4438 J. zyxwvutsrq Org. zyxwvutsrq Chem. zyxwvu 1990, 55, 4438-4443 (1 zyxwvutsrqponm H, ddd, J zyxwvutsrqpon = 14.5,6.4, and 4.7 Hz), 1.77 (1 H, ddd, J = 7.4,5.4, and 3.0 Hz), 1.82 (1 H, ddd, J = 7.4, 5.7, and 3.7 Hz), 1.91 (1 H, br t, J = 5.7 Hz), 2.17 (3 H, s COMe), 3.24 (3 H, zyxwvut s, OMe), 3.30 (3 H, s, OMe), 3.34 (3 H, s, OMe), 3.36 (3 H, s, OMe), 3.37 (1 H, m), 3.44 (2 H, m), 3.71 (1 H, t, J = 5.7 Hz), 5.08 (1 H, br d, J = 10.4 Hz), 5.10 (1 H, br d, J = 16.8 Hz), 5.81 (1 H, ddt, J= 16.8, 10.4, and 7.1 Hz); CIMS (isobutane) m/z 303 (MH+), 271 (MH+ - MeOH), 239 (MH+ - 2MeOH), 207 (MH+ - 3MeOH), 175 (MH+- 4MeOH). (3R,5R,7S,9S)-3,5,7,9-Tetramethoxy-lOsxoundecanal ( 15). To a stirred solution of 28 (17 mg, 0.056 mmol) in dioxane (1.2 mL) and water (0.4 mL) was added zyxwvutsrq 050, (1 mg). After stirring for 30 min at room temperature, NaI04 (50 mg, 0.27 mmol) was added and the reaction mixture was stirred for 1.5 h. The product was extracted from the mixture with ether and flash chromato- graphed (70% EtOAc-hexane) to give keto aldehyde 15 (12.4 mg, cm-'; 'H NMR (400 MHz, CDC13) 6 1.62 (1 H, dt, J = 14.3 and 5.5 Hz), 1.66 (1 H, dt, J = 14.3 and 5.5 Hz), 1.78-1.97 (4 H), 2.16 (3 H, s, COMe),2.63 (2 H, dd,J = 5.9 and 2.2 Hz),3.24 (3 H, s, OMe), 3.28 (3 H,s,OMe), 3.34 (3 H,s, OMe), 3.35 (3 H, s, OMe), 3.42 (2 H, m), 3.70 (1 H, t, J = 6.2 Hz), 3.84 (1 H, quintet, J = 6.2 Hz), 9.80 (1 H, t, J = 2.2 Hz); 13C (100 MHz, CDC1,) 6 25.44, 35.94, 37.26, 37.78,47.99,56.07,56.26,56.67, 57.91,73.51, 74.23, 74.69, 84.06, 201.21, 210.05; CIMS (isobutane) m/r 305 (MH'), 273 (MH+ - MeOH), 241 (MH+ - 2MeOH), 209 (MH+ - 3MeOH), 177 (MH+ - 4MeOH). Methyl (3R,5R ,7S,9S )-3,5,7,9-Tetramet hoxy- 10-oxo- undecanoate (16). To a solution of 28 (17.5 mg, 0.058 mmol) in dioxane (1.2 mL) and water (0.4 mL) were added KMnO, (2 73%): ["ID -21.49' (C 1.0); IR (CHCl3) 1720, 1460, 1355, 1010 mg) and NaI04 (62 mg), and the mixture was stirred for 2 h at room temperature. The reaction mixture was acidified with 1 % HCl and the carboxylic acid extracted out zyx with EtOAc. Treatment with ethereal diazomethane (2 mL) followed by flash chroma- tography (45% EtOAc-hexane) gave keto ester 16 (12.8 mg, 67%): ["ID -6.76O (c 0.7); IR (CHC13) 1720, 1435, 1100 cm-I; 'H NMR (400 MHz, benzene-d6) 6 1.64 (2 H, tt, J = 13.9 and 5.6 Hz), 1.84 (2 H, tt, J = 14.2 and 5.4 Hz), 1.93 (2 H, m), 1.94 (3 H, s, COMe), 2.41 (1 H, dd, J = 15.1 and 5.6 Hz), 2.54 (1 H, dd, J = 15.1 and 6.6 Hz), 3.05 (3 H, s, OMe), 3.11 (3 H, s, OMe), 3.12 (3 H, s, OMe), 3.16 (3 H, s, OMe), 3.35 (3 H, s, OMe), 3.46 (1 H, quintet, J = 5.6 Hz), 3.54 (1 H, quintet, J = 5.9 Hz), 3.60 (1 H, triplet, J = 5.9 Hz), 3.84 (1 H, quintet, J = 5.9 Hz); 13C (100 MHz, CDC13) 6 25.48, 36.05, 37.44, 37.88,39.25, 51.64, 56.16,56.29, 56.86, 57.93, 74.32, 74.86, 74.96, 84.16, 171.98, 210.08; CIMS (isobutane) m/z 335 (MH+), 303 (MH+ - MeOH), 271 (MH+ - 2MeOH), 239 (MH+ - 3MeOH), 207 (MH+ - 4MeOH). Acknowledgment. This research was supported by Grant No. CA12623 from the National Cancer Institute, Department of Health and Human Services. A GN500- Omega NMR spectrometer