If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.




Dolphins love coral; male mice hate bananas

by Laura Howes
June 16, 2022 | A version of this story appeared in Volume 100, Issue 22


Cetacean skin care

Dolphins swimming past a coral.
Credit: Angela Ziltener
Marine medication: A mother dolphin teaches her calf how to apply coral to its skin.

If you dive down into the skin-care aisles in search of a new moisturizer, you’ll often find products boasting marine-derived chemicals. Seaweed, microalgae, and marine collagen are just some ingredients that have moved from the sea to terrestrial skin care. But what about the ocean’s inhabitants? How do they keep their skin supple, smooth, and fungi-free? The answer, at least for dolphins, seems to lie in corals. Or, more strictly, a chemically packed mucus the coral polyps produce (iScience 2022, DOI: 10.1016/j.isci.2022.104271).

As C&EN has reported in the science concentrates pages, corals and sponges produce a wealth of bioactive compounds. In 2009, Angela Ziltener, a wildlife biologist at the University of Zurich, and her team observed the Indo-Pacific bottlenose dolphins rubbing against corals and sponges. This behavior happens regularly and is passed down from adults to young. Perhaps, the team reasoned, the dolphins were applying coral and sponge-produced natural products to cure or prevent skin problems.

After receiving samples from the marine life involved, a team of analytical chemists led by Gertrud Morlock at Justus Liebig University Giessen helped Ziltener and coworkers by separating the active ingredients in the marine mucus and testing them to find out their chemical identities and what biological activity they have. In total, they found 17 different biologically active substances: 10 were antimicrobial, while others were antioxidants or hormones.

Unfortunately, the researchers did not get enough of the active compounds from the samples to apply them onto dolphin skin to measure how they work in sea-tu. But the marine mammals will even queue up and wait for their turn at the coral and sponge undersea skin-care spa, suggesting they believe there’s something good to the marine skin-care regime.

Dolphins are intelligent, but they do lack the lab space we might expect for brewing up new skin-care formulations. Instead, Ziltener has noticed that the dolphins seem to match different corals to specific body parts. The dolphins use soft corals for whole-body applications and rub their head region and ventral side against leather corals and sponges, sometimes even ripping out sections to wave around.

For those of us on land, skin care is best left to cosmetic chemists, but keeping corals and sponges safe in the sea might also help the skin health of our aquatic dolphin friends.


Banana anxiety

A drawing of a fearful mouse next to a giant banana.
Credit: Yang H. Ku/C&EN/Shutterstock
Peee-ew: The smell of bananas makes male mice fearful.

Bananas are a universally beloved snack, right? Apparently not. Researchers at McGill University led by Jeffrey Mogil discovered that male mice won’t thank you for a piece of banana. In fact, the idea—or rather smell—will completely stress them out. The chemical culprit is the ester n-pentyl acetate (Sci. Adv. 2022, DOI: 10.1126/sciadv.abi9366).

The team made the discovery when they realized that lactating female mice were sending out a chemical signal in their urine to tell males to back off and leave their babies alone. The next step was to identify the chemical that the females were using, which was when the McGill team found n-pentyl acetate in the females’ pee.

Murine micturition molecule discovered, they then looked for other sources to see if they could replicate the effect. And that led them to bananas, a natural source of n-pentyl acetate. The scientists found that the stress hormones in male mice peaked after a cotton ball soaked in banana oil was added to the mice’s cage, just like it did when the male mice smelled the females’ urine. You could say the smell made the male mice . . . go bananas.

Please send comments and suggestions to


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.