Proceedings of the Indian Academy of Sciences - Section A

Solanki, D.; Kamath, I.

doi: 10.1007/BF03171065pmid: N/A

The optimum conditions for the electro-chemical formation of sodium persulphate from aqueous sodium sulphate have been investigated with respect to the bath, composition, anodic and cathodic current densities, interelectrode distance, temperature, duration of the electrolysis, current concentration, the influence of “addition agents” and the use of a diaphragm. A strongly acidic bath favours the reaction. At the optimum temperature.viz., 10°C. high anodic current densities up to 82·2 amps./dm2 are advantageous. The process is complicated by the fact that after about 2 amp. hours the persalt tends to separate as a solid phase. Our results do not support Muller’s hypothesis of a ‘steady state’ in the corresponding sulphuric acid electrolysis. A current efficiency as high as 92·7% has been obtained with a diaphragm, HF as ‘addition agent’ and special concentration (vide infra) of the bath solution.

Rajagopalan, C.

doi: 10.1007/BF03171066pmid: N/A

Desai, R.; Waraydekar, W.

doi: 10.1007/BF03171067pmid: N/A

Two methods for the preparation of 4-stearyl, 4-palmityl and 4-lauryl-1-naphthols have been worked out. One did not give the desired product but its intermediate compounds have been studied. The other method gave fairly good yields but not quite satisfactory.

Desai, R.; Waravdekar, W.

doi: 10.1007/BF03171068pmid: N/A

4-Stearyl, 4-palmityl, and 4-lauryl-1-naphthols were prepared in fairly good yield by the action of their respective acid chlorides on α-naphthol. Their properties have been studied, and compared with those of 4-acetyl-1-naphthol.

Rao, N.; Seshadri, T.

doi: 10.1007/BF03171069pmid: N/A

Detailed chemical examination of the roots ofD. ferruginea has now been carried out. Of the two varieties, the rotenone-free one is further characterised by not giving any crystalline component. The rotenonebearing variety yields besides rotenone (4·3%), only a small amount of dehydro-rotenone. The chemical chaaracteristics of rotenone-bearingD. ferruginea andD. elliptica are compared. It seems to be possible to use chemical composition to distinguish one from the other.

Seshadri, T.; Venkateswarlu, V.

doi: 10.1007/BF03171070pmid: N/A

By the condensation of 2-hydroxy-ω: 3∶4∶5∶6-pentamethoxy-acetophenone with the anhydride and potassium salt ofp-benzoyloxy-benzoic acid is obtained 4′-hydroxy-3∶5∶6∶7∶8-pentamethoxy-flavone which yields calycopterin by partial demethylation using hydrobromic acid.

Rao, K.; Seshadri, T.

doi: 10.1007/BF03171071pmid: N/A

The colouring matter of the flower petals ofHibiscus vitifolius consists almost entirely of gossypin along with very small amounts of quercetin. These petals form a very good source of this new and interesting glycoside and eventually of gossypetin also.

Krishnamurti, G.; Seshadri, T.

doi: 10.1007/BF03171072pmid: N/A

Phyllanthin, the bitter principle of the leaves ofPhyllanthus niruri has been isolated in a crystalline condition and in good yield. It melts at 97–98°, has the molecular formula C21H22O7 and contains methoxyl and methylene-dioxy groups. Its important properties are described. A related crystalline substance, hypophyllanthin, which is not bitter, has also been isolated in a small yield. The leaves contain about 5% of wax which consists mostly of esters.

Rao, N.; Seshadri, T.

doi: 10.1007/BF03171073pmid: N/A

The roots ofDerris scandens obtained from the Central Provinces of India have now been investigated in detail. From the chloroform extractives (7·0%) three crystalline substances could be isolated and characterised. There is no rotenone. The major component is scandenin, as in the case of the American sample examined by Clark; but the yield is much higher. The other two substances appear to be new compounds and are therefore named ‘Nallanin’ and ‘Chandanin’. Lonchocarpic and robustic acids are not found in the Indian roots.

Rao, K.; Seshadri, T.

doi: 10.1007/BF03171074pmid: N/A

The analytical data indicate that gossypin is a monoglucoside. As a result of complete methylation and hydrolysis it yields an O-pentamethyl gossypetin. From a study of its decomposition with alcoholic potash whereby veratric acid is obtained and from a comparison of its properties with those of isomeric compounds, it is concluded that it has a free hydroxyl in the 8-position. Consequently gossypin should be 8-monoglucoside of gossypetin. The synthesis of O-pentamethyl gossypetin with a hydroxyl in the 3-position has been described.