Indole Glycosides from <i>Calanthe discolor</i> with Proliferative Activity on Human Hair Follicle Dermal Papilla Cells

Abstract

A methanol extract from the underground part of Calanthe discolor Lindl. (Orchidaceae) demonstrated significant proliferative activity on human hair follicle dermal papilla cells (HFDPC, % of control: 120.8 0.2%) at 100 µg/mL against HFDPC. Through bioassay-guided separation of the extract, a new indole glycoside named 6′-O-β-D-apiofuranosylindican (1) was isolated along with six known compounds (2-7) including three indole glycosides. The stereostructure of 1 was elucidated based on its spectroscopic properties and chemical characteristics. Among the isolates, 1 (110.0 1.0%), glucoindican (3, 123.9 6.8%), and calanthoside (4, 158.6 7.1%) showed significant proliferative activity at 100 µM. Furthermore, the active indole glycosides (1, 3, and 4) upregulated the expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor-7 (FGF-7) mRNA and protein in HFDPC, which could be the mechanism of their proliferative activity.

Total Synthesis of Calanthoside, a Potential Hair Growth Stimulant: A Facile Synthetic Approach via One-Pot S- and O-Glucosidic Bond Formation

“…Tetramethylsilane (TMS) was used as an internal standard for 1 H NMR measurements in CDCl 3 , whereas 13 C NMR measurements utilized the solvent signal (77.0 ppm) of CDCl 3 for this purpose. When CD 3 OD and DMSO-d 6 were used for the measurement of 1 H and 13 6.59 (1H, br d-like, J = 7.9, H-3), 6.60 (1H, br t-like, J = 7.9, H-5), 7.36 (1H, dt, J = 7.9, 1.7, H-4), 7.80 (1H, dd, J = 7.9, 1.7, H-6), 8.11 (1H, s, NH), 12.7 (2H, br s, CO 2 H); 13 C NMR (150 MHz, DMSO-d 6 ) δ 41.9 (NHCH 2 CO 2 H), 110.5 (C-1), 111.5 (C-3), 114.8 (C-5), 131.7 (C-6), 134.4 (C-4) N (36.7 mL, 256 mmol) was heated at 100 °C for 2 h. After being cooled, the reaction mixture was poured into cold water (600 mL) and neutralized with NaHCO 3 . The resulting suspension was extracted with EtOAc (200 mL × 3), washed with brine (200 mL), and concentrated in vacuo to give a deep brown solid (11.5 g), which on recrystallization from a mixture of n-hexane and EtOAc gave 1-acetylindoxyl acetate (13, 10a,c,11 A mixture of 13 (10.0 g, 46.0 mmol), Na 2 SO 3 (14.5 g, 115 mmol), and H 2 O (150 mL) was heated at 90 °C for 3 h. The reaction mixture was extracted with EtOAc (200 mL × 3).…”

“…liukiuensis SCHLTR . The proliferative activity of 1 toward human hair follicle dermal papilla cells (HFDPCs) is known to be equal to or greater than that of minoxidil, thus suggesting that 1 might be a potential lead compound for treating AGA. Besides, 1 has a unique S , O -bisdesmoside structure, in which two d -glucose units are connected to the 2-sulfanyl-3-hydroxyindole core through S - and O -glucoside linkages.…”