Chemical profiles of volatiles in fourAlpiniaspecies from Kerala, South India

An overview of the chemical composition and biological activities of essential oils from Alpinia genus (Zingiberaceae)

Alpinia Roxb. is the largest genus of the Zingiberaceae family. A large number of Alpinia species has been used as food and traditional medicines. Alpinia essential oils have been studied for their chemical profiles, in which 1,8-cineole, β-pinene, α-pinene, β-myrcene, camphor, γ-terpinene, p-cymene, geraniol, α-fenchyl acetate, ocimene, methyl cinnamate, and β-caryophyllene have been found to be the major compounds. Essential oils isolated from Alpinia plants have been reported to have antimicrobial, cytotoxic, antioxidant, anti-inflammatory, anti-asthmatic, tyrosinase inhibitory, insecticidal, and larvicidal activities and slimming aromatherapy. In this review, the comprehensive information regarding the volatile components of various Alpinia plants, the bioactivities of Alpinia essential oils and their major compounds are provided.

In Vivo and In Vitro Toxicity Profiles of Hexane Extract of Alpinia malaccensis Rhizome in Rat and Cell Line Models

The objective of the study was to evaluate the potential toxicity of crude n-hexane extract of Alpinia malaccensis rhizome. The in vivo acute oral toxicity was evaluated by administering a single oral dose of the extract at 0, 300, or 2000 mg/kg body weight to female Wistar rats according to modified OECD Test Guideline 423. For the in vitro cytotoxicity study, A549, HepG2, 3T3, and COS-7 cell lines were exposed to different doses of A. malaccensis extract and cell viability was assessed adopting MTT assay followed by AO/EB staining, Hoechst staining, and comet assay with a view to compare the cellular and molecular mechanisms underlying the toxicity, if any. It was found that administration of 2000 mg/kg bw dose in in vivo oral acute toxicity study did not produce significant toxicity or mortality. No significant (p < 0.05) differences were observed for body weight and hematological and biochemical parameters compared to control after 14 days of treatment. No changes in behavior, body weight, hematological and biochemical parameters, and aspects of histopathology were observed when compared to the control. Thus, the possible oral lethal dose for A. malaccensis extract is above 2000 mg/kg body weight. The in vitro cytotoxicity analysis showed nontoxicity concentrations of the extract to be 2, 1.4, 30, and 1.4 µg/mL for A549, HepG2, 3T3, and COS-7 cells, respectively, where no apoptotic/necrotic cell death and DNA damage were observed. In conclusion, the extract of rhizome of A. malaccensis did not produce apparent cytotoxicity or acute oral toxicity, confirming the scope to use A. malaccensis as a safe food preservative and a natural therapeutic product after further subacute and chronic toxicity studies.

Thermal desorption modulation based detection of volatile constituents of Alpinia galanga by two dimensional gas chromatography and time of flight mass spectrometry

Alpinia galanga Wild.(L.) is well known for its aromatic constituents. Though the aromatic composition is already known, but lots of constituents which contributing overall aroma of the oil are still unknown due to the co-eluting factor of single column in GC-MS. Thus the current study aims to characterise maximum volatile constituents present in the essential oil of A. galanga using thermal desorption modulator of two-dimensional gas chromatography and time-of-flight mass spectrometry. The 102 compounds with good match and high probability value were identified out of which 42 were identified for the first time. The total identified compounds include 47 hydrocarbons 25 alcohols, 7 ketones, 7 esters, 3 aldehyde, 4 ethers and 9 other classified aromatic compounds. It was further categorised into Monoterpene Hydrocarbons, Oxygenated Monoterpenes, Sesquiterpene Hydrocarbons and Oxygenated Sesquiterpenes. The major constituent also varies with respect to area percentage. The in-depth characterisation will help in its qualitative analysis.

Antimicrobial activity and phytochemical screening of Alpinia malaccensis (Ran-kiriya) against food-borne bacteria

AIMS

Investigation of antimicrobial activity and phytochemicals of Alpinia malaccensis (Ran-kiriya) against foodborne bacteria Staphyloccocus aureus, Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium.

METHODS AND RESULTS

Antibacterial activity was tested on the above four foodborne bacteria using agar disc diffusion and broth dilution assay. Alpinia malaccensis rhizome extract chemical composition was determined using gas chromatography-mass spectrometry (GCMS). Active compound was identified using thin-layer chromatography (TLC) and confirmed by nuclear magnetic resonance spectroscopy (NMR). The A. malaccensis rhizome hexane crude extract showed significantly (P < 0·05) higher diameter of inhibition (DIZ) 40 ± 0·52, 38 ± 0·96 and 36 ± 1·45 mm for S. aureusSA113, MSSASS25D and methicillin-resistant S. aureus compared with other tested bacteria. The minimum inhibition concentration and minimum bactericidal concentration were 0·625 and 5 mg ml^-1 for S. aureus 113. TLC showed DIZ 39 ± 0·12 mm only for one fraction. The crude extract showed 82·87% a major compound by GCMS which is the active fraction. This purified active fraction was confirmed as 1'acetoxychavicol acetate (1'ACA) by NMR. No significantly different inhibition was observed for crude extract and purified compound.

