P-methoxybenzoic Acid Research Articles

An X-ray study of the p-n-alkoxybenzoic acids. Part IV. Crystal structure of p-n-butoxybenzoic acid

The crystal structure of the title compound has been determined from 740 reflections measured by diffractometer. Crystals are monoclinic, a= 27.148(4), b= 4.013(1), c= 21.787(3)A, β= 135.97(1)°, space group C2/c, Z= 8. The structure was solved by a fit of the weighted reciprocal lattice to the calculated Fourier transform for the molecule, and refined by block-diagonal least-squares to R 0.053.The carboxy-group seems to be disordered by 180° rotation about the C–C bond joining it to the phenyl ring. The structure, including small deviations from overall planarity, is similar to that of p-methoxybenzoic acid. Molecules exist as centrosymmetric hydrogen-bonded dimers [O ⋯ O 2.600(3)A] the packing being similar to that of anisic acid, but significantly different from that of higher homologues.

PHENYLPROPAN–DERIVATE AUS DEM ÄTHERISCHEN ÖL VONLIMNOPHILA RUGOSA

The essential oil from the fresh leaves of Limnophila rugosa (Roth) Merrill (Scrophulariaceae), from the plants raised in Kumaon (Uttar Pradesh, India) has been examined for its chemical composition by Chromatographie, N. M. R., I. R., U. V. andM. S. techniques. The presence of p-methoxy benzoic acid, anisaldehyde, anethole, estragole, other unidentified phenylpropane derivatives and one unknown tricyclic sesquiterpene (Ci 5 H M ) has been confirmed.

Degradation of Methoxylated Benzoic Acids by a Nocardia from a Lignin-Rich Environment: Significance to Lignin Degradation and Effect of Chloro Substituents

Strain A81 of Nocardia corallina hydroxylates or demethylates p-anisic acid to p-hydroxybenzoic acid and isovanillic acid. It demethylates veratric acid to a mixture of vanillic and isovanillic acids. These are both demethylated to protocatechuic acid, which undergoes ring cleavage to afford beta-carboxy-cis-cis-muconic acid. The intermediacy of protocatechuic acid in the catabolic pathway of veratric acid was confirmed by blocking ring cleavage with an additional substituent in the ring: 5-chlorovanillic acid was demethylated to 5-chloro-protocatechuic acid, which accumulated. Chloro substituents in the ring of other methoxylated benzoic acids also arrested their normal metabolism by the Nocardia: an ortho-chloro substituent thwarted both demethylation and ring-opening. ortho-Hydroxylation of p-methoxybenzoic acid to isovanillic acid was unaffected by a chlorine ortho to the methoxyl group. Washed whole cells of veratric acid-grown N. corallina A81 produced no detected structural changes in an isolated lignin. The implications of this observation are discussed.

Metabolism of alkenebenzene derivatives in the rat. I. p-Methoxyallylbenzene (Estragole) and p-methoxypropenylbenzene (Anethole).

Abstract1. The metabolism of p-methoxyallylbenzene (estragole) and p-methoxy-propenylbenzene (anethole) in the rat has been investigated. The metabolites were identified and quantitatively determined mainly by g.l.c. and by combined g.l.c.-mass spectrometry.2. The major metabolic reactions of p-methoxyallylbenzene were found to be O-demethylation to p-hydroxyallylbenzene and oxidation of the allylic side chain to p-hydroxy-3-(p-methoxyphenyl)propionic acid or to p-methoxybenzoic acid (anisic acid) which was largely excreted as p-methoxyhippuric acid. The former oxidative pathway involved epoxidation of the double bond and subsequent hydration to the diol whereas the latter pathway involved migration of the double bond and the formation of cinnamoyl intermediates. Other reactions gave rise to 1-(p-methoxyphenyl)allyl alcohol and to p-methoxyphenylacetic acid and its glycine conjugate. A total of at least 60–65% but as much as 90% dose was accounted for.3. A major metabolic reaction of p-methoxypropenylbenz...

