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Leaves of N. schlechteri were collected from a tree (50 ft high, 3 ft in diameter) growing in rain forest along the Lae-Bulolo Road in the Oomsis Creek area (long. 146' 47' E., lat. 6' 43' S.). A voucher specimen TGH 10512 has been kept a t the Herbarium, Lae, Sew Guinea. Milled, dried leaves (6.8 kg) were extracted by continuous percolation with methanol, and the extract was concentrated a t 40' under reduced pressure. The concentrate was diluted with water and the pH adjusted to c. 2 by addition of dllute sulphuric acid. The acidified solution was extracted once with hexane, and then basified by addition of ammonia. Extraction with diethyl ether was then continued until a test portion of the extract no longer gave a positive test with Nayer's reagent. The ether solution was repeatedly extracted with dilute (IN) sulphuric acid until the acid extracts were negative to Mayer's reagent, and the acid extracts were basified with ammonia and extracted with chloroform. The chloroform extracts were dried and, on evaporation of the chloroform, 5.38 g crude alkaloids were obtained. The crude alkaloids a t this stage contained much non-alkaloidal material and the actual yield of alkaloids is estimated to be c. 0.02%. When a 1.0 g sample of the crude alkaloids was chromatographed on alumina (Spence H which had been neutralized by treatment with ethyl acetate), a series of fractions eluted by benzene and mixtures of benzene-chloroform consisted largely of waxy non-alkaloidal material. Elution with chloroform gave a series of fractions (c. 0.15 g) which crystallized readily on trituration with a small volume of chloroform or acetone. Crystallization from acetone gave the alkaloid as colourless needles, m.p. 162-165O, [ a ] ~ +45' (c, 0.10 in MeOH) (Found: C, 67.9; H, 7.5; N, 6.3. Calc. for

The identification of a leaf alkaloid of Neonauclea schlechteri (Rubiaceae) as gambirine (9-hydroxydihydrocorynantheine)