Friedrich Wöhler FRS(For) HonFRSE was a German chemist known for his work in both organic and inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the first to prepare several inorganic compounds, including silane and silicon nitride.
Urea, also known as carbamide, is an organic compound with chemical formula CO(NH2)2. This amide has two amino groups joined by a carbonyl functional group. It is thus the simplest amide of carbamic acid.
Xanthine is a purine base found in most human body tissues and fluids, as well as in other organisms. Several stimulants are derived from xanthine, including caffeine, theophylline, and theobromine.
Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl.
Sir Hans Adolf Krebs, FRS was a German-born British biologist, physician and biochemist. He was a pioneer scientist in the study of cellular respiration, a biochemical process in living cells that extracts energy from food and oxygen and makes it available to drive the processes of life. He is best known for his discoveries of two important sequences of chemical reactions that take place in the cells of humans and many other organisms, namely the citric acid cycle and the urea cycle. The former, often eponymously known as the "Krebs cycle", is the key sequence of metabolic reactions that provides energy in the cells of humans and other oxygen-respiring organisms; and its discovery earned Krebs a Nobel Prize in Physiology or Medicine in 1953. With Hans Kornberg, he also discovered the glyoxylate cycle, which is a slight variation of the citric acid cycle found in plants, bacteria, protists, and fungi.
Ureases, functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous bacteria, fungi, algae, plants, and some invertebrates, as well as in soils, as a soil enzyme. They are nickel-containing metalloenzymes of high molecular weight.
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as inorganic chemistry.
Platonia insignis, the sole species of the genus Platonia, is a tree of the family Clusiaceae native to South America in the humid forests of Brazil, Paraguay, parts of Colombia and northeast to Guyana; especially in Amazon Rainforest. Common names include bacuri, maniballi, naranjillo and bacurizeiro.
Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, sulphamic acid and sulfamidic acid, is a molecular compound with the formula H3NSO3. This colourless, water-soluble compound finds many applications. Sulfamic acid melts at 205 °C before decomposing at higher temperatures to water, sulfur trioxide, sulfur dioxide and nitrogen.
In organic chemistry, a carbodiimide is a functional group with the formula RN=C=NR. They are exclusively synthetic. A well known carbodiimide is dicyclohexylcarbodiimide, which is used in peptide synthesis. Dialkylcarbodiimides are stable. Some diaryl derivatives tend to convert to dimers and polymers upon standing at room temperature, though this mostly occurs with low melting point carbodiimides that are liquids at room temperature. Solid diaryl carbodiimides are more stable, but can slowly undergo hydrolysis in the presence of water over time.
Erythrosine, also known as Red No. 3, is an organoiodine compound, specifically a derivative of fluorone. It is a pink dye which is primarily used for food coloring. It is the disodium salt of 2,4,5,7-tetraiodofluorescein. Its maximum absorbance is at 530 nm in an aqueous solution, and it is subject to photodegradation.
The Wöhler synthesis is the conversion of ammonium cyanate into urea. This chemical reaction was described in 1828 by Friedrich Wöhler. It is often cited as the starting point of modern organic chemistry. Although the Wöhler reaction concerns the conversion of ammonium cyanate, this salt appears only as an (unstable) intermediate. Wöhler demonstrated the reaction in his original publication with different sets of reactants: a combination of cyanic acid and ammonia, a combination of silver cyanate and ammonium chloride, a combination of lead cyanate and ammonia and finally from a combination of mercury cyanate and cyanatic ammonia.
Biuret is a chemical compound with the chemical formula HN(CONH2)2. It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula R1R2N−C(=O)−N(R3)−C(=O)−NR4R5, where R1, R2, R3, R4 and R5 are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. As such, it is an undesirable impurity in urea-based fertilizers. As biuret is toxic to plants, its percentage in fertilizers must be kept low.
Xanthone is an organic compound with the molecular formula O[C6H4]2CO. It is a white solid.
Xanthene (9H-xanthene, 10H-9-oxaanthracene) is the organic compound with the formula CH2[C6H4]2O. It is a yellow solid that is soluble in common organic solvents. Xanthene itself is an obscure compound, but many of its derivatives are useful dyes.
Oxamide is the organic compound with the formula (CONH2)2. This white crystalline solid is soluble in ethanol, slightly soluble in water and insoluble in diethyl ether. Oxamide is the diamide derived from oxalic acid, and the hydrate of cyanogen.
A xanthonoid is a chemical natural phenolic compound formed from the xanthone backbone. Many members of the Clusiaceae contain xanthonoids.
Selenourea is the organoselenium compound with the formula SeC(NH2)2. It is a white solid. This compound features a rare example of a stable, unhindered carbon-selenium double bond. The compound is used in the synthesis of selenium heterocycles. Compared to urea, the oxo-analog of selenourea, few studies have been done on the compound due to the instability and toxicity of selenium compounds. Selenourea is toxic if inhaled or consumed.
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants, and some species of fungi that do not form lichens.
Griseoxanthone C is an organic compound in the structural class of chemicals known as xanthones. Its chemical formula is 1,6-dihydroxy-3-methoxy-8-methylxanthen-9-one, and its molecular formula is C15H12O5. It is found in a plant and some fungi, including a lichen.
