489-84-9

DARK BLUE LOW MELTING CRYSTALLINE SOLID

AZ 8,Millet Roux

antioxidant, inhibits lipid peroxidation inhibitor, antiinflammatory, hepatoprotectant; LD50(rat) 1550 mg/kg po

ChEBI: Guaiazulene is a sesquiterpene. It derives from a hydride of a guaiane.

10 kg a gum of Guacum officinale was heated with 3-4 kg of sulfur to 130°C. The heating was slowly continued for 220°C under the nitrogen. The formed water steam was removed with the nitrogen current. The temperature should be higher 100°C in order to the water didnt fall into reaction mixture. H2S was obtained simultaneously the dehydrogenation and removed with water steam. Hydrogen sulfide was connected in an alkaline trap.
When a H2S discharge stopped, the temperature was decreased to 120°C and the reaction mixture was distilled in vacuum 1-20 mm. The distillate had deep blue color and contained 6-7 kg oil with 20% of 7-isopropyl-1,4- dimethylazulene. It was dissolved in the 5-10 volumes of light petroleum, shook with sodium hydroxide for removing the sulfur containing substaneces, washed to neutral. Then petrolem layer was mixed with 10-15 L 62% H2SO4 for removing the by-products, the petroleum layer lost the blue color and the desired substance was in sulphuric acid layer. The last one was shook with ice and NaOH. As a result about 7% NaSO4 solution in sulfuric acid was obtained. It was diluted and azulene gave an emulsion, which was extracted with 10 L of petrolem and distilled. The 7-isopropyl-1,4-dimethylazulene is distilled at 167°-168°C/12 mm. Yield 10-15%.

Antiinflammatory

It forms blue-violet plates from EtOH. Also redistil it in vacuo until distillate solidifies. UV has max at 284nm (log 4.6, heptane). The picrate has m 122o(EtOH). [Beilstein 5 III 1677, 5 IV 1751.]