Ginseng is a traditional medicinal herb commonly consumed world-wide owing to its unique family of saponins called ginsenosides. The absorption and bioavailability of ginsenosides mainly depend on an individual’s gastrointestinal bioconversion abilities. There is a need to improve ginseng processing to predictably increase the pharmacologically active of ginsenosides. Various types of ginseng, such as fresh, white, steamed, acid-processed, and fermented ginsengs, are available. The various ginseng processing methods produce a range ginsenoside compositions with diverse pharmacological properties. This review is intended to summarize the properties of the ginsenosides found in different Panax species as well as the different processing methods. The sugar moiety attached to the C–3, C–6, or C–20 deglycosylated to produce minor ginsenosides, such as Rb1, Rb2, Rc, Rd→Rg3, F2, Rh2; Re, Rf→Rg1, Rg2, F1, Rh1. The malonyl-Rb1, Rb2, Rc, and Rd were demalonylated into ginsenoside Rb1, Rb2, Rc, and Rd by dehydration. Dehydration also produces minor ginsenosides such as Rg3→Rk1, Rg5, Rz1; Rh2→Rk2, Rh3; Rh1→Rh4, Rk3; Rg2→Rg6, F4; Rs3→Rs4, Rs5; Rf→Rg9, Rg10. Acetylation of several ginsenosides may generate acetylated ginsenosides Rg5, Rk1, Rh4, Rk3, Rs4, Rs5, Rs6, and Rs7. Acid processing methods produces Rh1→Rk3, Rh4; Rh2→Rk1, Rg5; Rg3→Rk2, Rh3; Re, Rf, Rg2→F1, Rh1, Rf2, Rf3, Rg6, F4, Rg9. Alkaline produces Rh16, Rh3, Rh1, F4, Rk1, ginsenoslaloside-I, 20(S)-ginsenoside-Rh1-60-acetate, 20(R)-ginsenoside Rh19, zingibroside-R1 through hydrolysis, hydration addition reactions, and dehydration. Moreover, biological processing of ginseng generates the minor ginsenosides of Rg3, F2, Rh2, CK, Rh1, Mc, compound O, compound Y through hydrolysis reactions, and synthetic ginsenosides Rd12 and Ia are produced through glycosylation. This review with respect to the properties of particular ginsenosides could serve to increase the utilization of ginseng in agricultural products, food, dietary supplements, health supplements, and medicines, and may also spur future development of novel highly functional ginseng products through a combination of various processing methods.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Eggplant (Solanum melongena L.) is an excellent source of vitamins A and C and of flavonoid compounds, which are important antioxidant components believed to reduce the risk of various diseases. We investigated the antioxidant activity and flavonoid content in eggplant leaves and fruits to identify genetic resources with high antioxidant capacity for use in food or as feed additives, and also determined the influence of days to flowering, leaf blade colors, and latitudes of origin on the antioxidant activity and flavonoid content in eggplant leaves. The accessions originating from 45°N showed the highest flavonoid contents (AVG. = 15.4 μg mg -1 ) followed by accessions from 30°～45°N (AVG. = 13.0 μg mg -1 ), 15°～30°N (AVG. = 11.0 μg mg -1 ), and 0°～15°N (AVG. = 9.5 μg mg -1 ). The same pattern was also found in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) antioxidant activities. High ABTS and DPPH activity and flavonoid content were found in the early-flowering accessions. All flavonoids of the greenish violet leaves were significantly higher than those of green leaves. The flavonoid concentration in eggplant leaves was 10 to 20 fold greater, at an average of 15.6 μg mg -1 , than that of the fruit (AVG. = 0.9 μg mg -1 ).Taken together, eggplant leaves represent a potential source of natural antioxidants due to their high flavonoid content.