Antifungal activity of the stem bark of Ailanthus excelsa

The methanol extract of stem barks of Alianthus excelsa was partitioned with chloroform. The chloroform extract showed fungistatic and fungicidal activity against Aspergillus niger, A. fumigatus, Penicillium frequentence, P. notatum and Botrytis cinerea.     

Antifungal activity of Agapanthus africanus extractives

The ethanolic extract of the rhizomes of Agapanthus africanus showed antifungal activity. In bioassay guided fractionation, n-butanol fraction exhibited significant activity against human pathogens. A saponin, (25R)-spirost-7-en-2alpha,3beta,5alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1-->2)-[beta-D-galactopyranosyl (1-->3)] beta-D-glucopyranoside (1), responsible for the antifungal activity and having MIC value of 15.6 microg/ml against Trychophyton mentagrophytes and Sporothrix schenekii, was isolated and identified as active constituent of the plant.     

Antifungal activity of Aloe vera leaves

Aloe vera fresh leaves hydroalcoholic plant extract was tested against the mycelial growth of Botrytis gladiolorum, Fusarium oxysporum f.sp. gladioli, Heterosporium pruneti and Penicillium gladioli on Czapek-agar medium. The minimum fungicidal concentration (MFC) varied between 80 and 100 microl/ml, depending on the fungal species.     

Inhibition ofTrichoderma cellulase activity by a stilbene glucoside fromPicea glehnii bark

The stilbene glucoside isorhapontin (5,4-dihydroxy-3-methoxystilbene-3--D-glucoside) is the major constituent of the ethyl acetate extracts fromPicea glehnii bark. Isorhapontin inhibited the hydrolytic activity ofTrichoderma cellobiohydrolase I (CBH I) for both bacterial microcrystalline cellulose and the soluble cellooligosaccharide celloheptaitol. The inhibitory effect for celloheptaitol, however, was more drastic than that for bacterial microcrystalline cellulose. The hydrolytic activity of the CBH I core domain for celloheptaitol was also inhibited by isorhapontin to a similar extent, suggesting that the interaction between isorhapontin and the core domain of CBH I is the reason for this phenomenon. The inhibition of CBH I activity by isorhapontin showed mixed noncompetitive and uncompetitive types in a concentration of the inhibitor of less than 125M. TheK _i andK _i values were estimated to be 57.2 and 33.3M, respectively. Whereas isorhapontin strongly inhibited CBH I activity, its aglycone isorhapontigenin (3-methoxy-3,5,4-trihydroxystilbene) showed almost no inhibition. Consequently, both the stilbenic and the-glucosidic structures in isorhapontin are essential for the inhibitory effect on CBH I activity. Isorhapontin also inhibited the activity ofTrichoderma endoglucanase I for celloheptaitol, whereas almost no effect was observed for the activities of both endoglucanases II and III.An outline of this work was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999     

Antimicrobial activity of Andrographis paniculata

The antimicrobial activity of aqueous extract, andrographolides and arabinogalactan proteins from Andrographis paniculata were evaluated. The aqueous extract showed significant antimicrobial activity, which may be due to the combined effect of the isolated arabinogalactan proteins and andrographolides.     

Antifungal activities of compounds isolated from the leaves of Taxus cuspidata var. nana against plant pathogenic fungi

Antifungal activities of seven compounds, taxinine (1), paclitaxel (2), phenylisoserine methyl ester (3), sciadopitysin (4), ginkgetin (5), isorhamnetin (6), and quercetin (7), isolated from the leaves of kyaraboku, Taxus cuspidata var. nana, against five plant pathogenic fungi, Gibberella fujikuroi, Cladosporium cucumeninum, Fusarium oxysporum, Colletotrichum fragariae, and Corynespora cassiicola, were investigated for utilization of extractives from trees of the genus Taxus. Also, the amounts of compounds 2 and 3 on the leaf surface was measured in relation to the antifungal activities of compounds. Taxinine (1) showed antifungal activity against G. fujikuroi, C. cucumeninum, F. oxysporum, and C. cassiicola. The minimum inhibitory concentration of taxinine for the four fungi was 0.4mol. In addition, from the results of antifungal tests, it may be concluded that paclitaxel on the leaves and stem of T. cuspidata var. nana does not play an important role as an antifungicide in the resistance of trees to plant pathogenic fungal attack.     

Antifungal properties of methanol extract and its active compounds from Brickellia rosmarinifolia Vent

A new isocoumarin, 7-hydroxyl-4-methyl isocoumarine (1), together with three known monoterpenes, (3R, 4R, 6S)-3, 6-dihydroxy-1-menthene (2), (+)-(1R, 3S, 4R, 6S)-6-hydroxymenthol (3) and 4-isopropyl-1-methylcyclohex-2-ene-1, 6-diol (4), was isolated from the methanol extract of Brickellia rosmarinifolia. The structures were determined by spectroscopic means. Compounds 1, 2, 3 and 4 showed antifungal activities against Colletotrichum musae and Peronophythora litchii in vitro.     