CONCLUSIONS

Bioactive 1'ACA of A. malaccensis showed strong antibacterial activity against S. aureus strains including MRSA strain.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first to identify 1'ACA from A. malaccensis. The crude or purified compound could potentially be developed as antimicrobials.

Development and validation of HPTLC fingerprints of three species of Alpinia with biomarker Galangin

BACKGROUND

Alpinia galanga (L.) Willd. commonly called as Rasna, Greater galangal or Kulinjan is a medicinally important rhizome used in Indian traditional system of medicine to cure a number of ailments. A. galanga is the main source of a galangin -a medicinally important flavanol which has a number of pharmacological properties viz. anti-mutagenic, and anti-inflammatory. Due to the high demand for the rhizome of A. galanga traders are now substituting it with rhizomes of A. calcarata and A. officinarum.

METHODS

The present study aims to develop high performance thin layer chromatographic (HPTLC) fingerprinting of A. galanga with its adulterants or substitutes and to quantify bioactive galangin present thereof. Methanolic extracts were obtained from rhizomes of the three species of Alpinia used for HPTLC analysis using silica gel 60 F254 plates and hexane: ethyl acetate: acetic acid (6.2: 2.8: 1.0 v/v/v); the densitometric analysis was performed at 272 nm.

RESULTS

By comparison of Rf values and of the spectra of the bands with those of the standard galangin was identified in all three samples. HPTLC quantitative analysis of the methanolic extracts showed the decline trend in the quantity of the galangin in the three species of Alpinia as A. galanga (7.67 ± 0.36 mg/g) > A. officinarum (5.77 ± 0.71 mg/g) > A. calcarata (4.31 ± 0.44 mg/g). The HPTLC method was validated using International Conference on Harmonization (ICH) guidelines. The HPTLC method showed good linearity, recovery and high precision of biomarker.

CONCLUSIONS

Rapid and reproducible method is useful for routine analysis of galangin and quality control of Alpinia galangal along with its adulterants or substitutes.

Identification of Ginger (Zingiber officinale Roscoe) Volatiles and Localization of Aroma-Active Constituents by GC-Olfactometry

For the characterization of chemical components contributing to the aroma of ginger, which could benefit the development of deep-processed ginger products, volatile extracts were isolated by a combination of direct solvent extraction-solvent-assisted flavor evaporation and static headspace analysis. Aroma-impact components were identified by gas chromatography-olfactometry-mass spectrometry, and the most potent odorants were further screened by aroma extract dilution analysis (AEDA) and static headspace dilution analysis (SHDA). The AEDA results revealed that geranial, eucalyptol, β-linalool, and bornyl acetate were the most potent odorants, exhibiting the highest flavor dilution factor (FD factor) of 2187. SHDA indicated that the predominant headspace odorants were α-pinene and eucalyptol. In addition, odorants exhibiting a high FD factor in SHDA were estimated to be potent aroma contributors in AEDA. The predominant odorants were found to be monoterpenes and sesquiterpenes, as along with their oxygenated derivatives, providing minty, lemon-like, herbal, and woody aromas. On the other hand, three highly volatile compounds detected by SHDA were not detected by AEDA, whereas 34 high-polarity, low-volatility compounds were identified only by AEDA, demonstrating the complementary natures of SHDA and AEDA and the necessity of utilizing both techniques to accurately characterize the aroma of ginger.

Chemical Constituents of Essential Oils from the Leaves, Stems, Roots and Fruits of Alpinia polyantha

The essential oils obtained from the leaves, stems, roots and fruits of Alpinia polyantha D. Fang (Zingiberaceae) have been studied. The leaf oil was comprised mainly of camphor (16.1%), α-pinene (15.2%) and β-agarofuran (12.9%), while the major constituents of the stem oil were α-pinene (12.4%), β-cubebene (10.6%), β-agarofuran (10.3%) and globulol (8.8%). However, β-cubebene (12.6%), fenchyl acetate (10.8%), β-maaliene (9.0%), aristolone (8.8%) and α -pinene (8.2%) were the compounds occurring in higher amounts in the root oil. The quantitatively significant compounds of the fruit oil were δ-cadinene (10.9%), β-caryophyllene (9.1%), β-pinene (8.7%) and α-muurolene (7.7%).