Rutin

Rutin, also called rutoside or sophorin, is the flavonol glycoside quercetin-3-O-rutinoside, CAS 153-18-4, molecular formula C27H30O16 with a molar mass of 610.52. It is normally traded as the trihydrate, CAS 250249-75-3, molecular formula C27H30O16.3H2O and molecular weight 664.56, which is why an NF-grade certificate shows a loss on drying limit as high as 9.0% while still meeting a 95% assay. The compound takes its name from Ruta graveolens but is not sourced from it commercially. Thovek supplies rutin extracted from the dried flower buds of Styphnolobium japonicum, still widely traded under the older name Sophora japonica, which is by a wide margin the richest and most economic industrial source. The standard commercial article is Rutin NF11, assay not less than 95.0% by UV, appearing as a yellow to greenish-yellow crystalline or fine powder with total ash not more than 0.5% and loss on drying not more than 9.0%. A 98% HPLC grade is available where a tighter flavonoid profile is required, and rutoside trihydrate meeting the European Pharmacopoeia monograph can be supplied against a written pharmacopoeial specification. Solubility is the main formulation constraint: rutin is practically insoluble in water, sparingly soluble in ethanol 96% and soluble in methanol, so tablets, capsules and dry premixes are the natural dosage forms, while beverage work generally calls for a solubilised or enzyme-modified derivative such as an isoquercitrin-type material rather than rutin itself. Two commercial points are worth flagging. First, allergen origin. Rutin is also recoverable from buckwheat, Fagopyrum esculentum, and buckwheat is a mandatory declarable allergen in Japan and a labelled allergen in Korea. Material offered by Thovek is from Styphnolobium japonicum flower buds, not buckwheat, so no buckwheat declaration is triggered; if your programme requires buckwheat-origin rutin we will say so explicitly on the specification rather than let the origin be assumed. Styphnolobium is a legume genus, but the article is a purified glycoside from flower buds, not a peanut, soy or lupin derivative, and carries none of those allergens. Second, the material is wholly plant-derived with no animal-origin processing aid, so it supports vegan, vegetarian, halal and kosher positioning. Every lot ships with assay, loss on drying, ash, heavy metals, residual solvent and microbiological results.