Chemical Composition and Antimicrobial Activities of the Essential Oils from the Rhizomes of Four Hedychium Species from South India

Journal of Essential Oil Research: JEOR, Jan/Feb 2007 by Sabulal, Baby, George, Varughese, Dan, Mathew, Pradeep, Nediyaparambu Sukumaran

Abstract

The chemical composition of the essential oils from the rhizomes of four South Indian Hedychium species, viz. H. venustum Wight, H. spicatum Ham. ex Smith var. acuminatum (Roscoe) Wall., H. coronarium Koenig and H. flavescens Carey ex Roscoe was investigated by GC and GC/MS. 1,8-Cineole was the most abundant constituent in the first three oils, present at concentrations of 45.4%, 44.3% and 48.7%, respectively. β-Pinene (43.6%) was the major constituent in the oil from H. flavescens. The percentages of sesquiterpenes were the highest in the rhizome oil of H. venustum (24.0%) followed by H. spicatum var. acuminatum (22.2%), H. flavescens (0.6%) and H. coronarium (0.5%). The antimicrobial activities of all four rhizome oils were tested by the disc diffusion method against three Gram-positive and seven Gram-negative bacteria and two fungi. The strongest activities were observed for the rhizome oil from H. flavescens, especially against Salmonella typhi (23 mm inhibition zone), Escherichia coli (18 mm), Proteus vulgaris (15 mm) and the fungi Candida albicans (13 mm) and C. glabrata (14 mm).

Key Word Index

Hedychium venustum, Hedychium spicatum var. acuminatum, Hedychium coronarium, Hedychium flavescens, Zingiberaceae, essential oil composition, 1,8-cineole, β-pinene, antimicrobial activity.

Introduction

Hedychium belonging to the family Zingiberaceae is commonly known as ginger lilies and is a genus of herbs with thick, fleshy and branched rhizomes. In South Asia, the genus Hedychium has over 80 species. Recent studies reported 41 species and four varieties in India, of which 17 species are endemic to India (1,2). Hedychium spicatum is used as a bactericide and fungicide and for the treatment of pain, stomach ailments and inflammation in Indian traditional medicine (3,4). Hedychium coronarium is used for the treatment of swelling, sore throat, tonsillitis and tumor (3). Hedychium spicatum rhizomes are used in perfumery in Tropical Asia. Hedychium spp. are widely cultivated for ornamental purposes especially for their sweet scented flowers (5).

The chemical composition of the rhizome oils from H. spicatum var. acuminatum (Nainital, India), H. aurantiacum (Nainital, India), H. coronarium (Tahiti Island, French Polynesia), H. acuminatum (Darjeeling, India), H. gardenarium (Darjeeling, India) and H. cylindricum (Sabah, Malaysia) were previously studied (4,6-14). Monoterpenes constituted major portions of these rhizome oils, with 1,8-cineole as the single major constituent in H. spicatum var. acuminatum, H. coronarium and H. acuminatum; β-pinene in H. gardenarium; linalool in H. aurantiacum and terpinen-4-ol in H. cylindricum (4, 6-14). Flower oils of H. coronarium (Chiba, Japan and China) and H. flavum (China); leaf and flower oils of H. coronarium (Madagascar) and H. gardenarium (San Miguel Island, Azores) and oil from the aerial parts ofH.flavum (Madagascar) were also investigated (15-21). The leaf and flower oils of H. gardenarium from San Miguel Island, Azores were subjected to antimicrobial studies (20).

Genus Hedychium is poorly represented in South India with only four species: H. venustum Wight, H. spicatum Ham. ex Smith van acuminatum (Roscoe) Wall., H. coronanum Koenig and H.flavescens Carey ex Roscoe (1,2). In this article, we report the chemical characterization, antibacterial and antifungal activities of the oils from the rhizomes of these bur Hedychium species. This is the first report on the oils from H. flavescens and endemic H. venustum. Essential oils from the rhizomes of H. coronarium (8-11) and H. spicatum var. acuminatum (4,6,9) have been previously studied, but this is the first report on the South Indian accessions of these two species.

Experimental

Plant materials: All four Hedychium specimens were collected from their natural habitats in the Kerala region of Western Chats in India, by random sampling from plants in a single established population. Rhizomes of H. spicatum var. acuminatum were collected from the Ponmudi Hill Station, c. 1100 m, in Thiruvananthapuram district in September 2004. Rhizomes of H. venustum and H. flavescens were collected respectively from Devikulam, c. 1800 m, and Mattupetty, c. 1700 m, in Munnar, Idukki district in September 2004. Rhizomes of H. coronarium were collected from the garden, at c. 110 m, of Tropical Botanic Garden and Research Institute, Palode in Thiruvananthapuram district in September 2004. Voucher specimens were kept at the Herbarium of Tropical Botanic Garden and Research Institute (TBGT) and the voucher numbers were 54609,54620,54622 and 54624 for H. spicatum var. acuminatum, H. flavescens, H. venustum and H. coronarium, respectively.

Oil isolation: Fresh rhizomes of H. venustum (1228 g), H. spicatum var. acuminatum (955 g), H. coronarium (640 g) and H.flavescens (1027 g) were hydrodistilled in a Clevenger-type apparatus for 3 h to obtain the corresponding rhizome oils. The oil yields and percentages based on fresh weights of rhizomes were H. venustum 2 mL (0.16%), H. spicatum var. acuminatum 1.25 mL(0.13%), H. ctironarium 0.8 mL(0.13%) and H. flavescens 0.5 mL (0.05%). All oils were pleasant smelling, transparent with a faint yellow color except that of H. flavescens, which was colorless.