability, or structural features which adversely influence its metabolism and excretion from the body. Bioisosterism represents one approach used by the medicinal chemist for the rational modification of lead compounds into safer and more clinically effective agents. The concept of bioisosterism is often considered to be qualitative and intuitive.1 The prevalence of the use of bioisosteric replacements in drug design need not be emphasized. This topic has been reviewed in previous years.2-5 The objective of this review is to provide an overview of bioisosteres that incorporates sufficient detail to enable the reader to understand the concepts being delineated. While a few popular examples of the successful use of bioisosteres have been included, the George Patani graduated with a B.Pharm. in 1992 from the College of Pharmaceutical Sciences, Mangalore University at Manipal, India. In 1996, he received his M.S. in Pharmaceutical Science at Rutgers University under the direction of Professor Edmond J. LaVoie. He is presently pursuing graduate studies in pharmaceutics. His current research interests are focused on drug design and controlled drug delivery.

https://www.mch.estranky.sk/file/228/1996chemrev96-3147-76_bioisosterism.pdf

Bioisosterism: A Rational Approach in Drug Design.

A new hierarchic classification structure for the taxa between the taxonomic levels of genus and class is Proposed for the actinomycete line of descent as defined by analysis of small subunit (16S) rRNA and genes coding for this molecule (rDNA). While the traditional circumscription of a genus of the actinomycete subphylum is by and large in accord with the 16S rRNA/rDNA-based phylogenetic clustering of these organisms. most of the higher taxa proposed in the past do not take into account the phylogenetic clustering of genera. The rich chemical, morphological and physiological diversity of phylogenetically closely related genera makes the description of families and higher taxa so broad that they become meaningless for the description of the enclosed taxa. Here we present a classification system in which phylogenetically neighboring taxa at the genus level are clustered into families, suborders, orders, subclasses, and a class irrespective of those phenotypec characteristics on which the delineation of taxa has been based in the past. Rather than being based on a listing of a wide array of chemotaxonomic, morphological, and physiological properties, the delineation is based solely on 16S rDNA/rRNA sequence-based phylogenetic clustering and the presence of taxon-specific 16S rDNA RNA signature nucleotides.

/pdf/proposal-for-a-new-hierarchic-classification-system-4ivafhm3px.pdf

Proposal for a New Hierarchic Classification System, Actinobacteria classis nov.

Isolation and synthesis of biologically active carbazole alkaloids

Occurrence, Biogenesis, and Synthesis of Biologically Active Carbazole Alkaloids

Soil Actinomycetales that produce antibiotics during growth on agar but not in submerged culture were searched for and about 25 strains were obtained One of these, Streptomyces halstedii, strain SF-1993, which produces an antibiotic designated SF-1993 was studied taxonomically and morphologically The antibiotic-productivity of strain SF-1993 was correlated with mycelial morphology The vegetative mycelium was filamentous in antibiotic-producing agar cultures, but fragmented in non-producing submerged cultures By maintaining submerged cells filamentous, production of antibiotic in the submerged fermentations was accomplished Filamentation was maintained by the use of diluted media or non-fragmented mutant substrains

Studies on Actinomycetales producing antibiotics only on agar culture. I. Screening, taxonomy and morphology-productivity relationship of Streptomyces halstedii, strain SF-1993.

Amicoumacin-a, a new antibiotic with strong antiinflammatory and antiulcer activity

