Proanthocyanidins from Spenceria ramalana and Their Effects on AGE Formation in Vitro and Hyaloid-Retinal Vessel Dilation in Larval Zebrafish in Vivo

• Published in: Journal of natural products (Washington, D.C.) D.C.), 2013-10, Vol.76 (10), p.1881-1888
• Main Authors: Lee, Ik-Soo, Yu, Song Yi, Jung, Seung-Hyun, Lee, Yu-Ri, Lee, Yun Mi, Kim, Joo-Hwan, Sun, Hang, Kim, Jin Sook
• Format: Article
• Language: English
• Subjects: Animals; Catechin - chemistry; Danio rerio; Drugs, Chinese Herbal - chemistry; Drugs, Chinese Herbal - isolation & purification; Drugs, Chinese Herbal - pharmacology; Flavonoids - chemistry; Freshwater; Glycosides - chemistry; Glycosides - isolation & purification; Glycosides - pharmacology; Inhibitory Concentration 50; Larva - drug effects; Molecular Structure; Phenols - chemistry; Proanthocyanidins - chemistry; Proanthocyanidins - isolation & purification; Proanthocyanidins - pharmacology; Retinal Vessels - drug effects; Rosaceae - chemistry; Stereoisomerism; Zebrafish - physiology
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np400442b

Three new A-type proanthocyanidins (1–3), ent-epiafzelechin-(2α→O→7,4α→8)-ent-afzelechin 3′-O-β-d-glycopyranoside (1), ent-epiafzelechin-(2α→O→7,4α→8)-ent-epiafzelechin-(2α→O→7,4α→8)-ent-afzelechin (2), and ent-epiafzelechin-(2α→O→7,4α→8)-ent-epicatechin-(2α→O→7,4α→8)-ent-afzelechin (3), and three known compounds (4–6) were isolated from the whole plant of Spenceria ramalana. The structures of the new proanthocyanidins were established by spectroscopic and chemical studies. The inhibitory effects of compounds 1–6 on the formation of advanced glycation end products were examined in vitro. Compounds 3 and 6 showed the strongest inhibition, with IC50 values of 17.4 ± 0.5 and 14.1 ± 1.6 μM, respectively. The effects of these isolates on the dilation of hyaloid-retinal vessels induced by high glucose (HG) in larval zebrafish were also investigated. Compound 3 reduced the dilation of HG-induced hyaloid-retinal vessels most effectively. This compound reduced the diameters of HG-induced hyaloid-retinal vessels by about 157.7% and 164.1% at 10 and 20 μM, respectively, versus the HG-treated control group.