Swamp mahogany

Family • Myrtaceae - Eucalyptus robusta Sm. - BEAKPOD EUCALYPTUS - Lan an

Scientific names

Eucalyptus robusta Sm.
Eucalyptus robusta var. bivalva Blakely
Eucalyptus robusta Sm. var. robusta
Eucalyptus multiflora Poir.

Other vernacular names

SWAHILI: Mkaratusi.

Common names

Australian brown mahogany (Engl.)
Beaked eucalyptus (Engl.)
Beakpod eucalyptus (Engl.)
Brown gum (Eng.)
Red gum (Eng.)
Swamp mahogany (Engl.)
Swamp messmate (Engl.)
Swamp stringybark (Engl.)

Eucalyptus robusta is a tree growing to a height of 20 to 30 meters, with a straight trunk up to 1 meter in diameter. Bark is coarse, stringy, dark-brown, and grooved. Branches are long, spreading, irregular, providing a dense canopy. Leaves are alternate, leathery, broadly lanceolate, 10 to 18 centimeters long, about 8 centimeters wide, and long pointed. Flowers are white or creamy white, in compound clusters of 7 to 13 flowers. Fruit is 1.5 centimeters long, becoming woody when dry.

Swamp Mahogany

Additional Sources and Suggested Readings

(1) Eucalyptus robusta / Wikipedia

(2) Studies on the chemical constituents of Eucalyptus robusta Sm.: Isolation and identification of robustaol B and other constituents / Qin Guo-Wei, Xu Ren-Sheng / Acta Chimica Sinica, Volume 4, Issue 1, pages 62–67, March 1986 / DOI: 10.1002/cjoc.19860040110

(3) Repellent Activity of Eight Essential Oils of Chinese Medicinal Herbs to Blattella germanica L. / Zhi Long Liu*, Meng Yu, Xiao Mei Li, Tao Wan and Sha Sha Chu / Rec. Nat. Prod. 5:3 (2011) 176-183

(4) Chemical constituents of the essential oil from the leaves of Eucalyptus robusta and its antimicrobial activity / Journal of Fujian College of Forestry, 2007-01Add to Favorite Get Latest Update/ DOI: CNKI:ISSN:1001-389X.0.2007-01-010

(5) Eucalyptus robusta Sm / Protabase

(6) Evaluation of insecticidal activity of the essential oil of Eucalyptus robusta Smith leaves and its constituent compound against overwintering Cacopsylla chinensis (Yang et Li) (Hemiptera: Psyllidae) / Xin Chao Liu, Qi Zhi Liu, Wang Peng Shi, and Zhi Long Liu / Journal of Entomology and Zoology Studies 2014; 2 (4): 27-31

(7) Analysis of flavonids of Eucalyptus robusta. sm and study of antibacterial activation / Wang Yuefeng, Yu Yanchun, Yang Guojun, Wei Bogui, Ma Chaoying / Chinese Archives of Traditional Chinese Medicine [2004, 22(11):2135,2143]

(8) Euglobal-IIIa, a novel acylphloroglucinol-sesquiterpene derivative from Eucalyptus robusta: absolute structure and cytotoxicity / Li-Yan Peng, Juan He, Gang Xu, Xing-De Wu, Liao-Bin Dong, Xiu Gao, Xiao Cheng, Jia Su, Yan Li, Qin-Shi Zhao / Natural Products and Bioprospecting, October 2011, Volume 1, Issue 2, pp 101-103

(9) A phenylalanine ammonia-lyase gene (ErPAL1) from Eucalyptus robusta: molecular cloning, expression and characterization (Molecular cloning of ErPAL1 from cultured eucalyptus cells) / Shinya AKIMOTO*, Takahisa ISHINO*, Tamami TERADA*, Masahiro SAMEJIMA*, Shigehiro KAMODA** / Bull. Univ. of Tokyo For, 128, 121- 137 (2013)

Swamp Mahogany2

– Native to Australia.
– Planted as a timber tree.
– Exotic in Argentina, Brazil, Cameroon, Chile, China, Colombia, Comoros, Congo, Costa Rica, Democratic Republic of Congo, Ethiopia, Fiji, Honduras, Hong Kong, India, Kenya, Madagascar, Malawi, Malaysia, Mauritius, Mexico, Mozambique, Papua New Guinea, Paraguay, Philippines, Puerto Rico, South Africa, Sri Lanka, Taiwan, Province of China, Tanzania, Uganda, United States of America, Zanzibar
– In the Philippines, cultivated as an ornamental tree in Baguio City and other highland areas.

