Decalepis hamiltonii Wight & Arn. - Apocynaceae - swallowroot, Makali beru (kannada), Makali durga (kannada), magali kizhangu (tamil), **Indische Schwalbenwurz**

Climbing shrub, endemic to Peninsular India, listed as endangered; roots fleshy and tuberous with a sweet, vanilla-like fragrance. \\
[Sharma, Shiwali, and Anwar Shahzad. "An overview on Decalepis: a genus of woody medicinal climbers." J Plant Sci Res 1.1 (2014): 104] [[https://www.opensciencepublications.com/fulltextarticles/JPSR-2349-2805-1-104.pdf|PDF]] \\
[[https://efloraofindia.com/efi/decalepis-hamiltonii/]]

"Decalepis hamiltonii root has a strong aromatic odour and its volatiles possess antimicrobial and insecticidal properties. On steam distillation the fresh fleshy roots yielded a volatile oil (0.68%) from which 2-hydroxy-4-methoxybenzaldehyde crystallized out (96%). GC–MS analysis of the oil showed, besides the residual major component, the presence of benzaldehyde (0.017%), salicylaldehyde (0.018%), methyl salicylate (0.044%), benzyl alcohol (0.016%), 2-phenylethyl alcohol (0.081%), ethyl salicylate (0.038%), p-anisaldehyde (0.01%), and vanillin (0.45%), which are minor but significant, olfactorily and biologically." \\
[Nagarajan, S., L. Jagan Mohan Rao, and K. N. Gurudutt. "Chemical composition of the volatiles of Decalepis hamiltonii (Wight & Arn)." Flavour and Fragrance journal 16.1 (2001): 27-29]

{{:4methoxysalicylaldehyde.png|4-methoxysalicylaldehyde}} 2‐hydroxy‐4‐methoxybenzaldehyde (//vanillin-like//)

"Hydrodistillation of Decalepis hamiltonii roots yielded an essential oil (0.33% v/w) that contained 2-hydroxy-4-methoxybenzaldehyde (37.45%), 2-hydroxybenzaldehyde (31.01%), 4-O-methylresorcylaldehyde (9.12%), benzyl alcohol (3.16%), and α-atlantone (2.06%) as major constituents, with aromatic aldehydes constituting the main fraction of this root's essential oil." \\
[Thangadurai, Devarajan, et al. "Essential oil constituents and in vitro antimicrobial activity of Decalepis hamiltonii roots against foodborne pathogens." Journal of Agricultural and Food Chemistry 50.11 (2002): 3147-3149]

"The roots of Decalepis hamiltonii and [[hemidesmus_indicus_l._w.t.aiton|Hemidesmus indicus]] are aromatic and possess the crystalline compound 2-hydroxy-4-methoxybenzaldehyde as the major compound (>90%) in their volatile oils... The quantity of this aromatic compound varied from 0.03 to 0.54%" \\
[Nagarajan, Subban, and Lingamallu Jagan Mohan Rao. "Determination of 2-hydroxy-4-methoxybenzaldehyde in roots of Decalepis hamiltonii (Wight & Arn.) and Hemidesmus indicus R. Br." Journal of AOAC International 86.3 (2003): 564-567]

2-Hydroxy-4-methoxybenzaldehyde, also extracted from Decalepis hamiltonii, [[hemidesmus_indicus_l._w.t.aiton|Hemidesmus indicus]] or [[periploca_sepium_bunge|Periploca sepium]], is used to improve, enhance, or modify the vanilla flavour profile of a composition. Firmenich patent (2026) [[https://patents.google.com/patent/US20260101914A1/en|US20260101914A1]]  

{{:decalepis_hamiltonii.jpg?600|}} \\
Decalepis hamiltonii, Telangana, India (2026) © Kobita Dass Kolli [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]] [[https://www.inaturalist.org/observations?taxon_id=498320|inaturalist.org]]