The 1 H and 13 C NMR chemical shifts of 48 industrially preferred solvents in six commonly used deuterated NMR solvents (CDCl 3 , acetone-d 6 , DMSO-d 6 , acetonitrile-d 3 , methanol-d 4 , and D 2 O) are reported. This work supplements the compilation of NMR data published by Gottlieb, Kotlyar, and Nudelman (J. Org. Chem. 1997, 62, 7512) by providing spectral parameters for solvents that were not commonly utilized at the time of their original report. Data are specifically included for solvents, such as 2-Me-THF, n-heptane, and iso-propyl acetate, which are being used more frequently as the chemical industry aims to adopt greener, safer, and more sustainable solvents. These spectral tables simplify the identification of these solvents as impurities in NMR spectra following their use in synthesis and workup protocols.
New C-11 esters of the fermentation product wortmannin have been synthesized, with some of them further derivatized at C-17. The new esters show greater inhibition of isolated phosphatidylinositol 3-kinase and increased cell cytotoxicity in a rapidly proliferating leukemia cell line, when compared to wortmannin. Reduction of the C-17 ketone caused a slight increase in activity, while acylation of this new alcohol caused severe loss of activity. With their increased activity, the new C-11 esters may be good candidates to explore the in vivo antitumor effects of phosphatidylinositol 3-kinase inhibitors.
Forosamine at the 17-position of spinosyns A and D was hydrolyzed under mild acidic conditions to give the corresponding 17-pseudoaglycones. The tri-O-methylrhamnose at the 9-position of the 17-pseudoaglycone of spinosyn A was hydrolyzed under more vigorous acidic conditions to give the aglycone of spinosyn A. However, these conditions led to decomposition of the 17-pseudoaglycone of spinosyn D, presumably due to more facile protonation of the 5, 6-double bond to produce a tertiary carbonium ion which undergoes further rearrangements. Spinosyns J and L (3'-O-demethyl spinosyn A and D, respectively) obtained from fermentation of biosynthetically-blocked mutant strains of Saccharopolyspora spinosa, were oxidized to give the corresponding 3'-keto-derivatives and Spinosyns A (1) and D (2), formerly known as A83543A and A83543D, are two new commercially important macrolides and the most abundant of the 24 naturally occurring factors produced by the soil microorganism Saccharopolyspora spinosa.1,2) Together, in a mixture of approximately 85% 1 and 15% 2, they constitute the main active components of the new Dow Agrosciences insecticide Tracer3) and are potent insecticides against such crop pests as tobacco budworm.4) To initially establish the absolute configuration of 1 and to then provide new starting materials for further derivatization and semi-synthesis of new potentially useful insecticides, the two different sets of pseudoaglycones along with each of the aglycones were sought by selective degradation of the parent spinosyns. Our previous work had described the hydrolysis of the amino sugar forosamine from spinosyn A, giving the 17-
The spinosyns are a novel family of fermentation-derived natural products that exhibit potent insecticidal activities. Spinosad, a naturally-occurring mixture of spinosyn A and spinosyn D, has successfully established its utility for crop protective applications in the agrochemical field. Potential applications of this unique chemical family of macrolides also have been investigated in the field of animal health. Applications for the control of blowfly strike and lice on sheep have now been commercially developed and registered in Australia and potential applications for the control of ectoparasites on cattle are being studied.
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