@ Thomas Brendler
Ipomoea pes-caprae subsp. brasiliensis (L.) R. Br.
Common name: Patate a Durand (Reu.), railroad vine, goat’s foot vine, bayhops, beach morning glory
Synonyms: I. pes-caprae Brown, I. biloba Forsk., I. maritoma Roxb., Convulvulus bilobatus Roxb., C. brasiliensis Linne, C. maritimus Lamarck.
Family: Convulvulaceae
Botanical description: Perennial plant with trailing stem, 10–20 m long or more, rooting at the nodes. Leaves with a generally thick limb, with margin entire, ovate, obovate, subcircular or subquadrangular, reaching 8 cm in length and 7 cm in width, generally emaginate or bilobed at the summit. Inflorescence axillary, uni- or pauciflore and cymose; peduncle erect, 3–10 cm long; pedicels 1–3 cm long; sepals ovate-oblong, 5–10 mm long, the external ones a little smaller. Corolla pinkish mauve, with a darker centre, funnel-shaped, 3.5–5 cm long; limb spread out, 4 cm in diameter and with the lobes less marked. Capsule bilocular, subglobose, 12–18 mm in diameter, containing 4 seeds, around 7 mm long, dark brown, pubescent.
Country of origin: This species can be found on the sandy shores of the tropical Atlantic, Pacific and Indian Oceans. Common on the sand dunes of Australia’s upper north coast.
Key active ingredients: The plant contains resins, an essential oil, triaconthane, pentatriaconthane, sterols, and behenic, butyric, melissic and myristic acids. Further present are β-damascenone, triacontane, pentatriacontane. The seeds contain the alkaloids ergoline and clavine. The fatty acid glycosides present in the plant are pescaprosides A, B and E. Pescaproside E is the major compound and has been caracterised as being a pentaglycoside of 11-hydroxyhexa-decanol acid.
Brief history & traditional uses: The genus consists of some 500 species in tropical and warm temperate habitats. Ipomoea is used as a medicinal in many parts of the world. The leaves are used boiled for external application as an anodyne in colic or rheumatism. The leaf poultice is used to treat skin inflammations. In Mexico, the plant-based herbal medicine, is known under the registered name of ‘Rinonina’ and is sold in chemist shops.
Reported pharmacological activities: The plant shows antihistaminic and antiinflammatory properties in vitro. The effectiveness of the plant extract in the treatment of dermatitis is possibly due to the presence of b-damascenone and e-phytol, which interfere with contraction of vascular smooth muscle. Antinociceptive effects of a methanolic extract obtained from aerial parts have been described. This supports the popular use of I. pes-caprae to treat pain. A crude extract of I. pes-caprae also showed an inhibitory effect on prostaglandin synthesis in vitro. Bioassay-guided separation of the extract led to the isolation of 2-hydroxy-4,4,7-trimethyl-1(4H)-naphthalenone, (-)-mellein, eugenol, and 4-vinyl-guaiacol. The influence of these compounds on the formation of prostaglandins may partly explain a previously observed anti-inflammatory effect.