at the University of Hawaii that was used in this study was purchased with a grant from the National Science Foundation. We thank Faith Caplan and Linda K. Larsen for determining the cyto- toxicities and antifungal activities and Drs. Thomas Cor- bett and Frederick Valeriote (Division of Hematology and Oncology, Wayne State University School of Medicine) for evaluating the compounds for selective cytotoxicity. Synthesis of Deuterium- and 15N-Containing Pyrroline 1-Oxides: A Spin Trapping Study Sovitj Pou and Gerald M. Rosen* Department of Pharmacology & Toxicology, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, and Veterans Administration Medical Center, Baltimore, Maryland 21218 Yexin Wu and John F. W. Keana* Department of Chemistry, University of Oregon, Eugene, Oregon 97403 Received March 19, 1990 Our aim is to develop nitrone-based spin traps with improved sensitivity toward superoxide and hydroxyl radicals through isotopic substitution. Deuterated DMPO derivatives were prepared by either D20-NaOD or D,O-DCl exchange reactions. The 16N-substituted counterparts were synthesized starting with acetone-de and (15N)- hydroxylamine. These spin traps provide significantly enhanced sensitivity in the detection of superoxide and small carbon-centered free radicals. In recent years reduced oxygen species, including su- peroxide and hydroxyl radical, have been studied inten- sively as these reactive intermediates appear to play an important role in mediating a variety of pathologic con- ditions. For example, it has been proposed that during ischemia/reperfusion injury, free radicals initiate events leading to cellular necrosis.'S2 Yet, data in support of this hypothesis is largely indirect, coming from the observation that in vivo, free radical scavengers significantly ameliorate the injury. Of the available methods for the detection of free rad- icals, only spin trapping offers the opportunity to simul- taneously measure and distinguish among a variety of (1) Granger, D. N.; Rutili, G.; McCord, J. M. Gastroenterology 1981, (2) Bulkley, G. B. Brit. J. Cancer 1987, 55, Supp. VIII, 66. 81, 22. 0022-3263/90/1955-4438$02.50/0 important biologically generated free radical^.^-^ In this technique, a nitrone or nitroso compound reacts with a short-lived free radical to produce a nitroxide whose life- time is considerably greater than that of the parent free radical.e The spin trap 5,5-dimethyl-l-pyrroline 1-oxide (DMPO, 8) is most frequently used; however, this nitrone has several limitations. Its reaction with superoxide is rather slow, having a second-order rate constant of only 10 M-* 5-l.' Its partition coefficient was found to be only (3) Finkelstein, E.; Rosen, G. M.; Rauckman, E. J. Arch. Eiochem. Biophys. 1980, 200, 1. Academic Press: New York, 1980; Vol. 4, p 116. 345. (4) Janzen, E. G. In Free Radicals in Biology; Pryor, W. A,, Ed.; (5) Rosen, G. M.; Finkelstein, E. Adu. Free Rad. Biol. Med. 1985, 1, (6) Janzen, E. G. Acc. Chem. Res. 1971, 4, 31. (7) Finkelstein, E.; Rosen, G. M.; Rauckman, E. J. J. Am. Chem. SOC. 1980, 102,4994. 1990 American Chemical Society