Swamp Mahogany3

• Gum contains about 30% tannin.
• Essential oil yield is 1.7%, with principal constituents of piperitone, rhocymene, linalool, 1,8,-cineole, terpinen-4-ol, citronellyl acetate and alpha-terpinol.
• Study of essential oil for repellency yielded: α-pinene (28.74%) and 1,8-cineole (27.18%), spathulenol (6.63%), globulol (6.53%) and ρ-menth-1-en-8-ol (5.20%).
• Study of leaves yielded a newnine known compounds, 5-hydroxy-4′,7-dimethoxy-6,8-dimethylflavone, 4′,5-dihydroxy-7-methoxy-6,8-dimethylflavone, 3β-hydroxy-urs-11-ene-28-oic-13(28)-lactone, 3β-acetoxy-urs-11-ene-28-oic-13(28)-lactone, uvaol, β-sitosterol, 7β-O-glucoside of 5,7-dihydroxy-2-methylchromone, 1-triacontanol and 1-triacontanoic acid, and a new acylphloroglucinol named robustaol B 6, shown to be 4,6-dihydroxy-2-methoxy isobutyrophenone.
• Study of ethanol extract of leaves yielded three active compounds, Robustaol A, Robustadial A and Robustadial B.

Swamp Mahogany4Properties
• Leaves are aromatic when crushed.
• Antimalarial, antimicrobial, repellent.

Parts used
Leaves, oil.

– No recorded folkloric medicinal use in the Philippines.
– In China, leaves are used for the treatment of malaria, dysentery, and bacterial diseases.
– In Gabon, infusion of leaves used for malaria.
– In Mauritius and Reunion, leaves used for baths, inhalations and infusions to treat fever, colds, cough and influenza.
– Inhalations used for asthma, sinusitis.
– Infusions used for diabetes.
– Decoction used for baths in rheumatism, epilepsy and stiffness.
– In Madagascar, buds are squeezed and the sap applied to the nostril to relieve headache.

– Apiculture: Flowers provide significant forage for bees and honey production.
– Fuel: Used for firewood and charcoal.
– Timber: Heartwood is extremely durable and resistant to marine borers. Used for fencing and construction of wharves.
– Pulp: Can be used as complementary raw material for commercial scale pulp production.

Study Findings
• Antibacterial / Constituents: Study of leaves yielded a new acylphloroglucinol named robustaol B 6, plus 9 known compounds. Robustaol B6 showed inhibition against Staphylococcus aureus and Bacilus subtilis.
• Cockroach Repellent Activity / Constituents: Study evaluated the repellent activity of 8 essential oils of Chinese medicinal herbs (Angelica sinensis, Curcuma aeruginosa, Cyperus rotundus, Eucalyptus robusta, Illicium verum, Lindera aggregate, Ocimum basilicum and Zanthozylum bungeanum. On a scale of Class I (weak repellency) to Class V (strong repellency), E. robusta showed Class IV repellency, using its essential oil plus the two compounds α-pinene and 1, 8-cineole, against nymphs of the German cockroach Blatella germanica.
• Antimicrobial / Leaf Essential Oil: Study of leaves essential oil showed antimicrobial effect against E coli and Staphylococcus aureus. Monoterpene and oxygen-containing monoterpenes were the major constituents.
• Insecticidal Against Cacopsylla chinensis / Essential Oil: Chinese pear psylla, Cacopsylla chinensis is one of the main pests of pear trees in China. The two main constituent compounds, α-pinene and 1,8-cineole, exhibited strong acute toxicity against overwintering Chinese pear psylla.
• Flavonoids / Antibacterial: Crude extraction by polyamide yielded flavonoids (0.903%). The antibacterial activation to E. coli, S. aureus and B. cactus is much better than oxytetracycline.
• Euglobal-IIIa / Cytotoxicity to Five Human Cancer Cell Lines: Leaves of Eucalyptus robusta yielded a novel acylphloroglucinol-sesquiterpene derivative, euglobal-IIIa, and a known analogue. Euglobal-IIIa exhibited cytotoxicity comparable with that of cisplatin against five human cancer cell lines.
• ErPAL1 / Phenylalanine Ammonia-lyase (PAL): PAL is the first enzyme of the phenylpropanoid pathway that produces precursors of compounds which play essential roles during plant development and defense.