Molecular voyages of discovery in the world of perfume

{"text":[[{"start":9.02,"text":"In Herman Melville’s 1851 novel Moby-Dick, the crew of the whaling ship Pequod discover a yellow cheese-like substance lodged inside the intestines of a dying sperm whale. They quickly learn that the material is ambergris, the “grey gold” of perfumery coveted since ancient times for its musky, marine-like odour."}],[{"start":24.28,"text":"“Who would think, then, that such fine ladies and gentlemen should regale themselves with an essence found in the inglorious bowels of a sick whale!” exclaims Stubb, second mate of the Pequod."}],[{"start":34.64,"text":"Today, millions of ladies and gentlemen “regale” themselves with ambrox — also known as ambroxan — one of the primary molecules in ambergris responsible for its alluring aroma. First synthetically reproduced in 1950, the molecule now appears in perfumes as ubiquitous as Drakkar Noir, Maison Francis Kurkdjian’s Baccarat Rouge 540 and Frédéric Malle’s Portrait of a Lady. Parfums Christian Dior claims that its ambrox-laden Sauvage sells one bottle every 30 seconds."}],[{"start":63.76,"text":"Until recently, however, understanding which olfactory receptors in the nasal cavity are triggered by ambrox, and many other popular aroma molecules, remained the proverbial elusive Moby-Dick for scientists looking to unlock the mysteries of the human nose."}],[{"start":78.76,"text":"“To understand the dimensions of olfaction, that’s the holy grail,” says Andreas Natsch, senior research fellow at Swiss fragrance manufacturer Givaudan."}],[{"start":87.92,"text":"It has long been known that the human nose contains roughly 400 olfactory receptors to which odour molecules may then bind in a “lock and key” configuration and send signals to the brain — the odour molecule is the ‘key’ that ‘unlocks’ the sense of smell. But the vast majority of receptors remain unmapped or “orphaned” from the corresponding scent molecule or molecules that activate them."}],[{"start":109.68,"text":"In 2025, however, Natsch and a team of scientists working at Givaudan pinpointed two olfactory receptor genes which respond to ambrox. Until then it was assumed that interaction with a broad pattern of receptors was essential for an odour molecule to trigger a scent reaction. In findings published in the journal Current Biology, Natsch and his team discovered that the interaction of ambrox with just one receptor gene was enough to trigger a woody fragrance sensation; and in the other, the warm amber scent of aged ambergris."}],[{"start":141.96,"text":"As well as ambrox, research by Givaudan identified an active relationship between 19 other popular odour molecules, including the roselike citronellol and geraniol, and a corresponding receptor."}],[{"start":154.64,"text":"“Somehow, we knew that from the perfumer’s experience, from the success of those perfumes, and from the usage of those perfumes, that there was something special. But we didn’t have the words,” Natsch says of the popularity of ambrox in modern perfumery. “Now we can explicitly find out why that is the case . . . we can bring together the biology with this deep perfumery knowledge.”"}],[{"start":176.32,"text":"For Natsch, the ability to predict which olfactory receptors will be triggered by particular odour molecules opens the door to a future where perfumers can be guided not merely by intuition, but by foreknowledge of how the human nose will react to the raw materials at their disposal."}],[{"start":191.08,"text":"“I think we are in the beginning of a revolution of how we understand scent and how we understand these dimensions,” says Natsch, who also predicts potentially far-reaching consequences for how new molecules are developed. “It certainly helps in the molecule design and in really discriminating these different nuances,” says Natsch."}],[{"start":210.76,"text":"For most of human history, perfumers worked intuitively, building compositions layer by layer, determined by the size, weight and volatility of the molecules involved — from heavy notes such as ambergris in the base, rich florals in the heart and more fleeting, effervescent citrus-like notes at the top."}],[{"start":null,"text":"

"}],[{"start":227.36,"text":"One perfumer who is very familiar with the spellbinding properties of ambrox is perfumer Andy Tauer, who founded Zurich-based Tauer Perfumes in 2005. It has since become a personal signature, featuring in more than half the 46 perfumes he has released. In compositions including his 2006 leather fragrance, Lonestar Memories, to his most recent composition, the floral green L’Aur du Jardin Caché, otherwise fleeting odour molecules can be given a performance boost by the blending of ambrox."}],[{"start":257.92,"text":"“It’s like a superglue,” Tauer says of ambrox, speaking from his Zurich laboratory. “It makes everything stick together and stay on your skin. And from that point of view, it’s very versatile.”"}],[{"start":269.08,"text":"For Tauer, the implications of increased receptor-to-molecule mapping lie not only in how a perfumer can build a composition by anticipating the exact receptors each molecule may activate but also in the new molecules yet to be synthesised."}],[{"start":290,"text":"“Increasing the ‘noise to signal’ [molecule to receptor] ratio will help us to find new molecules,” says Tauer. “To find new molecules that are interesting, for instance, as a complement for ambroxan or as an enhancer: ‘Maybe I will need to get something to react even stronger to that receptor’.”"}],[{"start":300.88,"text":"Although scientists are mapping the human nose-to-odour molecules with ever more precision, the larger question of exactly how these molecules send signals to the brain of, say, family, friends or lovers remains largely unresolved."}],[{"start":313.52,"text":"In his 2007 book, The Secret of Scent, perfume critic and biophysicist Luca Turin furthered a theory of olfaction by which odour molecules send signals to the brain through a process of vibration."}],[{"start":325.6,"text":"While today he believes the vibrational theory can coexist with the “lock and key” model, for Turin the true power of perfumery lies not in science or engineering, but in its ability to communicate the sublimity of nature through the beauty of artistic creation."}],[{"start":340.08,"text":"“There’s a gradient between a smell and a fragrance, in which the amount of human intervention and choice increases as you go from smell to fragrance,” Turin says."}],[{"start":348.28,"text":"“Rose or ambergris or musk is sublime. It’s an untouched, miraculous thing that nature has put out there, like mountains and clouds. As you go towards perfume, it really becomes a much more intentional kind of beauty. That is a message from one person to another.”"}],[{"start":367.4,"text":""}]],"url":"https://audio.ftcn.net.cn/album/a_1793370165_2591.mp3"}