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Baishouwubenzophenone
Baishouwubenzophenone is a naturally occurring atropisomeric compound with the formula CHO. Classified as a benzophenone derivative, it has been isolated from the roots of several species in the genus ''Cynanchum'', including ''Cynanchum wilfordii'', ''Cynanchum auriculatum'' (now ''Vincetoxicum auriculatum''), and ''Cynanchum bungei''. Structure and properties Baishouwubenzophenone has the molecular formula CHO. Structurally, it consists of two aromatic rings connected by a central carbonyl group, characteristic of the benzophenone framework. The molecule contains multiple hydroxyl groups, which contribute to its positive reaction with ferric chloride (FeCl), indicative of phenolic functionality. Baishouwubenzophenone is an example of a non- biaryl atropisomer. The presence of bulky substituents ortho to the carbonyl bridge on both aromatic rings results in restricted rotation around the Ar–CO–Ar axis, giving rise to stable atropisomers. Both (R)- and (S)-enantiomers have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynanchum
''Cynanchum'' is a genus of about 300 species including some swallowworts, belonging to the family Apocynaceae. The taxon name comes from Greek ''kynos'' (meaning "dog") and ''anchein'' ("to choke"), hence the common name for several species is dog-strangling vine. Most species are non-succulent climbers or twiners. There is some evidence of toxicity. Morphology These plants are perennial herbs or subshrubs, often growing from rhizomes. The leaves are usually oppositely arranged and sometimes are borne on petioles. The inflorescences and flowers come in a variety of shapes. Like other species of the milkweed family, these plants bear follicles, which are podlike dry fruits. Distribution These species are found throughout the tropics and subtropics. Several species also grow in temperate regions. Importance Species of the ''Cynanchum'' genus had traditional Chinese medicinal uses. The root of ''Cynanchum atratum'' is used in Chinese traditional medicine and called ''Bai wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atropisomer
Atropisomers are stereoisomers arising because of hindered rotation about a covalent bond, single bond, where Gibbs free energy, energy differences due to steric strain or other contributors create a barrier to rotation that is high enough to allow for isolation of individual rotamers. They occur naturally and are of occasional importance in pharmaceutical design. When the substituents are achiral, these conformers are enantiomers (''atropoenantiomers''), showing axial chirality; otherwise they are diastereomers (''atropodiastereomers''). Etymology and history The word ''atropisomer'' (, , meaning "not to be turned") was coined in application to a theoretical concept by German biochemist Richard Kuhn for Karl Freudenberg's seminal ''Stereochemie'' volume in 1933. Atropisomerism was first experimentally detected in a tetra substituted biphenyl, a diacid, by George Christie and James Kenner in 1922. Michinori Ōki further refined the definition of atropisomers taking into account th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-dependent Density Functional Theory
Time-dependent density-functional theory (TDDFT) is a quantum mechanical theory used in physics and chemistry to investigate the properties and dynamics of many-body systems in the presence of time-dependent potentials, such as electric or magnetic fields. The effect of such fields on molecules and solids can be studied with TDDFT to extract features like excitation energies, frequency-dependent response properties, and photoabsorption spectra. TDDFT is an extension of density-functional theory (DFT), and the conceptual and computational foundations are analogous – to show that the (time-dependent) wave function is equivalent to the (time-dependent) electronic density, and then to derive the effective potential of a fictitious non-interacting system which returns the same density as any given interacting system. The issue of constructing such a system is more complex for TDDFT, most notably because the time-dependent effective potential at any given instant depends on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Phenols
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. As they are present in food consumed in human diets and in plants used in traditional medicine of several cultures, their role in human health and disease is a subject of research. Some phenols are germicidal and are used in formulating disinfectants. Classification Various Chemical classification, classification schemes can be applied. A commonly used scheme is based on the number of carbons and was devised by Jeffrey Harborne and Simmonds in 1964 and published in 1980: C6-C7-C6 Diarylheptanoids are not included in this Harborne classification. They can also be classified on the basis of their number of phenol groups. They can therefore be called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzophenones
Benzophenone is a naturally occurring organic compound with the formula (C6H5)2CO, generally abbreviated Ph2CO. Benzophenone has been found in some fungi, fruits and plants, including grapes. It is a white solid with a low melting point and rose-like odor that is soluble in organic solvents. Benzophenone is the simplest diaromatic ketone. It is a widely used building block in organic chemistry, being the parent diarylketone. History Carl Graebe of the University of Königsberg, in an early literature report from 1874, described working with benzophenone. Uses Benzophenone can be used as a photo initiator in ultraviolet (UV)-curing applications such as inks, imaging, and clear coatings in the printing industry. Benzophenone prevents UV light from damaging scents and colors in products such as perfumes and soaps. Benzophenone can also be added to plastic packaging as a UV blocker to prevent photo-degradation of the packaging polymers or its contents. Its use allows manufacture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic worms, and also objects such as wood splinters, distinguishing them from the organism's own healthy biological tissue, tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use humoral immunity, molecules and cell-mediated immunity, cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against bacteriophage, viral infections. Other basic immune mechanisms evolved in ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-aging Product
