instance_of guibourtinidin
Anthocyanins ( also anthocyans ; from Greek : " ( anthos )" = ___MASK87___ + " ( kyanos )" = blue ) are ___MASK26___ - soluble vacuolar pigments that ___MASK81___ appear red , purple , or blue depending on the pH . They belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway ; they are odorless but flavorful , contributing to taste as a moderately astringent sensation . Anthocyanins occur in all tissues of higher plants , including leaves , stems , roots , flowers , and fruits . Anthoxanthins are clear , white to yellow counterparts of anthocyanins occurring in plants . Anthocyanins are derived from anthocyanidins by adding sugars . A counterion ( pronounced as ___MASK89___ words , i . e . " counter " " ion ", and sometimes written as ___MASK89___ words ) is the ion that accompanies an ionic ___MASK61___ in order to maintain electric neutrality . In table salt ( NaCl ), the sodium ___MASK22___ is the counterion for the chlorine anion and vice versa . The ___MASK3___ ion is the anion ( negatively charged ion ) Cl . It is formed when the element chlorine ( a halogen ) gains an electron or when a compound such as hydrogen ___MASK3___ is dissolved in ___MASK26___ or other polar solvents . Chloride salts such as sodium ___MASK3___ are often very soluble in ___MASK26___ . It is an essential electrolyte located in all body fluids responsible for maintaining acid / ___MASK97___ balance , transmitting nerve impulses and regulating fluid in and out of cells . Less frequently , the word " ___MASK3___ " ___MASK81___ also form part of the " common " name of chemical compounds in which one or more chlorine atoms are covalently bonded . For example , methyl ___MASK3___ , with the standard name chloromethane ( see IUPAC books ) is an organic compound with a covalent C  Cl bond in which the chlorine is not an anion . In organic chemistry and biochemistry , a substituent is an atom or ___MASK59___ of atoms which replaces ___MASK67___ atom on the parent ___MASK4___ of a hydrocarbon , becoming a moiety of the resultant new ___MASK69___ . The terms substituent , side ___MASK4___ , ___MASK59___ , branch , or pendant ___MASK59___ are used almost interchangeably to describe branches from a parent structure , though certain distinctions are made in the context of ___MASK63___ chemistry . In polymers , side chains extend from a backbone structure . In proteins , side chains are attached to the alpha carbon atoms of the amino acid backbone . In chemistry , an oxonium ___MASK8___ is any oxygen ___MASK22___ with three bonds . The simplest oxonium ___MASK8___ is the hydronium ___MASK8___ HO . Another class of oxonium ions frequently encountered in organic chemistry is the oxocarbenium ions , obtained by protonation or alkylation of a carbonyl group e . g . R  C = O  R  which forms a resonance structure with the fully - fledged carbocation R  C  O  R  and is therefore especially stable : Guibourtinidin is a anthocyanidin . Polymethines are compounds made up from an " odd " ___MASK10___ of methine groups ( CH ) bound together by alternating ___MASK65___ and double bonds . Compounds made up from an " even " ___MASK10___ of methine groups are known as polyenes . Anthocyanidins are common ___MASK93___ pigments . They are the sugar - free counterparts of anthocyanins based on the flavylium ion or 2 - phenylchromenylium , which is a type of oxonium ion ( chromenylium is referred also to as benzopyrylium ). They form a large group of polymethine ___MASK74___ . In particular anthocyanidins are salt derivatives of the 2 - phenylchromenylium ___MASK22___ , also known as flavylium ___MASK22___ . As shown in the figure below , the phenyl group at the 2 - position can carry different substituents . The counterion of the flavylium ___MASK22___ is mostly chloride . With this positive charge , the anthocyanidins differ from other flavonoids .