Hedychium

Abstract: A phytochemical study of the rhizome essential oils of four different Hedychium species was performed by means of GC and GC/MS analyses. H. ellipticum mainly contained 1,8-cineole, sabinene, and terpin-4-ol, while H. aurantiacum possessed terpin-4-ol, para-cymene, and bornyl acetate as the major entities. Similarly, trans-meta-mentha-2,8-diene and linalool were noticed in H. coronarium. Three different collections (I-III) of H. spicatum showed amazing differences in the relative contents of their essential oils, 1,8-cineole and 10-epi-gamma-eudesmol being identified as markers for samples I and II, terpin-4-ol and sabinene being the major compounds in sample III. The rhizome essential oils of the above species were studied for their antioxidant activities by different methods, including their effect on the chelating properties of Fe(2+), DPPH radical-scavenging activity, and reducing power. Antimicrobial screenings of the oils by the paper-disc method were performed against Staphylococcus aureus, Shigella flexneri, Pasteurella multocida, Escherichia coli, and Salmonella enterica enterica, and the respective minimum-inhibitory-concentration (MIC) values were determined. The rhizome essential oils from all Hedychium species exhibited moderate-to-good Fe(2+) chelating activity. H. spicatum from collection site III showed a completely different DPPH radical-scavenging profile than the samples from the other collection sites.

Abstract: The nutritional compositions and phytochemical properties of 8 edible flowers of the Ginger family (Zingiberaceae) commonly found in Thailand are reported herein. The plant genera investigated were Zingiber (Ginger, Phlai Dam, Krathue), Hedychium (2 morphological filament forms), Curcuma (Ao), Etlingera (Torch ginger), Amomum (Chi Kuk) and Alpinia (Galangal), which are eaten fresh or cooked as ingredients in the preparation of many Thai dishes. The proximate compositions (moisture, ash, fibre, protein, fat and carbohydrate contents) varied among the different genera. The plants sampled were generally low in fat content (< 1%), which contributed as little as 30% of the total caloric energy. Edible plant parts contained substantially high amounts of potassium (max. 737.21 mg/100g), calcium (max. 140.15 mg/100g), and iron (~0.32 mg/100g). Among the tested samples, torch ginger had the highest vitamin C content (1.05 mg/100g), total phenolic and total flavonoid contents and as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) acvitivity. On the other hand, the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay suggested that Hedychium species possessed the highest antioxidant activity (~5.38 mg TEAC/g extract). Our results prove that edible plants of the Zingiberaceae family found in Thailand are rich sources of potentially important nutrients.

Abstract: The antimicrobial properties of essential oils have been documented, and their use as "biocides" is gaining popularity. The aims of this study were to analyze the chemical composition and assess the biological activities of Hedychium essential oils. Oils from 19 Hedychium species and cultivars were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The antifungal and insecticidal activities of these oils were tested against Colletotrichum acutatum, C. fragariae, and C. gloeosporioides, and three insects, the azalea lace bug (Stephanitis pyrioides), the yellow fever mosquito (Aedes aegypti), and the red imported fire ant (Solenopsis invicta). Hedychium oils were rich in monoterpenes and sesquiterpenes, especially 1,8-cineole (0.1%-42%), linalool (<0.1%-56%), a-pinene (3%-17%), b-pinene (4%-31%), and (E)-nerolidol (0.1%-20%). Hedychium oils had no antifungal effect on C. gloeosporioides, C. fragariae, and C. acutatum, but most Hedychium oils effectively killed azalea lace bugs. The oils also show promise as an adult mosquito repellent, but they would make rather poor larvicides or adulticides for mosquito control. Hedychium oils acted either as a fire ant repellent or attractant, depending on plant genotype and oil concentration.