Articles written in Proceedings – Section A
Volume 5 Issue 3 March 1937 pp 249-256
The methyl ethers of the
Volume 6 Issue 2 August 1937 pp 112-118
When umbelliferon condenses with malic acid two isomeric compounds are formed. The angular coumarino-7: 8-α-pyrone is the major product (95%) and its constitution is established from its preparation from umbelliferon-8-aldehyde by the Perkin's reaction. The second compound which should be the linear coumarino-7: 6-α-pyrone is formed in a very small yield only (5%). Under the same conditions 4-methylumbelliferon produces only one compound whose constitution as 4-methylcoumarino-7: 8-α-pyrone is arrived at from its independent synthesis from 4-methylumbelliferon-8-aldehyde. The constitution of this aldehyde is deduced not only from analogy but also from its reduction to 4: 8-dimethyl-7-hydroxycoumarin which has been prepared from 2-methylresorcinol and ethylacetoacetate. 4-Methylumbelliferon and ethylacetoacetate also give only one compound which is given the constitution 4: 4′-dimethylcoumarino-7: 8-α-pyrone. This compound has been found to be produced in good yield from resorcinol and ethylacetoacetate in the presence of alcoholic hydrogen chloride.
It is concluded that the angular isomer is the one invariably and most predominantly formed though the formation of the linear variety is not altogether precluded.
Volume 7 Issue 1 January 1938 pp 8-12
The behaviour of 7-hydroxy-coumarin indicates that there exists a double bond between 7 and 8 positions. But 7-hydroxy-4: 8-dimethyl-coumarin couples with diazocompounds and undergoes mercuration in the benzene nucleus. Its acetyl derivative undergoes the Fries migration and its allyl ether the Claisen transformation. It is therefore concluded that the nuclear double bonds are not fixed and are capable of assuming alternative positions.
Volume 7 Issue 4 April 1938 pp 296-303
Volume 7 Issue 5 May 1938 pp 312-318
The action of mercuric acetate on the methyl ethers of coumarinic and coumaric acids and their 5-nitro derivatives has been described. The first two undergo addition at the double bond as well as mercuration and the compounds have the carboxylic formula. The nitrocoumarinic and coumaric acids undergo addition only and yield the carboxylic form in the cold and the anhydro form on heating. When the addenda are eliminated by the action of dilute hydrochloric acid the change is accompanied by geometrical inversion from
Volume 8 Issue 4 October 1938 pp 214-219
The methylation of resacetophenone and its ω-methoxy derivative using methyl iodide and methyl alcoholic potash has been studied. The former gave 2-hydroxy-3-methyl-4-methoxyacetophenone the constitution of which was established by demethylation to 3-methylresacetophenone and comparison with a specimen prepared from 2-methylresorcinol. In the same way ω-methoxyresacetophenone gave 2-hydroxy-3-methyl-ω: 4-dimethoxyacetophenone which was subsequently converted to 3: 7-dimethoxy-8-methylflavone. The identity of this flavone was proved by its synthesis from 2-methyl-resorcinol.
It is concluded that under the above conditions resacetophenone undergoes nuclear methylation in the 3-position and that the hydroxyl group in the 4th position gets etherified.
Volume 8 Issue 4 October 1938 pp 220-222
Volume 9 Issue 1 January 1939 pp 1-6
7-Allyloxyflavone undergoes Claisen transformation to form 8-allyl-7-hydroxyflavone, the constitution of which is established from its synthesis from 3-allyl-resacetophenone. The bond distribution should therefore be as in (I). However 8-alkyl substituted derivatives undergo coupling with diazotised
Volume 9 Issue 1 January 1939 pp 7-9
Starting from 3-methoxy-7-hydroxyflavone, 2-methyl-3-methoxy-7-hydroxychromone and 7-hydroxyflavone aldehydes have been prepared. In these compounds the aldehyde groups occupy the eighth positions. By the action of sodium acetate and acetic anhyrdide the corresponding chromono-and flavono-α-pyrones have been synthesised.
