L-Glutamine → Levopimaradienol

Participants

Reaction Steps

Ginkgo biloba “white nut” seeds were purchased from Dynasty Supermarket (Houston, Tex.). The seeds were stored at 4° C. for several days before sowing. Embryos were cultivated under aseptic conditions in an agar medium supplemented with D-glucose, L-glutamine, and Heller's salts at room temperature in the dark for four to six weeks (Schwarz, 1994). Synthesis of geranylgeraniol was performed as indicated in Ruan (1999) and Coates et al. (1978). Synthesis of geranylgeranyl diphosphate was performed as indicated by Corey et al. (1972), Davisson et al. (1985), and Davisson et al. (1986). Levopimarol was synthesized from levopimaric acid (Helix Biotech; New Westminster, British Columbia, Canada) according to procedures of Abad et al. (1985), Gigante et al. (1999), and Ayer and Talamas (1988). (6E,10E)-Geranyllinalool and pyridinium dichlorochromate were obtained from Fluka. All other reagents were obtained from either Sigma/Aldrich or Fisher Scientific, unless otherwise noted. Dichloromethane, dimethylformamide, methansulfonyl chloride, triethylamine, and toluene were freshly distilled over calcium hydride; tetrahydrofuran was freshly distilled over Na/benzophenone. Ammonium molybdate, ascorbic acid, tetrabutylammonium hydroxide, and citric acid were from ACROS. HP 20 polyaromatic dianion resin (250-850 μm) was purchased from Supelco.

Provenance & Evidence