Punicalin

Punicalin is a hydrolyzable tannin (an ellagitannin) identified in Punica granatum, commonly known as pomegranate. It occurs in the fruit peel and juice and is often described as one of the major ellagitannins in pomegranate, typically alongside punicalagin. Structurally, punicalin is a polyphenolic glucose derivative bearing complex ellagitannin units; when hydrolyzed, punicalin yields ellagic acid and glucose.

In food and nutrition contexts, punicalin contributes to the astringency and antioxidant capacity of pomegranate products. Its presence helps explain part of the polyphenol profile that characterizes pomegranate extracts used in research and nutraceuticals. The compound is of interest not only for sensory properties but also for its potential biological activities.

Bioactivity studies have investigated punicalin’s antioxidant and anti-inflammatory properties, primarily in vitro and in animal models. These studies suggest that ellagitannins, including punicalin, may modulate oxidative stress and inflammatory pathways; however, evidence from human studies remains limited and inconclusive. The bioavailability of punicalin depends on gut microbiota, with hydrolysis and metabolism leading to ellagic acid derivatives that can be further transformed into urolithins, which may contribute to systemic effects.

Analytically, punicalin is commonly quantified in pomegranate extracts by high-performance liquid chromatography (HPLC), often alongside punicalagin, to assess total ellagitannin content. While primarily associated with pomegranate, related ellagitannins are found in other fruits and nuts, but punicalin is most closely linked to Punica granatum.