Baeckea frutescens (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Baeckea frutescens L.

Protologue: Sp. pl. 1: 358 (1753).

Family: Myrtaceae

Chromosome number: 2n= unknown

Synonyms

• Baeckea chinensis Gaertner (1788),
• Baeckea cumingiana Schauer (1843),
• Baeckia cochinchinensis Blume (1849).

Vernacular names

• Indonesia: junjung atap (Bangka), jung rabab (Javanese), jhung rahab (Madurese)
• Malaysia: chuchur atap, cucuran atap, hujong atap
• Cambodia: moreck ansai
• Thailand: son naa, son saai (peninsular), son hom (south-eastern)
• Vietnam: chổi xuể, chổi sẻ, thanh hao.

Origin and geographic distribution

B. frutescens is widespread from South-East Asia to Australia, including southern China, Thailand, Peninsular Malaysia, Sumatra, Borneo, Sulawesi and New Guinea. It is not known to occur in Java, the Lesser Sunda Islands or the Philippines.

Uses

Throughout South-East Asia, the flowers and leaves of B. frutescens are made into a herbal tea. In Malaysia and Indonesia, it is traditionally associated with health drinks and powders used during childbirth. In Indonesia (Sumatra, Java) the leaves are used as an emmenagogue. In Vietnam all aerial parts are credited with antibacterial, antifebrile and haemostatic properties. It is indicated in the therapy of coryza, influenza, headache, measles, colic and jaundice, in the form of a fumigation of the dried plant or the inhalation of vapour from a boiling decoction of the fresh plant. It is also prescribed against epistaxis, impetigo, dyspepsia, dysentery and menstrual disorders. It is externally applied as an antiseptic in treating furunculosis and impetigo. The essential oil is used for massage in cases of rheumatism. In Indo-China leaves are occasionally put among clothing to keep insects away. In Hong Kong aerial parts are used to treat snakebite. The branches are used as brooms. The timber is hard, dark brown and very durable but of small dimensions.

Production and international trade

Dried parts of B. frutescens have been part of inter-island trade in Malaysia and Indonesia for centuries. The present day situation is unclear, but volumes are believed to be as high as 10-20 t per year.

Properties

The aerial parts of B. frutescens contain an essential oil. The essential oil obtained by steam distillation of leaf material of B. frutescens obtained in 4 different sites in Malaysia showed considerable variation in composition and relevant percentage of its constituents. Three of the samples were dominated by pinenes (40-55.5%), the other sample was dominated byγ-terpinene (34%). 1,8-Cineole was prominent in three samples but absent in the fourth. Other compounds that were found as major components in most of the samples were p-cymene, limonene, linalool,α-terpineol,β-caryophyllen andα-humulene. Three sesquiterpenes have been isolated from the dichloromethane extract of the herb, 2 of them being also well known constituents of several essential oils; humulene epoxide, caryophyllene epoxide, and a new constituent clovane-2,9-diol. In a simple in vitro enzyme assay, the essential oil of B. frutescens showed strong inhibitory activity of more than 80% at 0.1 mg/ml against lipoxygenase. The essential oil at a dose of 435 mg/kg exhibited antihepatotoxic activity against artificially induced liver injury in mice.

Furthermore, from the leaves and aboveground parts, series of chromones, chromanones, as well as chromone-C-glycosides have been isolated. Chromones are structurally strongly related to the flavones: they lack the aromatic B-ring of the flavones, and in an analogue way, the chromanones are related to the flavanones. 5-Hydroxy-7-methoxy-2-isopropylchromone and 5-hydroxy-7-methoxy-2-isopropyl-8-methylchromone are examples of isolated chromones, 2,5-dihydroxy-7-methoxy-2-isopropylchromanone is the related chromanone.

In addition to the chromone derivatives, 3 flavanones (BF-4, BF-5, BF-6), and 2 phloroglucinols (BF-1 and BF-2) have also been isolated from the leaves. Compounds BF-2, BF-4 and BF-5 showed strong cytotoxic activity against leukaemia cells (L 1210) in tissue culture with an IC₅₀ of 5, 0.25 and 0.25μg/ml, respectively.

Adulterations and substitutes

In trade the leaves of B. frutescens are sometimes used as a substitute for those of Leptospermum (Myrtaceae).

Description

• An evergreen, heather-like shrub or small tree up to 8 m tall; bark greyish brown, fissured and flaky; branches upright, then spreading and drooping, with wiry ends.
• Leaves opposite, seemingly in clusters at condensed nodes, needle-like, 6-15 mm × 0.4-0.8 mm, base narrowly cuneate, apex obtuse or acute, margin entire, resinous aromatic when crushed; petiole 0.5 mm long.
• Inflorescence axillary, 1-flowered; peduncle absent or very short; pedicel 0.8-1.7 mm long; bracteoles 2, early caducous.
• Flowers bisexual, 5-merous, hypanthium obconical to campanulate, 1.5-2.2 mm long, partly fused to the ovary; sepals semiorbicular, 0.4-0.9 mm × 0.6-1.1 mm; corolla up to 5 mm across, petals orbicular, 1.1-1.8 mm across, white, oil glands present; stamens 7-13 in groups of 1-3 opposite each hypanthium lobe, filament 0.5-0.8 mm long, anther about 0.3 mm long; ovary 2-3-locular, 12-18 ovules per locule, style terete, about 1.2 mm long.
• Fruit a hemispherical to campanulate capsule opening by 3-4 longitudinal slits.
• Seedling with epigeal germination; cotyledons small, green; hypocotyl elongated; leaves opposite, needle-like.

