Isolation and structure of a new butyrolactone autoregulator from Streptomyces sp. FRI-5

Total synthesis and absolute configuration of avenolide, extracellular factor in Streptomyces avermitilis

“…The residue was purified by flash column chromatography (30:1 hexanes/EtOAc) to furnish the corresponding p-methoxybenzoate (8.38 g, 99%) as a colorless oil. 4 (71.5 mg, 0.19 mmol) and (DHQ) 2 PHAL (151 mg, 0.19 mmol) at 0 1C under N 2 . The reaction mixture was stirred for 4.5 h at 0 1C.…”

“…The combined organic extracts were Scheme 4 Reagents and conditions: the same reaction conditions as those described in Scheme 2 were used unless otherwise noted. (z) (À)-DET, Ti(Oi-Pr) 4 To a solution of the p-methoxybenzylidene acetal (697 mg, 3.14 mmol) in CH 2 Cl 2 (31 ml) was added DIBAL (1.02 M in hexanes, 9.00 ml, 9.41 mmol) at 0 1C under N 2 . After stirring for 1 h at 0 1C, the reaction was cautiously quenched with MeOH, diluted with CH 2 Cl 2 and treated with celite (2.80 g) and Na 2 SO 4 Á10H 2 O (2.80 g).…”

“…The reaction was quenched with H 2 O and the aqueous phase was extracted with CH 2 Cl 2 . The combined organic extracts were dried over anhydrous Na 2 SO 4 and concentrated in vacuo. The residue was purified by flash column chromatography (50:1 hexanes/EtOAc) to furnish 3 (188 mg, 89%) as a colorless oil.…”

“…The reaction was stirred for 30 min at À78 1C, then allowed to warm to 0 1C and stirred for 20 min. The reaction was quenched with a saturated aqueous NH 4 Cl and the aqueous phase was extracted with EtOAc. The combined organic extracts were dried over anhydrous Na 2 SO 4 and concentrated in vacuo.…”

“…[3][4][5] Other studies g-butyrolactones include IM-2 elicits production of showdomycin and minimycin in Streptomyces lavendulae FRI-5 [3][4][5] and SCB1 also elicits the precocious production of actinorhodin in Streptomyces coelicolor A3(2). [3][4][5] Genome-sequenced Streptomyces avermitilis is an important industrial microorganism for the production of anthelmintic and insecticidal macrocyclic lactone, avermectin, which is used as antiparasitic agents in the medical, veterinary and agricultural fields. To identify the extracellular factor(s) controlling avermectin production in Streptomyces avermitilis, about 1 mg of the extracellular factor from 1000 l of culture filtrate was isolated and purified by chromatographic separation steps.…”