Nitroglycerin: Explosives, Nobel Inventions and a Surprising Heart Medicine

This Chemistry World episode explores nitroglycerin, a compound famous for its explosive power and equally notable as one of the first medicines to treat angina. The story follows its discovery, Nobel's innovations, dramatic factory accidents, and the drug’s modern mechanism as a nitric oxide–mediated vasodilator. It also highlights the NO signaling work that earned a Nobel Prize and touches on surprising modern applications.

• From pyroglycerine to dynamite: the evolution of a dangerous compound
• The medical turn: how a heart medicine emerged from an explosive chemical
• Nitric oxide as a signaling molecule and the NO-based therapies
• The Nobel link: science, invention and the prizes

Introduction and context

The episode from Chemistry World presents a narrative weaving together the dual life of nitroglycerin, a compound whose power lies as both an explosive and a medical treatment. The host frames the story as a journey through chemistry, history and medicine, centered on how a single compound countenances both destruction and healing. The discussion features input from Cambridge University chemist Peter Wather and references the long arc from its 1847 discovery to its role in modern pharmacology.

The explosive origins of nitroglycerin

Nitroglycerin was first prepared in 1847 by the Italian chemist Asanio Sobrero, who initially called it pyroglycerine. Sobrero carefully documented its extraordinary sensitivity and explosive potential, which made handling extremely dangerous. The substance quickly became central to the fortunes of Alfred Nobel, who developed practical methods to manufacture it and sought safer ways to use it for controlled blasting.

From blasting oil to dynamite

Nobel collaborated with his teachers and peers to refine nitroglycerin into a workable form for blasting. The patented blasting oil, a paste of nitroglycerin and black powder, proved far more effective than traditional black powder for rock blasting. But the hazards remained severe. A catastrophic explosion at Nobel’s Stockholm factory in 1864 killed five people, including his younger brother, underscoring the perils of handling nitroglycerin. Further accidents and ominous red fumes in 1865 at a New York hotel added to the mounting concerns and ultimately contributed to regulatory restrictions on blasting oil.

The invention of dynamite and its impact

Almost by chance Nobel discovered a safer way to stabilize nitroglycerin by absorbing it into earth to form a dry, workable paste that detonates only with a detonator. He named this new invention dynamite, drawing on the Greek word dynamis for power. Dynamite made blasting safe enough for widespread construction and mining, transforming industries that required rock blasting, but at the same time amplifying the potential for misuse and tragedy.

The medical use of nitroglycerin and the mechanism of action

Even during its early exploitation as an explosive, nitroglycerin began to be used as a medicine. Sobrero cautioned against tasting the compound due to headaches, but the medical community began to suspect it might offer relief for certain conditions when sufficiently diluted. In 1879 William Murrell published a Lancet report describing nitroglycerin as a remedy for angina pectoris. The drug became known today as glyceryl trinitrate, and it remains in use as a heart medication. The chemical works as a potent vasodilator via the production of nitric oxide, a signaling molecule in the cardiovascular system. The narrative notes the practical, patient-friendly forms such as Xanafil, a brand under which nitroglycerin is used to treat angina, and even mentions its unlikely appearance in condoms as a demonstration of its altering effects.

Nobel, nitric oxide signaling and the Nobel Prize

The podcast highlights a pivotal moment in physiology and pharmacology when scientists Firchcott, Ignaro and Murad were awarded the 1998 Nobel Prize in Physiology or Medicine for discoveries concerning nitric oxide as a signaling molecule in the cardiovascular system. The discussion emphasizes how the same molecule that mediates vasodilation also underpins a wide range of physiological processes. The host muses that Alfred Nobel would likely have approved of the evolving uses of this otherwise destructive compound, linking the history of nitroglycerin to the Nobel tradition of recognizing transformative science.

Historical anecdotes, safety, ethics and modern ubiquity

The episode recounts dramatic episodes from the era of nitroglycerin’s early industrial use, including accidents and the public's fear of high explosives. It also notes the shift toward safer medical applications and acknowledges how nitroglycerin has entered modern life in new contexts such as maternal medicines, vascular research, and even consumer products. The conversation frames nitric oxide as a crucial signaling molecule whose precise mechanisms remain a topic of ongoing research, illustrating how a compound can bridge disciplines and eras in science.

Closing reflections

Concluding with a nod to the enduring relevance of metal chemistry, medicine, and the power of chemical discovery, the podcast invites listeners to reflect on the intertwined history of chemistry and medicine and to anticipate future explorations in Chemistry in Its Element.