A detailed chemical examination of the Indian senna leaves has been made. The ash has been analysed. An aqueous extract of the leaves has been found to contain a good amount of calcium salts. A petroleum ether extract yields senna wax consisting of free myricyl alcohol admixed with regular wax. Methods have been worked out for obtaining the flavonol and authraqui one group of compounds separately in the most convenient manner and in the best yield. The flavonol portion consists of iso-rhamnetin and kæmpferol in more or less equal quantities, whereas the anthraquinone portion contains mostly rhein along with small quantities of emodin.

A colourless wax has been isolated from the flowers ofButea frondosa and its physical and chemical properties are described. The unsaponifiable matter consists mainly of myricyl alcohol along with small quantities of steroids. The composition of the saturated fatty acid mixture is very similar to that found in the seed oil.

A new method of isolating butein and butin from the flowers ofButea frondosa is described. The total yield of the aglucones is 0.34% on the weight of the air-dry flowers. By separating them using boiling water, it has been found that butein exists to the extent of 0.3% and butin 0.04%.

The conditions for the production of paper pulp from rice straw by the alkali process have been investigated. About 22% of soda on the weight of the straw used in 3% solution, a temperature of 100–05°C. and a cooking period of 3 hours have been found to be satisfactory. With a view to effect economy in alkali the mother liquor has been used in a subsequent double boiling process yielding paper pulp of good quality. In a straw having cellulose (Cross and Bevan) 37·5% the yield of paper pulp is about 44%. The characteristics of the pulp are described in detail.

The general chemical composition of the roots ofDecalepis Hamiltonii has been studied. The petroleum ether extract of the Decalepis roots was found to contain (1) a ketonic substance melting at 83–84°, resinol fractions melting between 130 and 185°, a definite compound of the same group melting at 235–36°, sterols and para methoxysalicylicaldehyde. The subsequent alcohol extract contained besides saponins and tannins a crystalline resin acid melting at 245°, an amorphous resin acid melting at 180° and inactive inositol.

Butrin has been obtained by a simple method and in good yield from the flowers ofButea frondosa. On hydrolysis with acids it gives a mixture of butin and butein. Two colourless crystalline compounds have also been isolated, one of which is a phytosterolin and the other an unidentified heteroside.

The roots of theHemidesmus indicus were studied on the lines adopted forDecalepis Hamiltonii and were found to have a similar composition particularly with regard to the petrol extract. Since theDecalepis roots contain much higher percentages of the various chemical components they are more suitable for use as drug.

The existence of resinol in the petrol-soluble portions ofDecalepis Hamiltonii andHemidesmus indicus has been established by the isolation of α- and β-amyrins and lupeol from them. They exist both free and as esters. The various fractions have been analysed using both the acetate and the benzoate methods. The roots of theDecalepis contain more of the amyrins and less of lupeol whereas theHemidesmus contains more of lupeol. The more soluble fractions of both roots seem to possess certain compounds having partly the properties of sterols and partly those of resinols. Further inHemidesmus roots small amounts of tetracyclic triterpene alcohols also seem to be present.

The latex ofCalotropis gigantea contains (1) resinols as esters of steamvolatile fatty acids (acetic and isovaleric), (2) cardiac poisons similar to usharin and (3) calcium oxalate. The resinol portion consists mainly of two new alcohols, α-calotropeol and β-calotropeol in almost equal quantities and minor amounts of β-amyrin. The important properties of the calotropeols have been studied. It is suggested that ‘Calosterol’ of Basu and Nath should be a mixture of resinols contaminated with cardiac poisons. The recent report of Hesseet al. that the milky latex ofCalotropis procera contains only α-lactucerol as its esters with steam-volatile fatty acids is discussed.

Past work on the chemical components of a number of plants of the family Asclepiadaceæ is reviewed. They are found to contain resinols though many of these were originally mistaken for sterols. With a view to test if this is an invariable rule another member,Leptadenia reticulata, has now been studied. The major portion of the wax consists of aliphatic wax esters derived from long-chain alcohols (C₂₈–C₃₄) and long-chain acids (C₂₈–C₂₂). Considerable amount of sterols occur free and the mixture seems to consist mostly of stigmasterol along with smaller amounts of sitosterols of which γ-sitosteral could be characterised. No resinols could be detected.

A study of the wax and resin components of the stem bark ofCalotropis gigantea is described. They were separated into fractions by means of alcohol. The most sparingly soluble fraction consisted of esters of resinols with long chain (saturated and unsaturated) fatty acids. From the unsaponifiable matter by fractionating the acetates and the benzoates, α-and β-calotropeols and β-amyrin were obtained. Small quantities of a mixture of possibly tetracyclic triterpene compounds and traces of sterols were also found to be present. A subsequent fraction was aliphatic being made up of 90% of fatty acids (C₃₀ and near homologues) and 10% of hydrocarbons (C₃₁+C₃₃, etc). The most soluble fraction contained esters of triterpene alcohols with steam volatile fatty acids. By a process of direct crystallisation applied repeatedly a new substance, Giganteol acetate, could be obtained from this fraction. It yielded a new dihydric alcohol, Giganteol, having the formula C₃₀H₅₀O₂.

An alcoholic extract of the wax-free stem bark yielded mineral matter consisting of citrates, chlorides and tartrates of sodium and potassium.

The wax and resin components of the root bark ofCalotropis gigantea have been examined. A substance corresponding to the description of ‘mudarol’ of previous workers could be isolated. However, its properties indicate that it is a triterpene alcohol and not a sterol. β-amyrin is also found as a major component. These two alcohols are present as esters of volatile and non-volatile fatty acids. β-amyrin acetate could be isolated by direct fractional crystallisation. No substance corresponding to the description of “akundarol” of Hill and Sirkar could be found.

Mudarol, the chief resinol component of the root bark ofCalotropis gigantea, has been separated into two isomeric compounds by fractional crystallisation of the acetates and also by chromatographic adsorption analysis of the free alcohols. Giganteol which was first obtained from the stem bark is one of them and a new triterpene alcohol, isogiganteol is the other. The properties and reactions of the new resinol are described. Though giganteol and isogiganteol (C₃₀H₅₀O₂) have two oxygen atoms they form only monoacetates. They do not combine with dinitrophenyl-hydrazine.

The waxy matter isolated from the flowers ofHibiscus sabdariffa by alcohol extraction yielded phytosterolin as the ether-insoluble component. The ether-soluble portion consisted mainly of hydrocarbons having chain lenghts round about C₂₇ along with very small amounts of sitosterol. By the extraction of safflower with carbon tetrachloride was obtained a wax made up mostly of paraffin of chain lenght C₂₉ and near homologues.

The ligroin extract of the flowers yielded waxy matter. One fraction of it consisted mainly of the esters of the resinols, α- and β-calotropeols and β-amyrin, with volatile as well as long chain fatty acids. There was also some sterol. The non-resinol aliphatic part contained mainly esters of wax acids and alcohols. The alcoholic extract of the wax-free flowers yielded only mineral matter—citrates, chlorides and tartrates of sodium and potassium.

The various parts ofCalotropis gigantea are compared with regard to the chemical components present in them.