Chemical composition of the plant

This is a discussion paper. It does not reflect the views of the Committee. It should not be cited.

28.             The pericarp of G. cambogia Desr., contains 10 to 30% organic acids, calculated as citric acid equivalents, including less than 1% citric, oxalic, tartaric, and acetic acids; more than 4% malic acid; and up to over 15% HCA. It was identified that other Garcinia ssp., also contained HCA though typically at lower levels.

29.             HCA (C6H8O8) is a derivative of citric acid that has an additional hydroxyl group on the second carbon, creating two chiral centres at positions C-2 and C-3. HCA exists as four stereoisomers: (-)-HCA (2S,3S), (+)-HCA (2R,3R), (+)-allo-HCA (2S,3R) et (-)-allo-HCA (2R,3S).

30.             In G. cambogia Desr., this compound [HCA] appears in the (2S,3S) or (-)-HCA configuration and serves as a competitive inhibitor of ATP-citrate lyase, an enzyme that drives fatty acid synthesis. Each stereoisomer can cyclise to a γ-lactone. In G. cambogia Desr., HCA occurs in both its non-lactonic form and its lactonic form, known as garcinia lactone or (2S,3S)-3-hydroxy-5-oxo-2,3,4,5-tetrahydrofuran-2,3-dicarboxylic acid. From the literature, it was described that the lactonic form of (2S,3S)-HCA inhibits ATP citrate lyase less effectively than the non-lactonic form. It is also less bioavailable.

31.             Industrial processes generally stabilise HCA as a single, double, or triple salt to prevent its cyclisation into the lactone form. The most common are calcium, magnesium, or potassium salts because they offer greater stability, higher solubility, and lower hygroscopicity compared to sodium salts.

32.             The fruit of G. cambogia Desr., contains 6.25% carbohydrates, 3.25% protein, less than 0.0060% amino acids, and 0.34% lipids. The dried pericarp of G. cambogia Desr., contains 14.4 mg vitamin C. The bark has also been reported to contain certain B-group vitamins: 48 μg vitamin B1, 275 μg vitamin B2, 45 μg vitamin B3 and 8.8 μg vitamin B12 per 100 g. The dried fruit bark also contains minerals: 2.8 mg sodium, 26.6 mg potassium, 12.7 mg calcium, 14.4 mg magnesium, 9 mg iron and 5.3 mg phosphorus per 100g.

33.             G. cambogia Desr., has been described to contain polyisoprenylated benzophenones (precursors of xanthones). Studies have isolated garcinol, isogarcinol from the plant’s bark and fruit. Both compounds have been shown to have antitumour, antimicrobial, antioxidant, anti-inflammatory, and central nervous system effects, especially in vitro and in animal models. Other isolated polyisoprenylated benzophenones are presented in the ANSES Opinion.

34.             The xanthone content of the fruit was estimated to be 1.96%. The total phenol content is estimated to be 3.26%. Flavone heterosides (apigenin, luteolin) and flavanols (kaempferol, quercetin) have been detected in G. cambogia Desr., fruits.

35.             Glycosylated derivatives of caffeic acid (caffeoyl glucose), esterified with quinic acid (dicaffeoyl-quinic acid) as well as p-coumaroyl-quinic acid have also been detected in fruits.