Aneela Naz

Isolation of nematicidal compounds from Tagetes patula L. yellow flowers: structure-activity relationship studies against cyst nematode Heterodera zeae infective stage larvae.

Bioassay-guided isolation studies on the extracts of yellow flowers of Tagetes patula L. against the Heterodera zeae were carried out to identify phytochemicals lethal to this economically important cyst nematode. In vitro investigation of a polar extract and fractions showing activity led to the isolation of phenolic compounds (flavonoids and phenolic acids). In the nonpolar extract, a few fatty acids, their methyl esters, and thiophenes (including α-terthienyl) were detected. In studies of compounds obtained commercially, α-terthienyl and gallic and linoleic acids showed 100% mortality at concentrations of 0.125% after 24 h. Assessment of structure-activity relationships revealed that an increase in the number of hydroxyl groups in phenolic acids increased the activity; with fatty acids, activity depended on chain length and the number and position of double bonds. Crude extracts of the flowers of different colors also have promising activity.

Antibacterial and Antifungal Activities of Different Parts of Tagetes patula.: Preparation of Patuletin Derivatives

Abstract The current study evaluates the antibacterial and antifungal activities of extracts from different parts of Tagetes patula. Linn. (Asteraceae), reported for the first time in a single set of experiments. In the preliminary assay, the methanol extract of the flower (JFM) was found to possess antimicrobial activity against a number of bacteria with inhibition zone diameters ranging from 9 to 20 mm, the bioassay-guided fractionation of which led to the isolation of a flavonoid patuletin (3) in high yield as the active antibacterial principle with minimum inhibitory concentration (MIC) value of 12.5 μ g/disk against Corynebacterium. spp., Staphylococcus. spp., Streptococcus. spp., and Micrococcus luteus.. Its glucoside, patulitrin (4), was found to be weakly active, except against Staphylococcus saprophyticus., Streptococcus fecalis., and Streptococcus pyogenes. with inhibition zone diameters of 11, 16, and 12 mm, respectively. The cinnamate derivative (3b) of 3 showed antibacterial activity comparable with the parent flavonoid with a MIC value of 50 μ g/disk against Corynebacterium. spp., whereas benzoate derivative (3a) was found to be devoid of any activity; both the derivatives are new compounds. Moreover, the long-chain alcohol 5, which displayed antibacterial activity in the preliminary testing, was obtained in large quantity directly from the petroleum ether extract of the involucre of the flowers.

Jafrine, a novel and labile β-carboline alkaloid from the flowers of Tagetes patula

Abstract An inherently unstable and structurally novel tetrahydro β-carboline alkaloid, (+) jafrine ( 1 ) was isolated from the petroleum ether extract of Tagetes patula flowers. Its structure and stereochemistry has been determined with the help of spectroscopic analysis and the synthesis of racemate, (±) jafrine starting from available (±) tetrahydroharmine ( 2 ). The effect of solvent polarity on the ratio of amide rotamers of jafrine during NMR studies is discussed. The transformation of jafrine as well as 4- N -acetyl tetrahydroharmine ( 3 ), into 2-acetyl tryptamine derivatives by auto-oxidation was observed and its detail is presented. This process may be used as a synthetic tool for the preparation of tryptamine derivatives.

Bioassay-guided isolation of antioxidant agents with analgesic properties from flowers of Tagetes patula

Context: Tagetes patula L. is one of the French marigold group of the Asteraceae family. It is recognized in folklore for its medicinal and pesticidal properties. Objective: In search of more effective, but non-toxic compounds with antioxidative potential led to the bioassay guided isolation studies on the extracts of T. patula. Materials and methods: The bioassay on Tagetes patula flowers were carried out guided by in vitro antioxidant activity using DPPH assay. A minor but proven plant constituent methyl protocatechuate (1) was isolated by column chromatography, while patuletin (2) and patulitrin (3) obtained in bulk by employing solvent partition of methanol extract. Derivatization of patuletin into benzoyl, cinnamoyl and methyl was conducted to establish the structure activity relationship (SAR). Analgesic activity of compound 2 was evaluated using acetic acid-induced writhing test and hot-plate test in mice. The toxicity of methanol extract and compound 2 were also determined. Results: Polar extracts, fractions and phases demonstrated better antioxidant activity. The synthetic methyl protocatechuate (1) showed IC50 value of 2.8u2009±u20090.2u2009μg/mL, whereas patuletin (2) (IC50u2009=u20094.3u2009±u20090.25 µg/mL) was comparable to quercetin and rutin but significantly better than patulitrin (3) (IC50u2009=u200910.17u2009±u20091.16 µg/mL). Toxicity test for the methanol extract and compound 2 did not elicit any behavioral changes or cause mortality in mice. Compound 2 also demonstrated mild analgesic property. Discussion and conclusion: These findings demonstrate that the plant polar extracts and fractions possess significant antioxidant property with non-toxic effect. Compound 1 is a genuine plant constituent of T. patula.

Bioassay-guided studies on Bombax ceiba leaf extract: isolation of shamimoside, a new antioxidant xanthone C-glucoside

Bioassay-guided isolation studies on the methanolic extract of the leaves of Bombax ceiba employing DPPH antioxidant assay led to the isolation of a new xanthone C-glucoside, shamimoside (2), along with three known constituents, mangiferin (1), stigma-5-en-3-O-β-glucoside, and β-amyrin. The structure of shamimoside has been elucidated through extensive spectroscopic methods, including 1D and 2D NMR experiments, as 4-C-β-D-glucopyranosyl-1,3,6,8-tetrahydroxy-7-O-(p-hydroxybenzoyl)-9H-xanthen-9-one (2). It is the first naturally occurring xanthone containing a benzoate moiety directly attached to an aromatic ring. Polar extracts and fractions demonstrated better antioxidant activity, and 1 was found to be more potent than 2 in this assay.

New Terpenoids from the Roots of Melia azedarach

Two new terpenoids, bakayanolide (1) and 2α-hydroxy-3β-methoxy-6-oxo-13α,14β,17α-lanosta-7,24-dien-21,16β-olide (2), together with the known compounds 6β-hydroxy-3-oxo-13α,14β,17α-lanosta-7,24-dien-21,16β-olide (3), sendanolactone (4), kulactone (5), and β-sitosterol have been isolated from the ethanolic root extracts of Melia azedarach. Triterpenoids (4), (5), and β-sitosterol have been identified previously from M. azedarach, while it is the first instance of the isolation of (3) from this source. The identity of these compounds was established through extensive spectroscopic methods (infrared and mass spectroscopy, 1H and 13C nuclear magnetic resonance) as well as appropriate two-dimensional nuclear magnetic resonance experiments. Bakayanolide (1) belongs to the rare class of C11 odd terpenes. Compounds (3) and (4) possessed moderate cytotoxic activity against KB cell lines.

Host-Plant Effect on the Chemical Constituents of Cuscuta reflexa

0009-3130/17/5303-054