India (Southern India — Tamil Nadu, Karnataka, Kerala, Andhra Pradesh)
Pyramid
Heart
Sweet, vanillic, faintly anisic. The smell of splitting open a sun-dried root and finding crystallised vanilla inside — except warmer, less green, and with a soft medicinal edge. The key molecule is 2-hydroxy-4-methoxybenzaldehyde, a structural isomer of vanillin that occurs at 96 percent of the root volatile oil.
Sweet and vanillic but distinctly not vanilla. The dominant note is anisic — clean, phenolic-sweet, with a dry medicinal transparency that vanilla lacks. Where vanillin smells round, warm, and caramellic, the Decalepis root compound (2-hydroxy-4-methoxybenzaldehyde) is flatter, sharper, more linear. A faint salicylate wintergreen edge sits underneath, contributed by trace methyl salicylate in the volatile oil. The overall impression is of a vanilla that has been stripped of its gourmand richness and replaced with something cooler and more austere — closer to tonka bean's coumarin quality than to cured vanilla pod.
Evolution over time
Immediately
Immediately
Sweet, anisic, lightly medicinal. 2-Hydroxy-4-methoxybenzaldehyde at full strength — vanilla-adjacent but drier and more phenolic, with a faint wintergreen edge from trace methyl salicylate
After a few hours
After a few hours
The anisic sharpness softens. A warm, powdery sweetness emerges — less caramellic than vanillin, more resinous. Faint balsamic undertones from minor aldehyde constituents
After a few days
After a few days
Soft, warm, faintly sweet residue. The medicinal edge has dissipated entirely. What remains is a clean, dry vanilla-adjacent warmth with low sillage
Terroir & Post-Harvest Process
Indicative 2025 wholesale prices.
The Full Story
Decalepis hamiltonii Wight & Arn. is a woody perennial climber endemic to the Eastern and Western Ghats of peninsular India, classified in the Apocynaceae (subfamily Periplocoideae, formerly Asclepiadaceae). The plant produces clusters of fleshy, tuberous roots that carry a striking vanilla-like aroma — not from vanillin itself, but from its positional isomer, 2-hydroxy-4-methoxybenzaldehyde (2H4MB, CAS 673-22-3). Steam distillation of the fresh roots yields a volatile oil at 0.68%, from which 2H4MB crystallises out at 96% concentration (Nagarajan et al., Flavour and Fragrance Journal, 2001). The remaining 4% includes benzaldehyde (0.017%), salicylaldehyde (0.018%), methyl salicylate (0.044%), benzyl alcohol (0.016%), 2-phenylethyl alcohol (0.081%), and vanillin (0.45%).
The odor is sweet, warm, and vanillic but not identical to vanilla. Where vanillin (4-hydroxy-3-methoxybenzaldehyde) is caramellic and round, 2H4MB is drier, more anisic, with a faint phenolic-medicinal edge that recalls the clean sweetness of anise seed rather than the gourmand richness of cured vanilla pods. The distinction is subtle but consistent: sniffed side by side, the Decalepis root reads as thinner, sharper, more linear than vanilla — a line drawing versus an oil painting.
Conservation and Sourcing
Decalepis hamiltonii is classified as Endangered on the IUCN Red List. Harvesting is destructive — the entire plant must be uprooted to access the tuberous roots, and wild populations across Karnataka, Tamil Nadu, Kerala, and Andhra Pradesh have declined severely. Cultivated sources exist (notably in the Mysore and Madurai districts), and agricultural programmes aim to reduce pressure on wild populations. The root is traded locally under regional names: makali beru or vagani beru in Kannada, magali kizhangu in Tamil, maredu kommulu or nannari kommulu in Telugu. It is used to prepare nannari sharbat (a traditional South Indian sweet drink), pickles, and Ayurvedic preparations.
Regulatory Status
The extract (CAS 853947-36-1) carries FEMA number 4283 and is classified as GRAS for food flavoring. TGSC designates it as a flavoring agent only — not for fragrance use. No IFRA Standard exists for this material. Its presence in perfumery databases reflects aromatic interest rather than established fragrance application.
2-Hydroxy-4-methoxybenzaldehyde, the molecule that gives Decalepis hamiltonii its vanilla-like aroma, is a positional isomer of vanillin — same atoms (C8H8O3), different arrangement. Vanillin is 4-hydroxy-3-methoxybenzaldehyde; the Decalepis compound swaps the hydroxyl and methoxy positions on the ring. This minor structural rearrangement shifts the odor from caramellic-vanilla toward anisic-medicinal. The FDA revoked food-use authorisation for the synthetic form of seven flavoring substances including this compound, though the natural occurrence in plant roots remains GRAS under FEMA 4283.
Extraction & Chemistry
Extraction method: Steam distillation of fresh fleshy roots yields a volatile oil at 0.68% (Nagarajan et al., Flavour and Fragrance Journal, 2001). The major component — 2-hydroxy-4-methoxybenzaldehyde — crystallises directly from the oil at 96% concentration. For absolute production, dried powdered roots are subjected to solvent extraction (hexane or ethanol), followed by evaporation of the solvent to yield a dark, resinous concentrate. Harvesting is destructive: the entire plant must be uprooted to access the tuberous roots, which is the primary driver of the species IUCN Endangered classification. Cultivated sources exist in Karnataka and Tamil Nadu, but wild harvesting from the Eastern and Western Ghats remains prevalent. The root bark contains the highest concentration of 2H4MB (approximately 74 mg per gram of dry tissue in the medullary portion).
Decalepis hamiltonii extract is classified by FEMA (number 4283) as a flavoring agent and is listed by TGSC as not for fragrance use. Its presence in perfumery glossaries reflects its aromatic interest rather than widespread formulation use. The root absolute offers a natural vanillin-isomer profile — sweet, anisic, lightly medicinal — that differs from standard vanillin or ethyl vanillin in both character and regulatory pathway. The dominant molecule, 2-hydroxy-4-methoxybenzaldehyde (CAS 673-22-3, MW 152.15, mp 41-43 C, bp 269-270 C), is structurally closer to anisaldehyde than to vanillin in its odor behavior: less caramellic, more phenolic-sweet, with a clean medicinal undertone. In flavor work, it functions as a modifier and sweetness enhancer. In fragrance-adjacent applications (room sprays, candles, potpourri where IFRA restrictions do not apply), the absolute provides a warm, gourmand base with natural provenance. The root also contains trace amounts of vanillin (0.45%), benzaldehyde, methyl salicylate, and 2-phenylethyl alcohol — a minor terpene-aldehyde palette that adds textural complexity to the dominant 2H4MB note.
