Botany
Rambutan is an evergreen, bushy tree, growing to a height of 20 meters, with a dense, low, round and spreading crown. Leaves are pinnately compound, 15 to 40 centimeters long, with 3 to 8 leaflets. The leaflets are elliptic, 7.5 to 20 centimeters long, and 3.5 to 8 centimeters wide. Flowers are greenish white, fragrant, very small, without petals, and borne on axillary panicles. Fruit is oblong, 4 to 5 centimeters long, red to yellow, covered with thick, coarse hairs or soft spines. Pulp is edible, white, opaque, translucent, juicy and sweet.

Distribution
- Cultivated in most parts of the Philippines.
- Also reported in India to Indo-China and Malaya, and extensively cultivated in Java and Malaya.

Parts utilized:
Roots, leaves and bark.

Constituents
• Seeds yield 40-48 % rambutan tallow. The insoluble fatty acids of the tallow contain about 45 percent oleic acid. The tallow contains abundant arachin, some stearin and olein.
- The seeds have traces of an alkaloid, sugar 1.25%, starch 25%, and ash 2%.
- Flesh or pulp of the fruit yields saccharose 7.8^%, dextrose 2.25%, levulose 1.25%,
- Fruit contains fat 35%, ash 2%, vitamin C 4%.
- The shoots yield saponin.
- The testa of the seed is toxic due to the presence of Nephelium saponin and tannin.
- The testa o

Properties
• Fruit is considered astringent, stomachic, vermifuge, febrifuge.
- Seeds reported as bitter and narcotic.

Uses
Folkloric
- The Malays use a decoction of roots for fevers; the leaves for poulticing, and the bark as astringent for diseases of the tongue.
- Fruit decoction used for diarrhea and dysentery.
- Edible pulp (aril) is used as an refrigerant in fevers.
- In China, fruit is recommended for severe dysentery, and as a warm carminative in "cold" dyspepsia.
- In Malaya, astringent bark is used as remedy for thrush. Decoction of roots taken as febrifuge. source
Others
Elsewhere, seed used to extract oil; also roasted and eaten.

Studies
• Antioxidant / Antibacterial: Study yielded high amounts of phenolic compounds in the peel extracts, highest in the methanolic extract, exhibiting higher antioxidant activity than the seed extracts. All peel extracts exhibited antibacterial activity against five pathogenic bacteria.
• Phytochemicals / Monoterpene Lactones: Study isolated two new diasteromeric monoterpene lactones 1 and 2. Both underwent antimicrobial testing.
• Antioxidant in Rinds: The normally discarded rind was found to have extremely high antioxidant activity. The study of the extract revealed high phenolic content, low pro-oxidant capacity and strong antioxidant activity with cosmetic, nutraceutical and pharmaceutical potentials.
• Antiviral / Anti-Herpes: Tested for anti HSV-1 virus activity, N lappaceum significantly affected the development of skin lesions and reduced mortality.
• Cancer Chemopreventive / Waste Product: Study of NL extract showed an antiproliferative effect associated with apoptosis. The extract induced G2/M arrest of HOS indicating inhibition of cell cycle progression as one of the mechanisms. Extract was non-cytotoxic to normal cells at its inhibitory concentration. The study showed a potential for the rind, an underutilized waste product of Nephelium lappaceum.|
• Antioxidant in Peels / Elliagitannins: The methanolic extract of NL peels exhibited strong antioxidant properties. Study isolated ellagic acid, corilagin, and geraniin. The ellagitannins, principal components of rambutan peels present as potential for utilization in both food and medical industry.
• Fatty Acid Synthase / Potential Cancer and Obesity Therapeutics: Natural products inhibiting fatty acid synthase are potential therapeutic agents to treat cancer and obesity. Study isolated 10 compounds in NL, including flavonoids and oleane-type triterpene oligoglycosides. Compounds 8 and 9 were hederagenin derviatives. The isolates showed inhibitory activity against FAS. Results suggest the hulls of NL may be a potential source of promising FAS inhibitors .
• Anthocyanins / Antioxidant: Anthocyanins, known to possess high antioxidant activity, were extracted from rambutan pericarp tissue. However, the pericarp tissue is usually discarded as waste. Results suggest a potential for extraction of health-beneficial bioactive compounds such as anthocyanins, with potential benefit to the rambutan industry.
• Seed and Seed Oil / Physiochemical and Nutritional Composition: Seeds were found abundant in fats (38.(%), protein (12.4%), carbohydrate (48%). Seed oil yielded oleic acid (40.45%) and arachidic acid (36.36%) as major fatty acid. Results showed rambutan seed is a potential source of oil or carbohydrate for the human diet and for food product application.
• Anti-Hyperglycemic / Geraniin: Study described rapid isolated of geraniin. In addition to high antioxidant activity and low pro-oxidant capability, geraniin showed in vitro hypoglycemic activity and aldol reductase inhibition activity, and was able to prevent the formation of advanced glycation end-products. Results support the used of a geraniin-standardized N. lappaceum extract for the management of hyperglycemia.
• Seed Waste as Source of Fat: Study reported that the seed kernel of rambutan, a product generally considered waste material, can be used as a sustainable source of fats. Seed kernels yield a considerable amount of fat and high arachidic acid that makes the fat highly stable to oxidation, and a potential source of industry fats.
• Ellagitannins / Antioxidant: Study isolated ellagitanins (1) ellagic acid (2) corilagin and (3) geraniin. Geraniin was the major component, exhibiting much greater antioxidant activities than BHT in both lipid peroxidation and DPPH assay. Results suggest use of the isolated ellagitannins from the peels for both medicine and food industry.

Availability
Cultivated.