Two new steroidal alkaloids, 25-isosolafloridine (1a) and solacallinidine (1b), were obtained by hydrolysis of the crude glycoalkaloid extracted from Solanum callinum T. White ex R. J. Henderson (collected in south east Queensland in April 1972). 25-Isosolafloridine (1a) was isolated and purified via its hydrochloride salt; its structure was determined by X-ray diffraction on the hydrochloride salt, with spectroscopic data (IR, MS, 1H/13C NMR, CD) supporting characteristics such as the C=N chromophore, hydroxyl groups, and fragmentation typical of 22,26-imino-5α-cholest-22(N)-enes. Countercurrent distribution of the crude aglycone mixture yielded solacallinidine (1b), which was identified via spectroscopic analyses (IR, MS, 1H/13C NMR, CD) as 25-isosolafloridine with a 3β-amino group substituting the 3β-hydroxyl group—confirmed by 13C NMR comparison with 3β-amino-5α-cholestane. The CD spectra of both compounds showed negative Cotton effects at 242 nm, consistent with 25-S configuration. A synthetic 25-isosolafloridine reported earlier had different physical constants, possibly due to diastereoisomers. Solacallinidine (1b) is unusual for having two nitrogen atoms, being only the second dibasic Solanum alkaloid (after solanocapsine). All compounds gave satisfactory microanalyses.