- Chlorometabolite production by the ecologically important white rot fungus Bjerkandera adusta
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Two strains of the basidiomycete, Bjerkandera adusta (DAOM 215869 and BOS55) produce in static liquid culture, phenyl, veratryl, anisyl and chloroanisyl metabolites (CAM's) (alcohols, acids and aldehydes) as well as a series of compounds not previously known to be produced by Bjerkandera species: 1-phenyl, 1-anisyl, 1-(3-chloro-4-methoxy) and 1-(3,5-dichloro-4-methoxy) propan-1,2-diols, predominantly as erythro diastereomers with 1R, 2S absolute configurations. 1-Anisyl-propan-1,2-diol and 1-(3,5-dichloro-4-methoxy)-propan-1,2-diol are new metabolites for which the names Bjerkanderol A and B, respectively, are proposed. Experiments with static liquid cultures supplied with 13C66- and 13C9-L-phenylalanine showed that all identified aromatic compounds (with the exception of phenol) can be derived from L-phenylalanine. For the aryl propane diols, the 13C label appeared only in the phenyl ring and the benzylic carbon, suggesting a stereoselective re-synthesis from a C7 and a C2-unit, likely aromatic aldehyde and decarboxylated pyruvate, respectively. Other compounds newly discovered to be derived from phenylalanine by this white rot fungus include phenylacetaldehyde and phenylpyruvic, phenylacetic, phenyllactic, mandelic and phenyl glyoxylic (benzoyl formic) acids. For both strains, cultures supplied with Na37Cl showed incorporation of 37Cl in all identified chlorometabolites. Veratryl alcohol and the CAM alcohols, which occur in both strains and can be derived from L-phenylalanine (all 13C-labelled), have reported important physiological functions in this white rot fungus. Possible mechanisms for their formation through the newly discovered compounds are discussed.
- Silk,Aubry,Lonergan,Macaulay
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- Banana-shaped liquid crystals based on 2,7-dihydroxynaphthalene derivatives
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Abstract New mono- and dichloro-substituted derivatives of 2,7-dihydroxynaphthalene were synthesized, and their mesomorphic properties were investigated. Bis-2,7-[4-(4-n-alkoxybenzoyloxy)-3-chlorobenzoyloxy]-naphthalenes with the terminal nonyloxy or decyloxy group were found to form nematic and B1 mesophases; the homolog with dodecyloxy group formed B2 modification exclusively. Bis-2,7-[4-(4-n-alkoxybenzoyloxy)-3,5-dichlorobenzoyloxy]naphthalenes occurred to be non-mesomorphic and vitrified from isotropic liquid.
- Derkach,Novikova,Gorecka
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- Proton mobility in 2-substituted 1,3-dichlorobenzenes: "ortho" or "meta" metalation?
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Nine 1,3-dichlorobenzene congeners were selected as model compounds to assess the relative rates of proton abstraction from 4- and 5-positions ("ortho" vs. "meta" metalation). Using lithium 2,2,6,6-tetramethylpiperidide as the basic reagent, the chlorine-adjacent 4-position underwent metalation exclusively. In contrast, attack at the chlorine-remote 5-posi" tion became significant even in the case of moderately sized 2-substituents (such as dimethylamino or ethyl) when secbutyllithium was employed. The "ortho/para" (4-/5-) ratios ranged from 80:20 to 65:35. The more pronounced "meta-orienting" effect of silicon as opposed to carbon substituents can be attributed to dissimilarities in the n polarization of the aromatic ring. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Schlosser, Manfred,Heiss, Christophe,Marzi, Elena,Scopelliti, Rosario
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p. 4398 - 4404
(2007/10/03)
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- Oxidative chlorination, desulphonation, or decarboxylation to synthesize pharmaceutical intermediates: 2,6-Dichlorotoluene, 2,6-dichloroaniline, and 2,6-dichlorophenol
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An alternative manufacturing process scheme was developed for 2,6-dichlorotoluene, 2,6-dichloroaniline, and 2,6-dichlorophenol, involving oxidative chlorination after protection of the starting material in the para position followed by deprotection involving desulphonation or decarboxylation. Oxidative chlorination of 4-methylbenzenesulphonic acid, 4-methylbenzoic acid, 4-aminobenzoic acid, and 4-hydroxybenzoic acid by using HCl-H2O2, and their subsequent desulphonation or decarboxylation, gave a 60-75% yield of the desired product.
- Mukhopadhyay,Chandalia
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- PHOTOREACTION OF BENZOIC ACID WITH SODIUM HYPOCHLORITE IN AQUEOUS ALKALI
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The photoreaction of benzoic acid with sodium hypochlorite in aqueous alkali (pH > 12) has been studied.At a low initial ratio of , e.g, 0.1, hydroxylation and chlorination at the aromatic ring occur simultaneously with ipso-substitution of the carboxylate group to give hydroxy- and chlorobenzoic acids together with phenol.The product distribution depends on the wavelength of the light, which implies the dependence on the concentration of avtive species generated from ClO(1-) and on the light stability of products.At comparable concentrations of ClO(1-) and PhCOO(1-), the products initially formed from the photoreaction react further with ClO(1-) in the dark to give polychlorinated derivatives.The initial steps for the photoreaction are discussed on the basis of the reactivity of the active species, O(3P), O(1D), O(1-)(.), and Cl(.), generated by photolysis of ClO(1-).
- Ogata, Yoshiro,Tomizawa, Kohtaro
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p. 985 - 988
(2007/10/02)
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