Guaiane Sesquiterpenes from the Rhizome of Curcuma xanthorrhiza and Their Inhibitory Effects on UVB-induced MMP-1 Expression in Human Keratinocytes

Abstract

A new guaiane sesquiterpene, (1R,4S,5S,10R)-10-methyl guaianediol (1), along with five known compounds, 10-methylalismoxide (2), (+)-alismoxide (3), isozedoarondiol (4), zedoarondiol (5), and zedoalactone B (6), were isolated from the rhizomes of Curcuma xanthorrhiza Roxb. Compounds 1-6 were isolated from this plant for the first time. Chemical structures were determined using nuclear magnetic resonance (NMR), electron ionization mass spectrometry (EI/MS), polarimetry, circular dichroism (CD), and infrared spectroscopy (IR). Compounds 3 and 4 decreased MMP-1 expression in UVB-treated human keratinocytes by about 8.9-fold and 7.6-fold at the mRNA level, and by about 9.2-fold and 6.6-fold at the protein level, respectively. Results indicate that the isolated compounds have anti-aging effects by inhibiting MMP-1 expression in skin cells.

Research Progress on Sesquiterpenoids of Curcumae Rhizoma and Their Pharmacological Effects

“…Currently, 54 germacrane sesquiterpenoids have been isolated from Curcumae Rhizoma (Figure 2, Table 2). These natural products frequently engage in the formation of a five-membered ring at C-8 and C-12, yielding diverse structural moieties, such as furan rings (139)(140)(141)(142)(143)(144)(145), lactone rings (146)(147)(148)(149)(150)(151)(152)(153)(154)(155)(156)(157)(158), and lactam rings (161-168). This type of compound is prone to oxidation, which can produce aldehydes, ketones, esters, or oxygen bridges.…”

“…Germacrane-type sesquiterpenoids containing a lactone ring are frequently substituted with hydroxyl groups at C-8 (147, 149-151, 154-156). Sesquiterpenoids are also prone to forming oxygen bridges, with tricyclic oxygen rings appearing frequently at C-1/C-10 (129-135), C-4/C-5 (126,128,(143)(144)(145), or C-1/C-5 (136). It is noteworthy that multiple pairs of germacrane-type enantiomers (152/153, 155/156, 163/164, 165/166) have been isolated from Curcumae Rhizoma.…”

“…These compounds actively diminish free radical concentrations within the organism, alleviate oxidative harm, and consequently hold promise in the prevention and treatment of associated diseases [80]. In the context of skin regeneration, it has been discovered that alismoxide (3), isozedoarondiol (20), isoprocurcumenol (43), germacrone (116), and 13-hydroxygermacrone (124) can activate the epidermal growth factor receptor, thereby promoting skin regeneration [142][143][144]. In relation to other activities, procurcumenol (29), germacrone (116), and dehydrocurdione (121) also exhibit neuroprotective effects [143]; curcumanolide A (241) has a relaxant effect on uterine smooth muscle tissue [15]; curdione (117) attenuates sepsis-induced lung injury [145]; curcumenol (61) reduces disc inflammation and improves disc catabolism [146]; zederone (143) has the potential to be a drug for the treatment of dementia [147]; and curcumenone (258) can exert a protective effect against intoxication [148].…”