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Background: Zingiber nimmonii (J. Graham) Dalzell (syn. Z. cernuum) endemic to peninsular India have been documented to be in use since ancient times in several traditional systems of medicine. Z. nimmonii with ethnomedicinal applications constitute a rich source of secondary metabolites toward identifying potential bioactive constituents with antioxidant and antimicrobial properties. Objective: Rhizomes of Z. nimmonii (J. Graham) Dalzell, endemic to the Western Ghats, were analyzed for bioactivity and phytochemical composition. Materials and Methods: Polyphenolic contents, namely total phenolics (TPs), total flavonoids (TFs) and total tannin (TT), were determined and expressed using gallic acid (GA), catechin (C) and tannic acid (TA) as standards. Antibacterial and antifungal activities were evaluated against two Gram-positive, three Gram-negative bacteria and three fungi by agar well diffusion method. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assay, and volatile metabolite composition was determined by gas chromatography–mass spectrometry (GC-MS) analysis. Results: THE highest TF and TT contents were detected in ethyl acetate (557.64 ± 41.74 mg CE. 100 g-1 DW) and isopropanol (63.995 ± 2.062 mg TA equivalent. 100 g-1 DW) extract, respectively. High TP content in isopropanol extract (112.80 ± 10.99 mg GA equivalent. 100 g-1 DW) contributed to antimicrobial activity against Gram-positive Staphylococcus aureus (16.3 ± 0.6 mm) and antifungal activity against Aspergillus flavus (11.7 ± 0.6 mm). Methanol extracts showed high antioxidant activity as determined by DPPH (67.4 ± 12.5 μg/ml) and FRAP (127.8 ± 12.4 μg/ml) assays. Major bioactive phytochemical constituents in Z. nimmonii rhizome following GC-MS analysis included heptanediamide, N, N'-di-benzoyloxy (arachidonic acid inhibitor), n-hexadecanoic acid (antibacterial, cytotoxic, and antioxidant), and oleic acid (antitumor). Conclusion: The present study demonstrates potential of Z. nimmonii rhizomes as a rich source of secondary metabolites which can be exploited toward developing anti-infective formulations and free radical quenchers. [ABSTRACT FROM AUTHOR]

Eleven fungal endophytes were isolated from the plant parts of Z. nimmonii (J. Graham) Dalzell, an endemic species of the Western Ghats, India, a biodiversity hotspot area. The endophytic isolates were characterized by the sequencing of the Internal Transcribed Spacer (ITS) regions and designated as strains by depositing ITS sequences in the Gen Bank sequence database. All the strains were cultured in Potato Dextrose broth (PDB, 500 mL) contained in Erlenmeyer flasks to obtain the secondary metabolites. The culture filtrate was extracted with ethyl-acetate (EA) three times and concentrated by flash evaporation to obtain EA crude dry extract. The strains were evaluated for the antibacterial potentials against six pathogenic bacterial strains viz., Bacillus subtilis (MTCC 121), Staphylococcus aureus (MTCC 7443) Pseudomonas aeruginosa (MTCC 7093), Escherichia coli (MTCC 729), Enterobacter aerogenes (MTCC 111) and Klebsiella pneumoniae (MTCC 661). Nine endophytic fungal extracts except Alternaria consortiale and Hypocrea lixi showed inhibitory activities against at least two of the six test bacterial strains. Bipolaris specifera (KM114290) exhibited the highest inhibition zones ranging from 15.1 ± 0.3 to 26.7 ± 1.1 mm (diameter), against all six test bacteria in the agar disk diffusion assay, and with Minimum Inhibitory Concentrations (MIC's) of 0.04–0.14 mg/mL, followed by Aspergillus terreus. B. specifera extract was therefore selected and characterized for the identification of antibacterial compounds by chromatographic techniques. Seven antibacterial compounds viz., (1) Bicyclo[3.2.0]heptan-2-one, 6-hydroxy-5-methyl-6-vinyl; (2) Adipic acid divinyl ester; (3) 1,4-Naphthoquinone, 6-acetyl-2,5-dihydroxy; (4) Decanedioic acid, 3,7-dimethyl ester; (5) (Z)-4-Hexenoic acid 2-acetyl-2-methyl-ethyl ester and (6) Butanoic acid 2-acetyl-3-methyl-methyl ester and (7) Caffeic acid, were identified through liquid and gas chromatography. These compounds are mainly volatile esters of fatty acids, phenolics and adipic acid found rare in nature. This study envisages the possible drug discovery using endophytes from traditional and endemic medicinal species. [ABSTRACT FROM AUTHOR]

