| T. Kato et al., J. Antibiotics 29(12), 1339-1340, (1976). |
| S. Chihara et al., Agr. Biol. Chem. 37(11), 2455-2463, (1973). |
| Ibid. 37(12), 2709-2717, (1973). |
| Ibid. 38(3), 521-529, (1974). |
| Ibid. 38(10), 1767-1777, (1974). |
| T. Suzuki et al., J. Biochem. 56(4), 335-343, (1964). |
| J. M. Weber et al., J. Antibiotics 31(4), 373-374, (1978). |
| J. Shoji et al., J. Antibiotics 28, 764-769, (1975). |
| Ibid. 29(4), 380-389, (1976). |
| Ibid. (12), 1268-1274 (1976). |
| Ibid. (12). 1275-1280, (1976). |
| F. Benz et al., Helv. Chim. Acta 57, 2459, (1974). |
| C. Keller-JuSlen et al., Tetrahedron Letters, 4147-4150, 1976, vol. 46. |
| R. Traber et al., Helv. Chim. Acta 62, 1252, (1979). |