Penicillin notatum

Antibiotics, e.g. Benzylpenicillin Gentamicin Nystatin Penicillin notatum, P. chrysogenum Micromonospora purpurea Streptomyces noursei Antibacterial drug Antibacterial drug Antifungal drug... 

Plants are not the only natural products used as a source for drugs. Microorganisms have, of course, been extensively screened for antibiotics since Alexander Fleming s discovery of the antibacterial activity of Penicillin notatum in the 1920s. Numerous... 

Benzylpenicillin Penicillin notatum, P. chrysogenum Antibacterial drug... 

Penicillins. Since the discovery of penicillin in 1928 as an antibacterial elaborated by a mold, Penicillium notatum the global search for better antibiotic-producing organism species, radiation-induced mutation, and culture-media modifications have been used to maximize production of the compound. These efforts have resulted in the discovery of a variety of natural penicillins differing in side chains from the basic molecule, 6-aminopenici11anic acid [551-16-6], These chemical variations have produced an assortment of dmgs having diverse pharmacokinetic and antibacterial characteristics (see Antibiotics, P-lactams). 

The antibacterial properties of a moldpenicillium notatum were first observed by Fleming in 1928. The active compound, penicillin N , was isolated ten years later, and soon thereafter, large-scale production of a closely-related compound penicillin G was initiated. 

Figure 6.4 Stylised representation of changing parameters and penicillin production in cultures of Penldlllum notatum, grown as a surface culture on Czapek-Dox medium (adapted from Hockenhull DJ-D "Production of Antibiotics by Fermentation in Essays in Applied Microbiology edited by Norris J R Richmond M H 1981. John Wiley Sons Ltd Chichester).

The P. notatum took up the P-phenyl ethylamine, converted it to p-phenylacetate, which was subsequently attached to the 6-amino group of penirillanic add to give benzyl penicillin (penidllin G). We can represent this process by ... 

The mold isolated by Alexander Fleming in early 1940s was Penicillium notatum, who noted that this species killed his culture of Staphylococcus aureus. The production of penicillin is now done by a better penicillin-producing mould species, Penicillium chryso-genum. Development of submerged culture techniques enhanced the cultivation of the mould in large-scale operation by using a sterile air supply. 

Naturally occurring. For example, those produced by fermentation of moulds such as Penicillium notatum and P. chrysogenum. The most important examples are benzylpenicillin (penicillin G) and phenoxymethylpenicillin (penicillin V). 

Penicillins (A). The parent substance of this group is penicillin G (ben-zylpenidllin]. It is obtained from cultures of mold fungi, originally from Pen-icillium notatum. Penicillin G contains the basic structure common to all penicillins, 6-amino-penicillanic acid (p. 

Sir Alexander Fleming first noted the ability of the mould P. notatum to produce an antibiotic substance (which he called penicillin) in 1928. However, he also noted that when penicillin was added to blood in vitro, it lost most of its antibiotic action, and Fleming consequently lost interest in his discovery. In the late 1930s, Howard Florey, Ernst Chain and Norman Heatley began to work on penicillin. They purified it and, unlike Fleming, studied its effect on live animals. They found that administration of penicillin to mice after their injection with lethal doses of streptococci protected the mice from an otherwise certain death. 

In 1928, Sir Alexander Fleming found that a diffusible substance was elaborated by Penicillium notatum (a fungus) which prevented the growth of surrounding bacterial colonies in culture plate. He named this as penicillin but this discovery remained a scientific curiosity for more than a decade. This work was followed up by Chain, Falk and Florey who established the efficacy of penicillin in 1941 and in 1945, Fleming, Chain and Florey were awarded the Nobel Prize. 

Penicillin was originally extracted from the mould Penicillium notatum but now it is extracted from its related mould Penicillium chrysogenum due to its high yield. Penicillin consists of thiazolidine ring fused with a beta lactam ring which is essential for its antibacterial activity. These two rings forms a nucleus named as 6-aminopenicillanic acid. 

Penicillin is but one of a series of closely related compounds isolated from fermentation broths of Penicillium notatum. This compound, also known as penicillin G (1-1) or benzyl penicillin, is quite unstable and quickly eliminated from the body. Initial approaches to solving these problems, as noted above, consisted of preparing salts of the compound with amines that would form tight ion pairs that in effect provided a controlled release of the active dmg. Research on fermentation conditions aimed at optimizing fermentation yields succeeded to the point where penicillin G or penicillin V (26-1), in which the phenylacetyl group is replaced by phenoxyacetyl, is now considered a commodity chemical. Another result of this research was the identification of fermentation conditions that favored the formation of the deacylated primary amine, 6-aminopenicillanic acid (2-4) or 6-APA, a compound that provided the key to semisynthetic compounds with superior pharmaceutical properties than the natural material. An elegant procedure for the removal of the amide side chain proved competitive with 6-APA from fermentation. This method, which is equally applicable to penicillin V, starts by conversion of the acid to the corresponding silyl ester (2-1). Treatment of that compound with phosphoms pentachloride in the... 

The penicillin group of antibiotics, also known as (3-lactam antibiotics, has revolutionized the history of modern medicine, by their effectiveness against several pathogenic bacterial species that cause various forms of infections. Penicillin G, the parent of all these antibiotics, was first isolated from a fungal species, Penicillium notatum. Since the discovery of this antibiotic, several modifications have been introduced to the parent strucmre in order to enhance the activity, increase the acid resistance, facilitate bioavailability... 

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