Chemistry
Per 100 g, the seed is reported to contain 17.0–25.5 g protein, 3.0–3.3 g fat, 35.0–46.5 g NFE, 17.2–39.0 g fiber, 6.1–7.5 g ash, 1290–1500 mg Ca, 0.26–0.32 mg P. The predominant flavonoids in the heartwood are dihydrorobinetin (17.6%), robinetin (3,3',4',5',7-pentahydroxyflavone, 8%), 7,3',4',5'-tetrahydroxyflavan-3,4-diol (6.2%), and robtin (1.5%). Other flavonoids present in the heartwood are liquiritigenin, robtein, fustin, butin, butein, fisetin, 7,3',4'-trihydroxyflavan-3,4-diol, and 2',4',4-trihydroxy chalkone. Bark, leaves, and roots are reported to be toxic due to the presence of a toxal-bumin, robin (1.6% in the bark). Toxic symptoms are suggestive of those associated with belladonna poisoning. Bark also contains a glucoside robinitin (3%), syringin, tannin (up to ca 7.0%), some coloring matter and an unidentified, unstable alkaloid. Inner bark is reported to contain amygdalin, and urease. Leaves, considered antispasmodic and laxative, prescribed in digestive disorders, are poisonous to chicken. Leaves contain a coloring matter acacetin (apigenin-4'-methyl ether). Apigenin-7-bioside, apigenin-7-trioside, and indican, have also been reported. Leaves contain a volatile oil (0.01%) and carotene (209 mg/100 g). Hexene-3-ol (1) and trans-2-hexenal have been identified in the oil, the latter toxic to ciliates, such as Paramoecium. Flowers are powerfully diuretic due to the glycoside, robinin (kaempferol-7-1-rhamnosido-3'-robinobioside, 4.4%). Flowers also contain 1-asparagine a volatile oil and wax. The oil contains methyl anthranilate, linalool, a-terpineol, benzaldehyde, benzylalcohol, farnesol, heliotropin, indole, an aldehyde or ketone having a peach-like odor, and traces of pyridine-like bases. Seeds contain: moisture, 10.3–11.5; crude protein, 38.8–39.5; fat, 10.2–11.0; N-free extract, 20.4–23.0; crude fiber, 12.9–13.6; ash, 4.0–4.7; calcium (CaO), 0.19; and phosphorus (P2O5), 1.65%. Seeds contain the sugars sucrose, raffinose (traces) and stachyose, and the amino acids arginine and glutamic acid, and canavanine. Roots are rich in asparagine and are also reported to contain robin (C.S.I.R., 1946–1978).