Antimicrobial activity of aqueous extracts and of berberine isolated from Berberis heterophylla

The antimicrobial activity of Berberis heterophylla leaves, stems and root aqueous extracts was studied in vitro on Gram-positive and Gram-negative bacteria and fungi. The in vitro antifungal activity of berberine isolated from the same source against different Candida species was also investigated.     

Larvicidal activity of Cybistax antisyphilitica against Aedes aegypti larvae

The larvicidal activity against Aedes aegypti larvae of a stem wood hexane extract of Cybistax antisyphilitica was evaluated. Bioassay-guided fractionation of the crude extract, monitored by larvicidal assay, led to the isolation of a natural quinone identified as 2-hydroxy-3-(3-methyl-2-butenyl)-1.4-naphthoquinone (lapachol). This compound was quite potent against A. aegypti larvae (LC50 26.3 microg/ml).     

Larvicidal activity of a botanical natural product, AkseBio2, against Culex pipiens

A botanical natural product, AkseBio2, was evaluated for its larvicidal effect against Culex pipiens under laboratory conditions. The product exhibited strong larvicidal activity and caused >90% mortalities in both the young (first-second) and the older (third-fourth) larval stages of the species at 24 h at the doses of 25 and 50 ppm. However, it was determined that the young larval stages were more susceptible to the product in comparison with the older larval stages. The results suggest that the product is promising as a larvicide against C. pipiens and could be useful in the search of new larvicidal natural compounds.     

Insecticidal activity of some essential oils against larvae of Spodoptera littoralis

Thirty-four essential oils were tested for insecticidal activity (fumigation or topical application) against larvae Spodoptera littoralis. Twenty essential oils applied by fumigation were highly toxic to the third instar of S. littoralis larvae. Two essential oils Nepeta cataria and Thuja occidentalis were highly toxic, with LC50< or =10.0 ml/m3. Five essential oils Salvia sclarea, Thymus mastichina, Origanum majorana, Pogostemon cablin and Mentha pulegium were toxic with LC50 between 10.1 and 20.0 l ml/m3. Twenty-three essential oils were highly toxic to the third instar of S. littoralis larvae after topical application. Eight essential oils Mentha citrata, N. cataria, S. sclarea, O. vulgare, O. compactum, Melissa officinalis, T. mastichina, and Lavandula angustifolia were highly toxic with LD50 < or =0.05 microl/larvae.     

Antibacterial and antifungal activities of Breynia cernua

The Breynia cernua leaves, stem and root barks and heart-woods extracted with petrol, dichloromethane, ethyl acetate, butanol and methanol gave fractions with varied level of antimicrobial activity. The best activity was exhibited by the methanol extract of the root bark followed by its butanol fraction. These were the only fractions exhibiting a good level of antifungal activity as compared to the standard. The dichloromethane fraction of the stem bark also demonstrated good activity.     

Antibacterial activity of Abies webbiana

The methanol extract of the dried leaves of Abies webbiana was evaluated for antimicrobial activity. The methanol extract showed a broad spectrum of antibacterial activity.     

Antimicrobial activity of 2-arylbenzofurans from Morus species against methicillin-resistant Staphylococcus aureus

Nine 2-arylbenzofurans isolated from Morus species were tested for their antimicrobial activities against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Micrococcus luteus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Among these compounds, chalcomoracin (a leaf phytoalexine of mulberry tree) exhibited considerable antibacterial activity against MRSAs (MICs 0.78 μg/ml).     

Antimicrobial activities of Indian Berberis species

The antimicrobial activity of hydroalcoholic extracts of four Berberis species viz. Berberis aristata, Berberis asiatica, Berberis chitria and Berberis lycium were tested against eleven bacterial and eight fungal strains. B. aristata root extract gave low MICs values against Bacillus cereus, Escherichia coli, Staphylococcus aureus and Aspergillus flavus while stem extract against B. cereus and Streptococcus pneumoniae.     

Antibacterial and antifungal activities of Angiopteris evecta

The leaves, stem bark, stem heart wood, root and tubers of Angiopteris evecta were successively extracted with petrol, dichloromethane, ethyl acetate, butanol and methanol. All the fractions exhibited a wider spectrum of antibacterial activity. The dichloromethane and ethyl acetate fractions of the leaves and stem bark were particularly good and were the only fractions exhibiting antifungal activity. All fractions of the tuber with the exception of petrol, exhibited very good antibacterial activity.     

Antimicrobial activities and cytotoxicity of the brown alga Cystoseira tamariscifolia

The hexane, ethyl ether and dichloromethane fractions of the brown alga Cystoseira tamariscifolia extract showed interesting antimicrobial activities and cytotoxicity.     

Antibacterial and cytotoxic compounds from the bark of Cananga odorata

O-Methylmoschatoline, liriodenine and 3,4-dihydroxybenzoic acid isolated from the barks of Cananga odorata showed antibacterial activities against a number of Gram (+) and Gram (-) bacteria. The compounds also showed antifungal and cytotoxic activities.     

A laboratory study on the activity of <Emphasis Type="Italic">Steinernema feltiae</Emphasis> (Rhabditida: Steinernematidae) Rioja strain against horticultural insect pests

The potential of the entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) Rioja strain was assessed under laboratory conditions. