Which purine base makes up most of this number?

Hypoxanthine — 129 mg of the 157.2 mg per 100 g total. The rest is adenine 17.6, guanine 10.6, xanthine 0.

Is this value for raw or cooked food?

Raw — the source entry is Tuna, raw (unspecified). Cooking changes water content, so compare like with like.

Why is hypoxanthine the largest fraction here?

Hypoxanthine accounts for 129 of the 157.2 mg total — about 82% of the number.

Tuna, raw (unspecified)

Moderate purine

Finfish and shellfish

Purine content

157 mgper 100 g

The level label is a plain categorization of the number above — not a statement about whether this food fits your diet. See the full disclaimer.

Composition — per 100 g

Purine, total	157 mg
— Adenine	17.6 mg
— Guanine	10.6 mg
— Hypoxanthine	129 mg
— Xanthine	0 mg
Fructose	No data available
Calories	144 kcal

Missing figures are shown as “No data available”; values are copied from the sources below and are never estimated. Laboratory values differ between studies and samples.

Where these numbers come from

Purine total and fractions: Kaneko, K., et al. (2014). Total purine and purine base content of common foodstuffs for facilitating nutritional therapy for gout and hyperuricemia. Biological and Pharmaceutical Bulletin, 37(5), 709-21..
Fructose and calories: USDA FoodData Central record #173706.

If you want something similar

Within finfish and shellfish, the same table also lists Oysters, canned at 107 mg and Cod, Atlantic, wild, raw at 110.3 mg per 100 g.

From the author

Personal experience of someone living with gout

I skip it during a flare; outside one it's part of my protein rotation.

Personal experience — not medical advice. Read the full disclaimer.

Questions

Which purine base makes up most of this number?: Hypoxanthine — 129 mg of the 157.2 mg per 100 g total. The rest is adenine 17.6, guanine 10.6, xanthine 0.
Is this value for raw or cooked food?: Raw — the source entry is Tuna, raw (unspecified). Cooking changes water content, so compare like with like.
Why is hypoxanthine the largest fraction here?: Hypoxanthine accounts for 129 of the 157.2 mg total — about 82% of the number.

Looking for a different food? Search the full database — every entry there links back to its source, whether or not it has a page like this one. Or browse moderate purine foods.