Lupane (compound)

Lupane is a pentacyclic triterpene hydrocarbon with the molecular formula C₃₀H₅₂. It serves as the core skeleton for various bioactive compounds, including lupeol and betulinic acid, which are prevalent in numerous plant species.^[1] It actually features a structure composed of five fused rings––four cyclohexane rings and one cyclopentane––and is one of the major triterpene skeletons alongside hopane, oleanane, and ursane types. The compound is common in birch bark.

Lupane

Names
IUPAC name (1S,3aR,5aR,5bR,7aS,11aS,11bR,13aR,13bR)-3a,5a,5b,8,8,11a-Hexamethyl-1-propan-2-yl-1,2,3,4,5,6,7,7a,9,10,11,11b,12,13,13a,13b-hexadecahydrocyclopenta[a]chrysene
Identifiers
CAS Number	464-99-3
3D model (JSmol)	Interactive image
Beilstein Reference	2562721
ChEBI	CHEBI:36485
ChemSpider	2340755
PubChem CID	9548715
CompTox Dashboard (EPA)	DTXSID40963569
InChI InChI=1S/C30H52/c1-20(2)21-12-16-27(5)18-19-29(7)22(25(21)27)10-11-24-28(6)15-9-14-26(3,4)23(28)13-17-30(24,29)8/h20-25H,9-19H2,1-8H3/t21-,22+,23-,24+,25+,27+,28-,29+,30+/m0/s1 Key: NKMDIWKRKQFYPH-VIUFNMEASA-N
SMILES CC(C)[C@@H]1CC[C@]2([C@H]1[C@H]3CC[C@@H]4[C@]5(CCCC([C@@H]5CC[C@]4([C@@]3(CC2)C)C)(C)C)C)C
Properties
Chemical formula	C30H52
Molar mass	412.746 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Occurrence and derivatives

Derivatives of lupane, such as lupeol, betulin, and betulinic acid, are found in high concentrations in birch bark (Betula spp.), mango peels, olives, strawberries, and other fruits.^[2]

Similar derivatives

Similar derivatives are the following ones:

• Lupeol (C₃₀H₅₀O) – a hydroxylated lupane at position C‑3, with noted anti-inflammatory and anti‑cancer effects.
• Betulin (C₃₀H₅₀O₂) – a diol lupane naturally abundant in birch bark (up to 30% by dry weight) and researched for wound healing and pharmaceutical uses.^[3]
• Betulinic acid – the oxidized carboxylic acid form of betulin; one of the most extensively studied lupane-derived compounds with anticancer activity.^[4]

Biosynthesis and uses

Like all triterpenes, lupane is biosynthesized via cyclization of the squalene precursor in plants and fungi.

While lupane itself has limited direct applications, its derivatives have been used in topical wound-healing formulations and are under evaluation as nutraceuticals and anticancer agents. Betulin-rich extracts are utilized in dermatology.

Biological activity

Pentacyclic lupane derivatives have attracted attention for potential pharmacological effects—including anti-inflammatory, antiviral, hepatoprotective, and anticancer activities—with generally low toxicity.^[5][6] Lupane-type molecules have been shown to modulate apoptosis and cell signaling in various cancer cell lines.

Recent studies highlight:

• Antiproliferative and anti-inflammatory effects of 3,4‑seco‑lupane derivatives from Eleutherococcus sessiliflorus.^[7]
• Lupane-triterpene-tryptamine hybrids demonstrating potent anti‑bladder cancer activity through modulation of DUSP5 and the p38 MAPK pathway.
• Lupane-based analogs with inhibitory activity toward influenza A (H1N1).

See also

• Triterpene
• Lupeol
• Betulin
• Betulinic acid