Volume 9 Issue 2 February 1939 pp 133-135
The action of diazomethane on herbacetin yields 3∶7∶8∶4′-tetramethylherbacetin. The pentamethyl ether is obtained by the further methylation of the above tetramethyl compound with dimethyl sulphate and sodium hydroxide in aqueous acetone medium.
Volume 9 Issue 3 March 1939 pp 259-264
2-Methyl-3-methoxy-7-hydroxychromone-8-aldehyde formed a sodium derivative which readily condensed with bromoacetic ester to form the corresponding carbethoxy-methyl ether. This reaction did not take place satisfactorily with 3-methoxy-7-hydroxyflavone-aldehyde. The condensation was, however, smoothly effected in boiling benzene solution in the presence of potassium carbonate. When hydrolysed with aqueous potassium hydroxide, simultaneous ring-closure took place to yield 3-methoxyflavono-7: 8-furan-α-carboxylic acid which is considered to be karanjin-α-carboxylic acid.
Volume 9 Issue 4 April 1939 pp 328-332
Methylation of naringin by means of methyl iodide and potassium carbonate in acetone medium opens out the pyrone ring and methylates all the phenolic hydroxyl groups. The product on hydrolysis yields 2 ∶ 6 ∶ 4′-trimethoxy-4-hydroxychalkone. It is therefore concluded that in naringin the sugars, glucose and rhamnose exist as a disaccharide unit attached to position 7.
Volume 9 Issue 6 June 1939 pp 526-530
The formation of azo-dyes using one and more than two molecular proportions of diazotised
Volume 10 Issue 1 July 1939 pp 6-8
3-Benzoyl-7-hydroxyflavone has been prepared and its properties have been studied.
Volume 12 Issue 4 October 1940 pp 375-380
Volume 13 Issue 4 April 1941 pp 316-321
A number of umbelliferone derivatives with acetyl, benzoyl, carbethoxyl or carboxyl groups in the 3-position have been prepared of which 6 are new. The fluorescence exhibited by these has been studied and the results are discussed.
Volume 14 Issue 5 November 1941 pp 547-571
Volume 15 Issue 6 June 1942 pp 417-423
Pongamol, which is the second important crystalline component of the pongamia oil, has the molecular formula C18H14O4 and contains a methoxyl group. It has also a phenolic or enolic hydroxyl group. Demethylation with aluminium chloride yields nor-pongamol whereas treatment with hydriodic acid gives rise to a product which is probably isomeric but does not possess phenolic properties. Treatment with bromine produces a tetrabromo derivative which on boiling with acetone yields a tribromo compound. Oxidation with potassium permanganate or decomposition with alkali yields benzoic acid. From these properties and from colour reactions it is suggested that pongamol is a flavone derivative containing a hydroxyl, a methoxyl and an ethylene double bond.
Volume 16 Issue 1 July 1942 pp 10-15
The important citrus fruits (oranges) of the Northern Circars belong to three species: (1)
Volume 16 Issue 2 August 1942 pp 129-134
Employing a large number of natural and synthetic flavones, flavonols, flavanones and certain related compounds the scope of the following colour reactions has been examined: (1) reduction with magnesium and alcoholic hydrochloric acid, (2) reduction with sodium amalgam and alcohol and (3) Wilson’s boric acid test using boric and citric acid mixture in acetone solution. For the first two reactions the nature of the colour depends in general upon the number of hydroxyl or methoxyl groups in the molecule. In qualitative reactions it is not easily possible to effect minor distinctions between flavones, flavonols and flavanones. The boric acid test is very specific for 5-hydroxy- and 5-methoxyflavones and flavonols and
Volume 16 Issue 5 November 1942 pp 319-322
A crystalline compound melting at 197–8° and having the molecular formula C19H18O7 has been isolated from the roots of
Volume 17 Issue 1 January 1943 pp 20-25
By the oxidation of kanugin with potassium permanganate in acetone solution 4-o-methylresorcylic acid (I) and a neutral compound (II) containing methoxyl groups and having the formula C7H8O2 or C11H14O3 have been obtained. Hydrolysis with alcoholic alkali yielded an acid which seemed to be impure (I). The presence of a resorcinol unit in the molecule seemed to be thus established. Demethylation of kanugin gave rise to nor-kanugin. It had the properties of a flavonol (C16H12O7) and gave bright colours in alkaline buffer solutions. When its crystalline acetate was methylated a new methyl ether which was different from kanugin was produced. It was therefore concluded that by the action of hydriodic acid, besides demethylation some other changes were brought about.