Growth and development

Growing near the sea or in sheltered locations on mountains, B. frutescens becomes a small tree with switchy twigs, resembling Casuarina spp. On exposed peaty soils and rocky mountain tops, it grows as a dwarf shrub like a heather, with a gnarled woody stem and branches flattened against the soil surface.

Other botanical information

The large genus Baeckea has recently been split up into five genera including Babingtonia, Ochrosperma, Rinzia and Triplarina; the latter three are endemic to Australia. Baeckia in the narrow sense comprises 14 species, 13 of which are confined to Australia. With the exception of B. frutescens, Baeckia species are of temperate climates.

Ecology

B. frutescens grows on poor sandy and ultrabasic soils, in shrubland, often at high altitudes. It is also present in seasonally wet savanna and swamp forest.

Propagation and planting

Seeds of B. frutescens germinate in 52-66 days.

Harvesting

In Vietnam, the whole plant of B. frutescens except the roots is harvested during its flowering period in July-October.

Handling after harvest

The aboveground parts of B. frutescens are dried in the sun or artificially. The essential oil can be obtained by distillation.

Genetic resources and breeding

B. frutescens is widespread and common throughout South-East Asia, and therefore not endangered.

Prospects

Some information on the phytochemistry of B. frutescens is available which e.g. reveals the presence of chromone-derivatives, flavanones and phloroglucinols. The in vitro cytotoxic activity of the flavones might be of interest, and therefore these, and possible related compounds, merit further research.

Literature

• Bean, A.R., 1997. A revision of Baeckea (Myrtaceae) in eastern Australia, Malesia and south-east Asia. Telopea 7(3): 245-268.
• Fujimoto, Y., Usui, S., Makino, M. & Sumatra, M., 1996. Phloroglucinols from Baeckea frutescens. Phytochemistry 41(3): 923-925.
• Jantan, I., Ahmad, A.S., Bakar, S.A.A., Ahmad, A.R., Trockenbrodt, M. & Chak, C.V., 1998. Constituents of the essential oil of Baeckea frutescens L. from Malaysia. Flavour and Fragrance Journal 13(4): 245-247.
• Ling, S.K., Shaari, K., Ali, R.M. & Ali, N.A.M., 1998. Lipoxygenase inhibitory activity of selected plant extracts and essential oils. Journal of Tropical Forest Products 4(2): 192-198.
• Makino, M. & Fujimoto, Y., 1999. Flavanones from Baeckea frutescens. Phytochemistry 50(2): 273-277.
• Satake, T., Kamiya, K., Saiki, Y. & Hama, T., 1999. Chromone C-glycosides from Baeckea frutescens. Phytochemistry 50(2): 303-306.

Other selected sources

• [135] Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. Revised reprint. 2 volumes. Ministry of Agriculture and Co-operatives, Kuala Lumpur, Malaysia. Vol. 1 (A—H) pp. 1—1240, Vol. 2 (I—Z) pp. 1241—2444.
• [207] Corner, E.J.H., 1988. Wayside trees of Malaya. 3rd Edition. 2 volumes. The Malayan Nature Society, Kuala Lumpur, Malaysia. 774 pp.
• [252] Dharma, A.P., 1981. Indonesische geneeskrachtige planten [Indonesian medicinal plants]. De Driehoek, Amsterdam, the Netherlands. 168 pp.
• [264] Doan Thi Nhu, Nguyen Thuong Thuc, Do Huy Bich & Vu Thuy Huyen (Editors), 1990. Les plantes médicinales au Vietnam. Livre 1. Médicine traditionelle et pharmacopée [The medicinal plants of Vietnam. Volume 1. Traditional medicine and pharmacopoeia]. Agence de coopération Culturelle et Technique, Paris, France. 201 pp.
• [407] Heyne, K., 1950. De nuttige planten van Indonesië [The useful plants of Indonesia]. 3rd Edition. 2 volumes. W. van Hoeve, 's-Gravenhage, the Netherlands/Bandung, Indonesia. 1660 + CCXLI pp.
• [730] Ng, F.S.P., 1991—1992. Manual of forest fruits, seeds and seedlings. 2 volumes. Malayan Forest Record No 34. Forest Research Institute Malaysia, Kepong, Malaysia. 997 pp.
• [739] Nguyen Van Duong, 1993. Medicinal plants of Vietnam, Cambodia and Laos. Mekong Printing, Santa Ana, California, United States. 528 pp.
• [788] Pételot, A., 1952—1954. Les plantes médicinales du Cambodge, du Laos et du Vietnam [The medicinal plants of Cambodia, Laos and Vietnam]. 4 volumes. Centre National de Recherches Scientifiques et Techniques, Saigon, Vietnam.
• [1017] Tsui, W.Y. & Brown, G.D., 1996. Chromones and chromanones from Baeckea frutescens. Phytochemistry 43(4): 871—876.
• [1018] Tsui, W.Y. & Brown, G.D., 1996. Sesquiterpenes from Baeckea frutescens. Journal of Natural Products 59(11): 1084—1086.
• [1066] Whitmore, T.C. & Ng, F.S.P. (Editors), 1972—1989. Tree flora of Malaya. A manual for foresters. 2nd Edition. 4 volumes. Malayan Forest Records No 26. Longman Malaysia Sdn. Berhad, Kuala Lumpur & Petaling Jaya, Malaysia.
• [1091] Xiang, Z.X., He, X.Q., Zhou, G.F.& Li, C.H., 1983. Studies on the effect of essential oil of Gangsong (Baeckea frutescens L.) against liver injury in mice. Yao Hsueh Hseuh Pao 18(9): 654—659. (in Chinese)

Authors

• Umi Kalsom Yusuf