Two new diterpenoids from the rhizomes of Zingiber officinale

Dimeric diarylheptanoids with anti-inflammatory activity from Zingiber officinale

Two previously undescribed chain diarylheptanoid derivatives (2-3), five previously undescribed dimeric diarylheptanoids (4-8), together with one known cyclic diarylheptanoid (1) were isolated from Zingiber officinale. Their structures were elucidated by extensive spectroscopic analyses (HR-ESI-MS, IR, UV, 1D and 2D NMR) and ECD calculations. Biological evaluation of compounds 1-8 revealed that compounds 2, 3 and 4 could inhibit nitrite oxide and IL-6 production in lipopolysaccharide induced RAW264.7 cells in a dose-dependent manner.

Effect of drying and processing on diterpenes and other chemical constituents of ginger

Ginger (Zingiber officinale Roscoe) is a perennial plant widely distributed in tropical and subtropical regions, and its rhizomes are sometimes processed for use in traditional medicine. In Japan, "ginger" (Shokyo in Japanese) and "processed ginger" (Kankyo in Japanese) are defined as crude drugs derived from ginger rhizomes, which have different medicinal properties due to complex changes in their chemical composition during processing. The effects of processing on gingerols and shogaols are well known, but for other phytochemicals remain unclear. Therefore, the present study prepared dried ginger and processed ginger derived from three ginger cultivars (Kintoki, Kogane, and Tosa ginger) and examined the effects of drying and processing on multiple secondary metabolites. Drying showed only a limited effect on ginger chemical constituents and significantly reduced [6]-gingerol content in Tosa ginger. In contrast, processing altered content of numerous metabolites, such as terpenes and gingerol-related compounds, in addition to those gingerols and shogaols. Notably, processing reduced labdane diterpene content, including labdadienedial, aframodial, and galanolactone in all ginger cultivars. Our results show galanolactone with anti-emetic activity was abundant in dried ginger and decreased following processing, highlighting different uses between "ginger" and "processed ginger" in traditional medicine. Overall, we comprehensively clarified the impact of drying and processing on terpenes and gingerol-related compounds. These findings help reveal the varying medicinal properties among crude drugs prepared from Z. officinale.