As a result of decreasing supplies of f ossil hydrocarbons it has become recessary to reexamine other sources of raw materials f or possible conversion into hydro-carbons. In connection with the utilization of solar energy for renewable resources, the auther has been concerned with the lipid analysis of photosynthesizing plants such as rubber tree (Hevea brasiliensis), some dif ferent species of Euphorbia and other latex-bearing plants which grow naturally in tropical and temperate regions. The results have indicated that Euphorbia plants, e. g. E. tirucalli and E. lathyris contain a large amount of lipids such as triglycerides and steroidal triterpenes (about 1 to 2%w/w of the fresh plant). However, since Euphorbia plants have co-carcinogenic and toxic substances, e. g. diterpene esters, the industrial production of these oil might give rise to environmental problems such as air pollution.
It is well known that Eucalyptus plants (some 600 species) also produce amount terpeoidal hydrocarbons. The most fascinating Eucalyptus plants which contain a large of oils have been explored. As the result, E. radiata, which is one of good canditotal. dates was discovered in Australia. It consists of 4.2% volatile and 4.5% non-volatile in total. Namely, about 95l or 8.7% (w/w) of ether-acetone soluble oil is gotten from one ton of the fresh juvenile E. radiata. The utilization of residue which contains cellulose and lignins is also very important. The microbiological biomass conversion of the Eucalyptus residue should be studied.
