Nitin Sati

Bioactive constituents and medicinal importance of genus Alnus.

The genus Alnus has been reviewed for its chemical constituents and biological activities including traditional importance of some common species. The plants of this genus contain terpenoids, flavonoids, diarylheptanoids, phenols, steroids, and tannins. Diarylheptanoids are the dominant constituents within the genus Alnus, few of them exhibited antioxidant effects and inhibitory activity against nuclear factor kappaB activation, nitric oxide and tumor necrosis factor-α production, human umbilical vein endothelial cells, farnesyl protein transferase, cell-mediated low-density lipoprotein oxidation, HIF-1 in AGS cells, and the HIV-1-induced cytopathic effect in MT-4 cells. Some ellagitannines showed hepatoprotective activity even in a dose of 1 mg/kg which is ten-fold smaller compared with the dose of traditional flavonoid-based drugs. The members of genus Alnus are well known for their traditional uses in the treatment of various diseases like cancer, hepatitis, inflammation of uterus, uterine cancer, rheumatism, dysentery, stomachache, diarrhea, fever, etc. The aim of the present review is to summarize the various researches related to the chemistry and pharmacology of genus Alnus.

Chemical composition and antifungal activity of Artemisia nilagirica essential oil growing in northern hilly areas of India

Essential oil extracted from aerial parts of Artemisia nilagirica was analysed by gas chromatography–mass spectroscopy. Forty-three constituents amounting to 98.16% of the total essential oil contents were identified. The essential oil contained approximately 79.91% monoterpenoids and 18.25% sesquiterpenoids. α-Thujone (36.35%), β-thujone (9.37%), germacrene D (6.32%), 4-terpineol (6.31%), β-caryophyllene (5.43%), camphene (5.47%) and borneol (4.12%) were identified as the major constituents. The essential oil exhibited significant antifungal activity against Rhizoctonia solani (ED50, 85.75 mg L−1), Sclerotium rolfsii (ED50, 87.63 mg L−1) and Macrophomina phaseolina (ED50, 93.23 mg L−1). This study indicated that A. nilagirica essential oil can be used to control phytopathogenic fungi infesting agricultural crops and commodities.

Synthesis and biological evaluation of Schiff bases and azetidinones of 1-naphthol

Introduction: Schiff bases and azetidinones form an important structural class possessing wide spectrum of biological activities that include antibacterial and antifungal activity. A series of Schiffs bases N’-(substituted benzylidene)-2-(naphthalen-1-yloxy) acetohydrazides (3a-f) and azetidinones N-[3-chloro-2-oxo-4-(substituted phenyl)-azetidin-1-yl]-2-(naphthalen-1-yloxy) acetamides (4a-b) were synthesized and tested for antimicrobial activity. Materials and Methods: The chemical structures of synthesized compounds were elucidated on the basis of IR and 1H NMR spectroscopy. The synthesized compounds were screened for antibacterial activity against E. coli (ESS 2231) and B. subtilis (MTCC 441). The compounds were also tested for antifungal activity against A. niger (NCIM 618) and C. albicans (NCIM 3557) by the cup diffusion method. Results and Discussion: The in vitro antimicrobial activity results showed that the N-[3-chloro-2-oxo-4-(4-substitutedphenyl)-azetidin-1-yl]-2-(naphthalen-1-yloxy) acetamides (4a-b) exhibited better antibacterial activity than the synthesized N′-(substituted benzylidene)-2-(naphthalen-1-yloxy)-acetohydrazides (3a-f). Compound (4b) displayed potent antibacterial activity against the B. subtilis and E. coli (MIC values of 16-64 μg/mL). The antifungal activity of the synthesized compounds (3a-f and 4a-b) against the A. niger and C. albicans was relatively weak, most of the compounds showed poor activities (MIC >128μg/mL). Conclusion: The antibacterial activity of the synthesized compounds was moderate to low and antifungal activity was relatively weak. Therefore, a further study with this class of compounds is necessary to elucidate the mechanism and structure activity relationship.

Antifungal and phytotoxic activity of essential oil from root of Senecio amplexicaulis Kunth. (Asteraceae) growing wild in high altitude-Himalayan region

Abstract This work was aimed to evaluate the essential oil from root of medicinally important plant Senecio amplexicaulis for chemical composition, antifungal and phytotoxic activity. The chemical composition analysed by GC/GC–MS showed the presence of monoterpene hydrocarbons in high percentage with marker compounds as α-phellandrene (48.57%), o-cymene (16.80%) and β-ocimene (7.61%). The essential oil exhibited significant antifungal activity against five phytopathogenic fungi, Sclerotium rolfsii, Macrophomina phaseolina, Rhizoctonia solani, Pythium debaryanum and Fusarium oxysporum. The oil demonstrated remarkable phytotoxic activity in tested concentration and significant reduction in seed germination percentage of Phalaris minor and Triticum aestivum at higher concentrations. The roots essential oil showed high yield for one of its marker compound (α-phellandrene) which makes it important natural source of this compound. Graphical abstract

Chemical composition and antimicrobial activity of fatty acid methyl ester of Quercus leucotrichophora fruits.

Abstract Natural fats and dietary oils are chief source of fatty acids and are well known to have antimicrobial activities against various microbes. The chemical composition and antimicrobial activities of fatty acids from fruits of white Oak (Quercus leucotrichophora) are yet unexplored and therefore the present study for the first time determines the fatty acid composition, and the antibacterial and antifungal activities of fatty acid methyl esters (FAME) of the white Oak plant found along the Himalayan region of Uttarakhand, India. The GCMS analysis revealed the presence of higher amount of saturated fatty acids than unsaturated fatty acids. FAME extract of fruits of Q. leucotrichophora demonstrated better antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. The present studies clearly establish the potential of the fruits of Q. leucotrichophora for use in soap, cosmetics and pharmaceutical industries.

Analysis and antimicrobial activity of volatile constituents from Quercus leucotrichophora (Fagaceae) bark

The chemical composition of the volatile extract (yield ≈0.13%, v/w) from the bark of Quercus leucotrichophora (Fagaceae) was analysed for the first time by GC–MS. Twenty-three constituents, amounting to 93.0% of the total detected contents of the volatile extract, were identified. The volatile extract contained approximately 86.36% monoterpenoids, 6.53% sesquiterpenoids and 0.11% aliphatic aldehydes. 1,8-Cineol (40.359%) followed by γ-terpinene (16.369%) were the major monoterpene constituents of the volatile extract. The residue of volatile extract (0.00025–250 µg mL−1) exhibited a potent antimicrobial activity against Streptococcus pyogenes ATCC 19615. This study concludes that residues of the volatile extract of Q. leucotrichophora could serve as an important bioresource for the extraction and isolation of monoterpenoids exhibiting antimicrobial activity, and thus has good potential for use in the pharmaceutical industry.

Isolation and Characterization of “Flavon-5, 3’, 4’- Trihydroxy 7-O-β-D-glucopyranosyl (6’’→1’’’) β-D-glucopyranoside” from Stem Bark of Quercus Leucotrichophora

A flavonoidal glycoside, named flavon-5, 3’, 4’-trihydroxy 7-O-β-D-glucopyranosyl (6’’→1’’’) β-D-glucopyranoside, has been isolated from the stem bark of Quercus leucotrichophora, together with β-sitosterol, kaempferol, quercetin and 7-methoxy kaempferol. The structure of flavon-5, 3’, 4’-trihydroxy 7-O-β-D-glucopyranosyl (6’’→1’’’) β-D-glucopyranoside, by means of rigorous spectroscopic analysis including 2-D NMR measurements.