Potential biofuel exploitation from two common Vietnamese Euphorbia plants (Euphorbiaceae)

Abstract

In this work, two common Vietnamese Euphorbia plants, Euphorbia tirucalli Linn. (the milk bush) and Euphorbia tithymaloides Linn. (the milk hedge), have been investigated for potential use as biofuels. Their aerial parts were macerated with different solvents [petroleum ether, ethyl acetate (EA), methanol and water] to obtain extracts. The extracts were put through petrochemical composition analyses, including elemental analysis, Fourier transform infrared spectra recording and fatty acids composition analysis by HPLC. Subsequently, extracts were subjected to thermal gravimetric analysis for determination of some petrochemical contents. In addition, the gross calorific values (GCVs) of all extracts were determined and compared with those of other Euphorbia species and fuels. The obtained results showed the high petrochemical properties of Euphorbia tirucalli and moderately high ones of Euphorbia tithymaloides. Their estimated total rubber content values were then determined and compared with those of strains of other countries. The petroleum ether extract possessed the highest GCV, followed by the EA extract of E. tirucalli, then the EA extract of E. tithymaloides. Their GCVs were higher than those of some of other Euphorbia plants, conventional fuels like anthracite or lignite, and asymptotic to those of present fuels, including diesel and gasoline. Together with the plants’ well‐known tolerance of harsh conditions, such interesting phytochemical and petrochemical results significantly contribute to the potential for biofuel exploitation of Vietnamese E. tirucalli and E. tithymaloides.

Chromosome-level genome assembly of Euphorbia tirucalli (Euphorbiaceae), a highly stress-tolerant oil plant

“…Euphorbia, belonging to the family Euphorbiaceae, comprises about 2000 species and is one of the largest flowering plant genera in the world 1 . Many fuel plants have been reported in this genus, providing biomass for the production of biocrude, bioethanol and other bioenergy resources [2][3][4][5] . Euphorbia tirucalli (2n = 2x = 20) 6 , commonly referred to as milk bush, pencil cactus, pencil tree, or naked lady, is an evergreen shrub or small tree with typically succulent branched stems and small non-succulent leaves (Fig.…”

“…It exudes a milky latex from the wounded shoots or leaf stems 3,8 . Recent studies demonstrated that the compounds in the latex exhibit high petrochemical properties 5,9,10 . In addition, this species has important medicinal value, with its latex being traditionally used for the treatment of cancer, asthma, arthritis, rheumatism and so on [11][12][13][14] .…”

“…Due to the global energy crisis with the conventional fossil fuels and the associated environmental degradation 18 – 21 , E. tirucalli has received increasing attention in recent years, thanks to its fascinating petrochemical values and high tolerance to extreme habitats 4 , 5 , 22 , 23 . However, the utilization of such an important plant resource is severely hampered by the unavailability of genomic data.…”