Anti-aging creams are predominantly moisturizer-based skin care products marketed with unproven claims of making the consumer look younger by reducing, masking or preventing signs of skin aging. Anti-aging supplements are ingestible products promoted to diminish the effects of aging, including vitamin supplements, powders, and teas. __TOC__ False health claims In the United States, anti-aging products are commonly marketed with false health claims, and are deemed to be among various scams on consumers. Since 2007, the US Food and Drug Administration (FDA) has issued dozens of warning letters to manufacturers of skin care products with false marketing including supposed anti-aging effects about the benefits of such products, which are not authorized to be marketed as drugs that would require FDA approval to be safe and effective for treating the aging process. Audience marketing Social media marketing has been effective at getting children and teenagers to buy anti-aging ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antioxidant
Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers, fuels, and lubricants, to extend their usable lifetimes. Foods are also treated with antioxidants to prevent Food spoilage, spoilage, in particular the rancidification of Vegetable oil, oils and fats. In Cell (biology), cells, antioxidants such as glutathione, mycothiol, or bacillithiol, and enzyme systems like superoxide dismutase, inhibit damage from oxidative stress. Known diet (nutrition), dietary antioxidants are vitamins vitamin A, A, vitamin C, C, and vitamin E, E, but the term has also been applied to various compounds that exhibit antioxidant properties in vitro, having little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-tumor
Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) in a standard regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs), or it may aim only to prolong life or to reduce symptoms ( palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called '' medical oncology''. The term ''chemotherapy'' now means the non-specific use of intracellular poisons to inhibit mitosis (cell division) or to induce DNA damage (so that DNA repair can augment chemotherapy). This meaning excludes the more-selective agents that block extracellular signals (signal transduction). Therapies with specific molecular or genetic targets, which inhibit growth-promoting signals from classic endocrine hormones (primarily est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traditional Chinese Medicine
Traditional Chinese medicine (TCM) is an alternative medicine, alternative medical practice drawn from traditional medicine in China. A large share of its claims are pseudoscientific, with the majority of treatments having no robust evidence of effectiveness or logical mechanism of action. Some TCM ingredients Traditional Chinese medicine#Safety, are known to be toxic and cause disease, including cancer. Medicine in traditional China encompassed a range of sometimes competing health and healing practices, folk beliefs, Scholar-official, literati theory and Confucianism, Confucian philosophy, Chinese herbology, herbal remedies, Chinese food therapy, food, diet, exercise, medical specializations, and schools of thought. TCM as it exists today has been described as a largely 20th century invention. In the early twentieth century, Chinese cultural and political modernizers worked to eliminate traditional practices as backward and unscientific. Traditional practitioners then selec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichroism
In optics, a dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colours) (not to be confused with Dispersion (optics), dispersion), or one in which light rays having different Polarization (waves), polarizations are absorbed by different amounts. In beam splitters The original meaning of ''dichroic'', from the Greek language, Greek ''dikhroos'', two-coloured, refers to any optical device which can split a beam of light into two beams with differing wavelengths. Such devices include mirrors and dichroic filter, filters, usually treated with optical coatings, which are designed to reflect light over a certain range of wavelengths and transmit light which is outside that range. An example is the dichroic prism, used in some camcorders, which uses several coatings to split light into red, green and blue components for recording on separate charge-coupled device, CCD arrays, however it is now more common to have a Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzophenone
Benzophenone is a naturally occurring organic compound with the formula (C6H5)2CO, generally abbreviated Ph2CO. Benzophenone has been found in some fungi, fruits and plants, including grapes. It is a white solid with a low melting point and rose-like odor that is soluble in organic solvents. Benzophenone is the simplest diaromatic ketone. It is a widely used building block in organic chemistry, being the parent diarylketone. History Carl Graebe of the University of Königsberg, in an early literature report from 1874, described working with benzophenone. Uses Benzophenone can be used as a photo initiator in ultraviolet (UV)-curing applications such as inks, imaging, and clear coatings in the printing industry. Benzophenone prevents UV light from damaging scents and colors in products such as perfumes and soaps. Benzophenone can also be added to plastic packaging as a UV blocker to prevent photo-degradation of the packaging polymers or its contents. Its use allows manufactur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
