Chemical composition and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of cassumunar-ginger.

BACKGROUND: Zingiber montanum (J.Koenig) Link ex A.Dietr. (Zingiberaceae), commonly known as cassumunar-ginger, is a folk remedy for the treatment of inflammations, sprains, rheumatism and asthma. The aim of the present study was to assess the chemical composition, and antibacterial, antifungal, allelopathic and acetylcholinesterase inhibitory activities of the essential oil of Z. montanum originating from India. RESULTS: The hydrodistilled essential oil of Z. montanum rhizome was analyzed using gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. A total of 49 constituents, forming 98.7-99.9% of the total oil compositions, was identified. The essential oil was characterized by higher amount of monoterpene hydrocarbons (32.6-43.5%), phenylbutanoids (27.5-41.2%) and oxygenated monoterpenes (11.4-34.1%). Major constituents of the oil were sabinene (13.5-38.0%), (E)-1-(3',4'-dimethoxyphenyl)buta-1,3-diene (DMPBD) (20.6-35.3%), terpinen-4-ol (9.0-31.3%), γ-terpinene (1.1-4.8%) and ß-phellandrene (1.0-4.4%). The oil was evaluated against eight pathogenic bacteria and two fungal strains. It exhibited low to good antibacterial activity (minimum inhibitory concentration: 125-500 µg mL-1 ) and moderate antifungal activity (250 µg mL-1 ) against the tested strains. The oil reduced germination (69.8%) and inhibited the root and shoot growth of lettuce significantly (LD50 : 3.58 µL plate-1 ). However, it did not demonstrate acetylcholinesterase inhibitory activity up to a concentration of 10 mg mL-1 . CONCLUSIONS: The essential oil of Z. montanum can be used as a potential source of DMPBD, terpinen-4-ol and sabinene for pharmaceutical products. The results of the present study add significant information to the pharmacological activity of Z. montanum native to India. © 2017 Society of Chemical Industry.

Chemical Composition and Allelopathic, Antibacterial, Antifungal, and Antiacetylcholinesterase Activity of Fish-mint (Houttuynia cordataThunb.) from India.

Fish-mint (Houttuynia cordataThunb.), belonging to family Saururaceae, has long been used as food and traditional herbal medicine. The present study was framed to assess the changes occurring in the essential-oil composition of H. cordata during annual growth and to evaluate allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities. The essential-oil content ranged from 0.06 - 0.14% and 0.08 - 0.16% in aerial parts and underground stem, respectively. The essential oils were analysed by GC-FID, GC/MS, and NMR (1 H and 13 C). Major constituents of aerial-parts oil was 2-undecanone (19.4 - 56.3%), myrcene (2.6 - 44.3%), ethyl decanoate (0.0 - 10.6%), ethyl dodecanoate (1.1 - 8.6%), 2-tridecanone (0.5 - 8.3%), and decanal (1.1 - 6.9%). However, major constituents of underground-stem oil were 2-undecanone (29.5 - 42.3%), myrcene (14.4 - 20.8%), sabinene (6.0 - 11.1%), 2-tridecanone (1.8 - 10.5%), ß-pinene (5.3 - 10.0%), and ethyl dodecanoate (0.8 - 7.3%). Cluster analysis revealed that essential-oil composition varied substantially due to the plant parts and season of collection. The oils exhibited significant allelopathic (inhibition: 77.8 - 88.8%; LD50 : 2.45 - 3.05 µl/plate), antibacterial (MIC: 0.52 - 2.08 µl/ml; MBC: bacteriostatic) and antifungal (MIC: 2.08 - 33.33 µl/ml; MFC: 4.16 - 33.33 µl/ml) activities. The results indicate that the essential oil from H. cordata has a significant potential to allow future exploration and exploitation as a natural antimicrobial and allelopathic agent.