Bacterial degradation of p-methoxybenzoic acid.

A cell-free system from a Pseudomonas sp., strain PM3, catalysed the oxidative demethylation, hydroxylation and subsequent ring cleavage of p-methoxybenzoate. Demethylation, to yield p-hydroxybenzoate, involved absorption of 1.0 mole of oxygen/mole of p-methoxybenzoate, and required reduced pyridine nucleotide (either NADH or NADPH) as cofactor. p-Hydroxybenzoate was hydroxylated to yield protocatechuate with the absorption of 1 mole of oxygen/mole of substrate, and required NADPH as cofactor. Protocatechuate was oxidized, with absorption of 1 mole of oxygen/mole of substrate, to 3-oxoadipate. The methyl group of p-methoxybenzoate was removed as formaldehyde, and oxidized to formate and carbon dioxide by formaldehyde dehydrogenase, which required GSH and NAD+, and formate dehydrogenase, which required NAD+.

An X-ray study of the p-n-alkoxybenzoic acids. Part II. The crystal structure of anisic acid

A three-dimensional X-ray study has been made of the crystal structure of anisic acid (p-methoxybenzoic acid). Crystals are monoclinic, a= 16·98 ± 0·03, b= 10·95 ± 0·02, c= 3·98 ± 0·01 A, β= 98° 40′± 10′, space-group P21/a, Z= 4. The analysis was based on 687 reflections measured, with Mo-K radiation and balanced filters, by scintillation counting. Atomic co-ordinates obtained in a previous two-dimensional analysis were used as a starting point and the structure refined by Fourier, difference Fourier, and least-squares methods to a final R of 0·082.Seven of the eight hydrogen atoms were located and anisotropic thermal parameters were used for the heavy atoms. The molecule is distorted from a planar configuration by intermolecular stresses. Thus, although the carbon atoms of the phenyl ring and the attached oxygen atom are strictly coplanar the atoms of the carboxyl group and the methyl carbon atom are displaced from this plane by between 0·05 and 0·16 A. In addition, intramolecular stresses between the methyl-hydrogen atoms and the hydrogen atom adjacent in the ring make the C–C–O angles at the point of attachment of the methoxy-group unequal, 114 and 126°. Within the ring the C–C bond distances lie in the range 1·379–1·396 A, and the extra-ring C–C bond is 1·502 A. The e.s.d.s. in these distances are 0·009 A. Other distances are: C–OH, 1·290 A; CO, 1·233 A; C–O, 1·360 A; and O–CH3, 1·443 A, with e.s.d.s of 0·008 A. Angles in the ring lie between 118·9 and 121·2°. Around the carboxyl group, O–C–O = 123·4°, C–CO = 119·1°, and C–C–OH = 117·5°. At the methoxyl oxygen atom, C–O–C = 116·8°. In the crystal the molecules form hydrogen-bonded dimers, O–H ⋯ O = 2·643 A, and these dimers are intermeshed closely, in the region of the O–H ⋯ O linkages with the methyl groups of neighbouring molecules. It is suggested that this feature prevents the two lowest members of the series from forming liquid crystals but that a similar interleaving of molecules is needed to cause the higher homologues to show such behaviour.

Pheromones of the Honeybee: Chemical Studies of the Mandibular Gland Secretion of the Queen

SUMMARYPhysical and chemical investigations of extracts of the heads of queen honeybees have been made with the object of identifying the components of the mandibular gland contents. By gas-liquid chromatographic examination the following have been identified: methyl 9-oxodecanoate, methyl 9-oxodec-2- enoate, methyl 9-hydroxydecanoate, methyl 9-hydroxydec-2-enoate, methyl p-hydroxybenzoate, nonoic acid, decanoic acid, dec-2-enoic acid, 9-oxodecanoic acid, 9-hydroxydecanoic acid, 9-oxodec-2-enoic acid, 9-hydroxydec-2-enoic acid, lO-hydroxydec-2-enoic acid and p-methoxybenzoic acid. The chromatographic traces also indicate the presence of an additional substance in the neutral fraction and seventeen as yet unidentified substances in the acid fraction.

