198
- Streptovaricin .. . . . ..
(11) R. S. Cahn,C. K. ingold, andV. Prelog, Angew. Chem., 78, 413(1966). (12) The relative configurations at C-8 through C-14 of atropisostreptovaricin c vis-a-vis C-6 and C-7 and the ansa bridge were inadvertently represented incorrectly in the twodimensional drawing of the earlier reportg The threedimensional figure theres and the twodimensional representation for 12 shown in Figure 1 are correct. (13)J. Leitich. W. Oppolzer, and V. Prelog, Experientia, 20, 343 (1964). (14) M. Brufani, W. Fedeli. G. Giacomello, and A. Vaciago, Experientia, 20, 339 (1964). (15) K. Kamiya, T. Sugino, Y. Wada, M. Nishikawa, and T. Kishi. Experientia, 25, 901 (1969).
C
Alropisostreptovaricin C
___-
--
-32
-V
200
j
280
360
Streptovoricin C triacetate p-brornobenzenaboronate Atropisostreptovoricin C triacetate P-brornobenzaneboronate
I
I
440
520
I
Kenneth L. Rinehart, Jr.," Waltraut M. J. Knoll Katsumi Kakinuma Frederick J. Antosz, Iain C. Paul Andrew H.-J. Wang School of Chemical Sciences, University of Illinois Urbana, Illinois 61801
1
600
nm
Figure 2. Circular dichroism curves for streptovaricin C (1). its atropisomer (2), streptovaricin C triacetate p - bromobenzeneboronate (1l ) , and its atropisomer (12).
tion was carried out on the negative-rotating ("late," unnatural) isomer and the actual relative configuration of the natural streptovaricins must be that shown in Figure 1 (1, 4, 7, 9, 11). To assign the absolute configuration of 12, the two possible enantiomorphs (i.e., 12 and its mirror image) were refined including the anomalous scattering contributions for the bromine and chlorine atoms. The enantiomorph 12 converged with a value of R2 of 0.101, whereas the opposite enantiomorph converged with R2 of 0.104, arguing that the absolute configuration is as shown for 12; thus, that for the natural streptovaricin is that shown, e.g., for 1 (6R. 7R, 8R, 9R, l O S , 11s' 12R, 13S, 14R, helicity P)," which agreesi2 with the helicity and absolute configurations a t C8 through C-14 of rifamycin BI33I4and tolypomycin Y . i s To our knowledge these represent the first examples of the conversion of a naturally occurring compound to its atropisomer . Acknowledgment. This work was supported by Public Health Service Research Grants AI 1278 from the National Institute of Allergy and Infectious Diseases and G M 19336 from the National Institute of General Medical Sciences and by Contract NIH-NCI-C-72-3208 from the Division of Cancer Treatment, National Cancer Institute. High resolution and field desorption mass spectra were obtained on a mass spectrometer provided by grants from the National Cancer Institute ( C A 11,388) and National Institute of General Medical Sciences ( G M 16864).
Fritz Reusser, L. H. Li, William C. Krueger The Upjohn Company Kalamazoo, Michigan 49001 Received September 24, 1974
On the Mechanism of Firefly Luciferin Luminescence' Sir:
The bioluminescence and the chemiluminescence of firefly luciferin (Ia)2 are closely related processes in that both require ~ x y g e n , both ~ . ~ produce carbon dioxide5.6 and lactam IIIa,337 and both yield yellow-green or red light depending on the c ~ n d i t i o n s . ~On J the basis of these facts, the identification of lactam 111 as the light e m i t t e ~ - ,and ~ . ~ analogy to other chemiluminescent reactions, the mechanism of eq 1 was proposed for both the chemi- and bioluminescence of firefly l ~ c i f e r i n ~ .(where ~ - ~ ~ X = any good leaving group). Since that time, 1,2-dioxetanes have been isolated,I2 and their chemistry has been elucidated;I3 they are, in fact, excellent sources of chemically produced excited states.14 n
R
R
1
IaR=H;X=OH b,R=H:X=AMP
References and Notes Presented in part at the 165th National Meeting of the American Chemical Society, Dallas, Texas, April 1973, Abstracts, MEDl 002. Paper XI1 in the Series "Chemistry and Biochemistry of the Streptovaricins." Paper XI: K. L. Rinehart, Jr., F. J. Antosz, K. Sasaki. P. K. Martin, M. L. Maheshwari, F. Reusser, L. H. Li. D. Moran, and P. F. Wiley, Biochemistry, 13, 861 (1974). Reviews: (a) K. L. Rinehart, Jr., Accounts Chem. Res., 5, 57 (1972): (b) W. Wehrli and M. Staeheiin, Bacteria/. Rev.. 35, 290 (1971). For a discussion of atropisomerism, see E. L. Eliel. "Stereochemistry of Carbon Compounds," McGraw-Hill, New York. N.Y., 1962, pp 156-178. Molecular formulas established by (a) microanalyses, (b) low resolution mass spectrometry, and (c) high resolution mass spectrometry. These arguments assume that the helicity of the molecules accounts for their very high rotations, an assumption in keeping with the much lower rotation of streptoval C (3,vide infra). Streptovais C (3) and FC (6) have no stable hellcity since their atropisomeric forms, like those of streptovarone,8binterconvert at room temperature, a conversion demonstrated by the broadening of the methylenedioxy signals in the pmr spectra of streptovarone,8b3 and 6. (a) K. Kakinuma, B. I. Miiavetz, and K. L. Rinehart, Jr., to be submitted; (b) K. L. Rinehart, Jr., C. E. Coverdale, and P. K. Martin, J. Amer. Chem. SOC., 88, 3150 (1966). A. H . J . Wang, I. C. Paul, K. L. Rinehart. Jr., and F. J. Antosz, J. Amer. Chem. Soc.,93, 6275 (1971). K. L. Rinehart, Jr., J. C. Cook, Jr., K. H. Maurer, and U. Rapp, J. Antibiot., 27, l(1974).
Journal of the American Chemical Society
R IIIaR=H c. R = CH
Oxygen-I8 studies of both the bio- and chemiluminescence of firefly luciferin (via the adenylate Ib) have been reported recently purporting to show that the carbon dioxide formed in the reactions was not labeled in bioluminescence (enzyme IsO2in H 2 0 ) and labeled to less than 10% in chemiluminescence (tert- butoxide iSO2in DMSO).I5 In both reactions, it was further claimed that one oxygen atom of the carbon dioxide was derived from water.I5 The mechanism of eq 2 was proposed to account for these results.'5 In a related study, bioluminescence in the sea pansy led to
