Two new alkaloids isolated from the leaves of Elaeocarpus dolichostylis Schl. bear a close relationship to the alkaloids (±)-elaeocarpine (I) and (±)-isoelaeocarpine (II) previously obtained from Elaeocarpus polydactylus Schl. The isomeric alkaloids (+)-elaeocarpiline and (-)-isoelaeocarpiline, with molecular formula C₁₆H₂₁NO₂, are shown to be (+)-15,16-dihydroelaeocarpine (III) and (-)-15,16-dihydroisoelaeocarpine (IV), in which the relative stereochemistry at C-16 and the absolute configuration remain unassigned. (+)-Elaeocarpiline (III), m.p. 165-166℃, [α] +395° (CHCl₃), has M⁺ at m/e 259, λmax (EtOH) 221, 241 infl, 323 mp (ε 5000, 4600, 7200), and νmax (CCl₄) 1657 cm⁻¹ typical of a conjugated dienone system. Its n.m.r. spectrum has signals at δ 0.95 (3H, d, J 6-7 c./sec., methyl at C-16), 6.27 (m, 14-H), 5.85 (q, 13-H, Jvic 10.0 c./sec., Jail 2-9 c./sec.), and a broad multiplet at δ 4.06 (7-H) similar to that in (+)-elaeocarpine (I), consistent with trans-diaxial C-7 and C-8 protons. Heating (III) with 10% palladium-charcoal in benzene affords (+)-elaeocarpine (I), identical in i.r., n.m.r., and mass spectra to (±)-elaeocarpine. (-)-Isoelaeocarpiline (IV), m.p. 146-147℃, [α] -400° (CHCl₃), M⁺ 259, λmax (EtOH) 224, 240 infl, 323 mp (ε 3700, 3500, 7700), νmax (CCl₄) 1657 cm⁻¹, is isolated from E. dolichostylis in larger amounts than (III). Its n.m.r. spectrum shows δ 0.85 (d, 16-Me, J 6.7 c./sec.), 6.26 (m, 14-H), 5.88 (q, 13-H, Jvic 10.0, Jail 2-8 c./sec.), and a narrow multiplet at δ 4.54 (7-H) resembling that in (±)-isoelaeocarpine (II), indicating a cis-7,8 ring junction. Heating (IV) with palladium-charcoal in benzene gives (-)-isoelaeocarpine (identical to (±)-isoelaeocarpine in spectra) and (-)-13,14,15,16-tetrahydroisoelaeocarpine (m.p. 121-122℃, [α]D -219° (CHCl₃), M⁺ 261, λmax (EtOH) 275 mp (ε 8900), νmax (CCl₄) 1667 cm⁻¹). With sodium borohydride in ethanol at room temperature, the 13,14-double bond of (-)-isoelaeocarpiline (IV) is reduced to (-)-13,14,15,16-tetrahydroisoelaeocarpine without affecting the carbonyl group; (+)-elaeocarpiline (III) reacts similarly to give a tetrahydro-derivative (alcohol V, m.p. 197-198℃, [α] +135° (CHCl₃), M⁺ 263). Hydrogenation of (III) over platinum oxide in ethyl acetate gives (+)-13,14,15,16-tetrahydroelaeocarpine (m.p. 92-94℃, [α] +317° (CHCl₃), λmax (EtOH) 273 mp (ε 8900), νmax (CCl₄) 1666 cm⁻¹). A new phenolic alkaloid, isoelaeocarpicine, C₁₆H₂₁NO₃, m.p. 164-166℃, [α] +29° (CHCl₃), M⁺ 275, νmax (CHCl₃) 1665 cm⁻¹, λmax (EtOH) 248 and 294 mp (ε 3150, 2100), is isolated from E. Polydactylus leaves with (I) and (II), differing by H₂O in molecular composition. It is shown to be (VI) as warming with potassium hydroxide in methanol converts it to (I) of low optical rotation ([α] +20° in CHCl₃) and essentially racemic (II). Its n.m.r. spectrum has signals at δ 4.30 (7-H, couplings similar to those in isoelaeocarpine) and δ 3.82 (q, J₇,₈ 2.5, J₈,₉ 11.0 c./sec., 8-H), indicating cis axial-equatorial C-7 and C-8 protons and equatorial conformation of the bulky substituent at C-8 of the indolizidine ring. E. dolichostylis, occurring in New Guinea like previously examined species, has leaves containing (III), (IV), indole alkaloid elaeocarpidine, and traces of (I) and (II).