Eleven fungal endophytes were isolated from the plant parts of Z. nimmonii (J. Graham) Dalzell, an endemic species of the Western Ghats, India, a biodiversity hotspot area. The endophytic isolates were characterized by the sequencing of the Internal Transcribed Spacer (ITS) regions and designated as strains by depositing ITS sequences in the Gen Bank sequence database. All the strains were cultured in Potato Dextrose broth (PDB, 500 mL) contained in Erlenmeyer flasks to obtain the secondary metabolites. The culture filtrate was extracted with ethyl-acetate (EA) three times and concentrated by flash evaporation to obtain EA crude dry extract. The strains were evaluated for the antibacterial potentials against six pathogenic bacterial strains viz., Bacillus subtilis (MTCC 121), Staphylococcus aureus (MTCC 7443) Pseudomonas aeruginosa (MTCC 7093), Escherichia coli (MTCC 729), Enterobacter aerogenes (MTCC 111) and Klebsiella pneumoniae (MTCC 661). Nine endophytic fungal extracts except Alternaria consortiale and Hypocrea lixi showed inhibitory activities against at least two of the six test bacterial strains. Bipolaris specifera (KM114290) exhibited the highest inhibition zones ranging from 15.1 ± 0.3 to 26.7 ± 1.1 mm (diameter), against all six test bacteria in the agar disk diffusion assay, and with Minimum Inhibitory Concentrations (MIC's) of 0.04–0.14 mg/mL, followed by Aspergillus terreus. B. specifera extract was therefore selected and characterized for the identification of antibacterial compounds by chromatographic techniques. Seven antibacterial compounds viz., (1) Bicyclo[3.2.0]heptan-2-one, 6-hydroxy-5-methyl-6-vinyl; (2) Adipic acid divinyl ester; (3) 1,4-Naphthoquinone, 6-acetyl-2,5-dihydroxy; (4) Decanedioic acid, 3,7-dimethyl ester; (5) (Z)-4-Hexenoic acid 2-acetyl-2-methyl-ethyl ester and (6) Butanoic acid 2-acetyl-3-methyl-methyl ester and (7) Caffeic acid, were identified through liquid and gas chromatography. These compounds are mainly volatile esters of fatty acids, phenolics and adipic acid found rare in nature. This study envisages the possible drug discovery using endophytes from traditional and endemic medicinal species. [ABSTRACT FROM AUTHOR]

Intraspecific genetic variation was assessed in cultivated ginger (Zingiber officinale) and its three wild congeners: Z. neesanum, Z. nimmonii and Z. zerumbet from Western Ghats, South India using 169 amplified fragment length polymorphism (AFLP) markers generated by six primer combinations. Different genetic diversity estimates depicted a striking difference in the genetic diversity of the species studied. The very low level of genetic diversity recorded in ginger complies with its obligatory asexual breeding behaviour. Contrary to the expectations, the genetic diversity of the widely distributed Z. zerumbet was relatively low while that of the endemic species Z. neesanum and Z. nimmonii was higher. Mode of reproduction presumably governs the level of genetic diversity in Zingiber species. Further, the analyses of AFLP data provided an insight into the phylogenetic relationship between ginger and other three species, with ginger being closest to Z. zerumbet. [ABSTRACT FROM AUTHOR]