The influence of trace elements on the metabolism of aromatic compounds by soil fungi.

SUMMARY: The effect of copper, iron, manganese and zinc on the metabolism of catechol, o-, m- and p-hydroxybenzoic, o-, m- and p-methoxybenzoic, 3:4-dimethoxybenzoic and vanillic acids was investigated. Aspergillus niger, Hormodendrum sp. and Penicillium sp. mycelia which were deficient in the various trace elements were the organisms used. Only iron had any marked effect on the rates of metabolism and on the accumulation of intermediate products of metabolism in the substrate solutions. The intermediate products identified were: protocatechuic acid from m- and p-hydroxybenzoic and p-methoxybenzoic acids; catechol from o -hydroxy- benzoic acid; vanillic acid from 3:4-dimethoxybenzoic acid; o-, m- and p-hydroxy- benzoic acids from the corresponding mono-methoxybenzoic acids.

Metabolism of methoxylated aromatic compounds by soil fungi.

SUMMARY: The metabolism of methoxylated aromatic compounds by the soil fungi Haplographium sp., Hormodendrum sp. and Penicillium sp. has been investigated. A study of rates of decomposition of mono-methoxybenzoic acids by Hormo-dendrum sp. revealed that they are most rapidly attacked in the order para (p). meta (m) and ortho (o). In respiration studies with all three fungi the p form was again found to be metabolized most rapidly. In the initial stage of attack the methoxyl group is replaced by a hydroxyl group. Penicillium sp. also formed p-methoxyphenol from p-methoxyhenzoic acid. A study of the rates of metabolism of monohydroxy-benzoic acids revealed that they are attacked in the same order as the monometh-oxybenzoic acids. p-Hydroxybenzoc acid formed from p-methoxybenzoic acid is further metabolized to protoetechuic acid by Hormodendrum sp. and Pencillium sp. When veratric acid (3:4-dimethoxybenzoic acid) is incubated with Hormodendrum sp. and Penicillium sp. the methoxyl group in the p position is replaced by a hydroxyl group to give vanille acid. All three fungi formed two unidentified phenolic compounds from 2:4-dimethoxybenzoic acid. The possible significance of the results in the decomposition of lignin in soil is discussed.

The Effects of Paba Derivatives on the Multiplication of Typhus Rickettsiae

Summary and Conclusions The rickettsiostatic activity of 1) isosteres of PABA, 2) p-halobenzoic acids, 3) p-alkoxybenzoic acids and 4) compounds with substitutions in the carboxyl group of PABA were determined. The compounds were titrated to an upper limit which was toxic to the embryo or inhibitory to the growth of rickettsiae and to a lower limit which was non-inhibitory to the growth of rick-ettsiae. PABA and its isosteres showed the following order of activity: p-aminobenzoic acid τ; p-methylbenzoic acid τ; p-fluorobenzoic acid. p-Hydroxybenzoic acid did not exhibit rickettsiostatic activity. The order of rickettsiostatic activity of the p-halobenzoic acids was: p-iodobenzoic acid τ; p-bromobenzoic acid τ; p-chlorobenzoic acid τ; p-fluorobenzoic acid. The rickettsiostatic activity of the effective p-alkoxybenzoic acids increased directly as the length of the carbon chain: p-pentoxy benzoic acid τ; p-propoxybenzoic acid τ; p-ethoxybenzoic acid τ; p-methoxybenzoic acid. p-Butoxy-benzoic acid was not active. p-Aminohippuric acid partially inhibited the growth of rickettsiae. Other compounds containing carboxyl group substitutions (p-aminoacetophenone and p-aminopropiophenone, and methyl-p-aminobenzoate) were very toxic to the embryos and did not inhibit rickettsiostatic activity when given in tolerated doses.

CXCVII.—The nitro- and amino-derivatives of o- and p-methoxybenzoic acids and of α- and β-methoxynaphthoic acids

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