Aspergillic acid acetic acid gives a diketopiperazine. Hydrolysis with HBr yields a mixture of -leucine and -isoleucine. These reaction schemes can be seen below: Aspergillic acid Aspergillic acid is an organic chemical compound with the molecular formula CHNO. It has a pale yellow crystalline appearance. Aspergillic acid is most commonly known as an antibiotic and antifungal agent that is derived from certain strains of the fungus "Aspergillus flavus". In 1940 Edwin C. White and Justina H. Hill discovered that a fungal strain of "Aspergillus flavus" growing in a surface culture on a tryptone-salt was capable of producing a bactericidal filtrate. It has
Pyrosilicic acid the original solution is converted to pyrosilicic acid, which persists for 10 minutes or more. Pyrosilicic acid can also be obtained by controlled hydrolysis of the corresponding organic ester, such as hexaethyl pyrosilicate, with dilute sulfuric acid. Pyrosilicic acid Pyrosilicic acid is the chemical compound with formula , or -O-. It is one of the silicic acids. It has never been isolated in pure form, but it is assumed to be present in solutions of silicon dioxide (silica) in water, in equilibrium with other silicic acids and silicate ions. The salts of pyrosilicic acid are called pyrosilicates, such as sodium