Sir: A new indolocarbazole antibiotic SF-2370 has been found in the culture broth of Actinomadura sp. SF-2370 which was isolated from a soil sample collected at Shimizu, Shizuoka Prefecture, Japan. The antibiotic is weakly active against some bacteria and fungi. In this communication, the isolation, characterization, and structural elucidation by the spectral studies are reported. Actinomadura sp. SF-2370 was cultured at 28°C for 5 days in a medium (600 ml) containing glucose 1.5%, wheat germ 1.0%, corn steep liquor 1.0%, Pharmamedia (Traders Protein, Buckeye Cellulose Corp.) 0.5 %, CaCO3 (adjusted to pH 7.0) 0.3% in a 1-liter jar fermentor. Vegetative inoculum, 20 ml (3.3%) grown on a rotary shaker for 7 days at 28°C in a medium containing glucose 2.0%, wheat germ 1.0%, peptone 0.5%, yeast extract 0.5% and CaCO, (adjusted to pH 7.0) 0.1 % was used. The antibiotic was assayed by the paper disc method against Micrococcus luteus. The culture broth was filtered at pH 7.8 and the antibiotic in the mycelium was extracted with 70% aqueous acetone (500 ml). The extract was concentrated to remove acetone and the antibiotic in the concentrate was extracted twice with EtOAc (250 ml). The extract was dried on Na2SO4 and concentrated to give an oily residue. n-Hexane was added to the residue to give the precipitates (286 mg). The precipitates were chromatographed on a column of silica gel (60 ml) developed with chloroform EtOAc (10: 1) to yield a pale yellow powder (216 mg). The powder was further purified by preparative TLC using EtOAc (Rf 0.31) as a developing solvent. Recrystallization from MeOH gave pale yellow crystals of antibiotic SF-2370 (79 mg) (1): mp 261-262-C (dec), [a] 1 +57° (c 0.1, MeOH). Anal Calcd for C27H21N3O,: C 69.38, H 4.50, N 8.99. Found: C 69.50, H 4.74, N 8.88. MS m/z obsd: 467.1473 (M+), calcd for C27H21N3O5: 467.1479. UV ),,',11.0.11 nm (E; m) 228 (725), 250 (717), 265 (sh), 280 (sh), 290 (1,708), 320 (sh), 335 (432), 350 (325) and 367 (353). No characteristic shifts on UV absorption maxima were observed in acidic and alkaline solutions. IR v,,,as (KBr) cm-1 3400 (OH, NH), 1730 (ester), 1670 (amide), 1455, 1255 (ether) and 750 (aromatic). 'H and 13C

A new antibiotic sf-2370 produced by actinomadura

Eight actinomycete strains originally isolated from soil and plant samples were studied to determine their taxonomic status. All isolates produced branching substrate mycelia, but no distinct aerial hyphae. Relatively short chains of nonmotile spores (10 to 30 spores per chain) were borne on the tips of sporophores arising directly from the agar surface. The chemotaxonomic characteristics of the isolates, with the exception of the menaquinone profile, coincided with those of members of the family Streptosporangiaceae Goodfellow, Stanton, Simpson, and Minnikin 1990. Furthermore, the results of a phylogenetic analysis performed with 5S rRNA support the conclusion that the isolates should be classified in this family. The isolates differed from members of the constituent genera of the Streptosporangiaceae in morphological characteristics and menaquinone composition. Therefore, we propose a new genus for the strains, Herbidospora. The type species and type strain are Herbidospora cretacea sp. nov. and strain K-319 (= JCM 8553), respectively.

Herbidospora gen. nov., a New Genus of the Family Streptosporangiaceae Goodfellow et al. 1990

Pyrrolomycins C, D and E, new members of pyrrolomycins produced by Actinosporangium vitaminophilum SF-2080, have been isolated by chromatography on a basic alumina column. Three antibiotics have chlorinated pyrrole nuclei linked directly or via carbonyl function to the dichlorophenol moiety. Pyrrolomycins C and E are active against Gram-positive bacteria, while the spectrum of pyrrolomycin D is broad including Gram-positive, Gram-negative bacteria and fungi.

https://www.jstage.jst.go.jp/article/antibiotics1968/36/10/36_10_1263/_pdf

Takashi Shomura

Papers

Studies on Actinomycetales producing antibiotics only on agar culture. I. Screening, taxonomy and morphology-productivity relationship of Streptomyces halstedii, strain SF-1993.

Amicoumacin-a, a new antibiotic with strong antiinflammatory and antiulcer activity

A new antibiotic sf-2370 produced by actinomadura

Herbidospora gen. nov., a New Genus of the Family Streptosporangiaceae Goodfellow et al. 1990

Pyrrolomycins C, D and E, new members of pyrrolomycins.