Pulvinic acids

The tropical fungus Scleroderma sinnamariense has afforded methyl 2, 5 -dichloro-4,4 -di-0-methylatromentate (2196) (1979), and the related pulvinic acid derivative methyl 3, 5,-dichloro-4.4 -di-0-methylatromentate (2197) was isolated from the fruiting body of a Scleroderma sp. ( poison puff ball ) (1980). A New Zealand Chamonixia pachydermis has yielded pachydermin (2198) (1981). 

Arnold N, Steglich W, Besl H (1996) Derivatives of Pulvinic Acid in the Genus Scleroderma. Z Mykol 62 69... 

Simple alkylated polyhydroxyterphenyls like penioflavin (114), isolated from Peniophora sanguinea, can be derived formally from a C-18 terphenylquinone as precursor and subsequent formation of a new carbon-carbon bond [94]. The biosynthesis of xylerithrin (118) and related pigments from P. sanguinea, according to the studies of Von Massow [113, 114], requires the insertion of a third unbranched phenylpropanoid unity on a pulvinic acid intermediate derived from a terphenylquinone, as indicated in Scheme 2. 

Polyporic acid (1) is converted in 95 % yield into pulvinic acid dilactone (2) on... 

Tryptophan and its relative indolylpyruvic acid (3.42) have been shown to precursors of hinnuliquinone (3.41), which is a pigment of Nodulisporium hin-nuleum. Typical of many fungal indoles in which alkylation by a dimethylallyl or isopentenyl group has occurred, mevalonate was also a precursor. However, the stage at which prenylation of a monomer or a dimer took place was unclear. Asterriquinone (3.43) from Aspergillus terreus and cochliodinol (3.44) from Chaetomium cochliodes are similar metabolites. Fission of the hydroxyquinone in the latter followed by lactonization leads to cochliodinone (3.45) in a sequence that is similar to that which inter-relates the terphenyls and pulvinic acids described in Chapter 7. 

Cleavage of the hydroxyquinone ring system and relactonization affords another series of pigments known as the pulvinic acids, which may be exemplified by gomphidic acid (7.23). The dry-rot fungus, Serpula lacrimans, produces xerocomorubin (7.24), which is another example. These pulvinic acid moieties form part of a complex group of metabolites known as the badiones. They are... 

Apart from the A-methylated compound,1 examples for derivatives of the fully conjugated pyridazino[4,3-c]pyridazine or the unsubstituted compound 1 itself are not known. Attempts to synthesize 4,8-diphenylpyridazino[4,3-c]pyridazine-3,7-diol (3) by reacting pulvinic acid lactone 2 with an excess of hydrazine failed, instead 6-benzyl-4-phenylpyridazine-3,5-diol (4) was produced. The reaction is thought to proceed via the attack of hydrazine on one lactone ring and water on the other, followed by decarboxylation.4... 

Screening pigments Pulvinic dilactone Pulvinic acid derivative 1672 1405 >246 290 367 431 422... 

Tetronic Acids. - An improved route to (E)- (and (Z)-) pulvinic acids... 

Olefination reactions of the phosphonates (254) and (255) derived from hydantoin and 1-methylhydantoin, respectively, provide good yields of the expected C-5 unsaturated hydantoin derivatives (256), generally as mixtures of isomers. 52 Heterocyclic analogues, e.g. (257), of pulvinones and, e.g. (258), of permethylated pulvinic acids have been synthesized by Wadsworth-Emmons reactions of the phosphonates (259) and (260), themselves prepared directly from substituted maleic anhydrides. 55 The reaction of ylide (261) with aldehydes to give (262) has been used as a key... 

Patenden et al. [46] synthesized heterocyclic analogues of pulvinones 52-55 and of permethylated pulvinic acids 56, 57 which were found in higher fungi (Scheme 21). All compounds possessing lactonic structures were synthesized in the Horner-Wittig reaction using the corresponding heteroaryl aldehydes and 4-dimethoxy-phosphorylated lactone 58. The latter was obtained as the main product in the reaction between substituted maleic anhydrides 59 and sodium dimethyl phosphite via the postulated carbene. 

Potassium hydroxide, 20, 239, 303-304 Potassium persulfate, 274 Potassium superoxide, 304-307 Potassium tri-sec-butylborohydride, 307 Prins reaction, 159 Progesterone, 107 Proline, 10, 307 1,3-Propanediol, 37 Propargylic alcohols, 8, 53 Propargylic chlorides, 155 (E)-Propenyllithium, 141 Propiolaldehyde diethyl acetal, 79-80 Propiolamidium salts, 124 Fropiolate esters, 8 Propiolic add, 295 Propylene carbonate, 74 Propylene oxide, 74 Protolichesterinic add, 412 Pterocarpins, 114 Pulegone, 287, 288, 308-309 tosylhydrazones, 375-376 Pulvinic acid pigments, 291 Pumiliotoxin, 28... 

Dehydration. British chemists have developed a total synthesis of un-symmetrical pulvinic acid pigments of lichens and fungi. The method is illustrated for the synthesis of the permethylated derivative of gomphidic acid (4), the... 

C (decomp.). A pulvinic acid derivative from the mushroom Gomphidius glutinosus (Basidio-mycetes). Together with xerocomic acid G. is responsible for the yellow color of the stem base. 

The G. are easily recognized by their violet color reaction with concentrated sulfuric acid and are thus distinguished from pulvinic acids. The G. in fungi are formed by condensation of 2 molecules of 4-hydroxy-phenylpyruvic acid and subsequent hydroxylation steps (see also terphenylquinones). 

C15H14O5, Mr 322.32, yellow cryst., mp. 148-149°C (other reports 145-146 °C), soluble in chloroform. A typical lichen acid, e. g., in Letharia vulpina. V. a. also occurs in some mushrooms of the order Boletales. Saponification of V. a. affords pulvinic acid (see also gomphidic acid, xerocomic acid). V. a. has antibacterial as well as antiviral activities and inhibits the growth of plants. V. a. is used in some countries as a natural dye for wool. ... 

Dilactones. Polyporic acid allowed to react 15 min. at 60° with a 1 2 mixture of acetic anhydride and dimethyl sulfoxide pulvinic acid dilactone. Y 90%. F. e. with monohydroxyquinones s. H. W. Moore and R. J. Wikholm, Tetrah. Let. 1968, 5049. 

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