Volume 18 Issue 3 September 1943 pp 171-178
A new method for the approximate colorimetric estimation of boric acid depending on the yellow colouration yielded by boric acid with pentamethyl-quercetin in presence of citric acid in anhydrous acetone medium has been described. The method is empirical in character and gives results with a maximum error of about 15% with quantities of boric acid ranging from 0·4 to 1·8 mg.
Volume 18 Issue 4 October 1943 pp 206-209
A sample of Indian ergot of the Nilgiris has been studied in detail. It contains remarkably high percentage of total and water-soluble alkaloids. With respect to other components it is normal.
Volume 19 Issue 1 January 1944 pp 14-16
The 5-hydroxycoumarins behave very similar to 7-hydroxycoumarins in regard to azo-dye formation with one and more than two molecular proportions of diazotised
The authors desire to express their grateful thanks to Prof. T. R. Seshadri for his kind interest in this work.
Volume 23 Issue 2 February 1946 pp 60-66
Kanugin C19H16O7 yields myristicic acid and
Volume 28 Issue 1 July 1948 pp 19-25
Volume 33 Issue 3 March 1951 pp 142-147
Chromic acid oxidation of teloschistin triacetate yields 4:5-diacetyl-7-
Volume 35 Issue 4 April 1952 pp 166-172
The isolation of three crystalline substances from the chloroform extract of the root bark of
Volume 38 Issue 1 July 1953 pp 13-19
The results obtained by a more detailed study of some of the amorphous fractions described in the previous communication on the root bark of
Volume 38 Issue 3 September 1953 pp 257-259
The pods of
Volume 44 Issue 5 November 1956 pp 279-283
Maxima substance A has been shown to be a dimethylenedioxy-iso-flavone. One of the methylenedioxy groups is in the 3′: 4′-position of the side phenyl nucleus; the other is most probably in the 6:7 position in the benzopyrone part.
Volume 46 Issue 3 September 1957 pp 245-249
The leaves of
Volume 49 Issue 4 April 1959 pp 241-249
The constitution of the pigment isolated from the seeds of
Volume 50 Issue 3 September 1959 pp 167-174
The crystalline substance obtained from the seeds of
A number of derivatives and degradation products have been prepared and analysed.
Volume 50 Issue 4 October 1959 pp 289-289 Erratum
Volume 50 Issue 6 December 1959 pp 366-373
The examination of the leaves of
Volume 51 Issue 6 June 1960 pp 322-327
The flowers of
Volume 52 Issue 4 October 1960 pp 173-181
The chemical examination of the bark of
Volume 53 Issue 2 February 1961 pp 98-104
The chemical examination of the leaves
Volume 54 Issue 1 July 1961 pp 51-59
Volume 54 Issue 2 August 1961 pp 99-104
The examination of the leaves of
Volume 54 Issue 3 September 1961 pp 132-139
Experiments leading to the establishment of the constitution of campanulin are described and discussed.
Volume 54 Issue 6 December 1961 pp 345-351
The constitution of ruvoside, a new glycoside from
Volume 56 Issue 5 November 1962 pp 239-241
The leaves of
Volume 57 Issue 2 February 1963 pp 88-93
The identity of tora substance C with rubrofusarin and of tora substance B with nor-rubrofusarin has been established.
Volume 57 Issue 2 February 1963 pp 115-120
The bark of
Volume 57 Issue 3 March 1963 pp 135-141
Reactions and degradations leading to the constitution of maxima substance B as 7-0-
Volume 62 Issue 4 October 1965 pp 224-230
The leaves of
Volume 64 Issue 3 September 1966 pp 185-191
Taxifolin (a dihydro flavonol) and a procyanidin have been isolated from the stem bark of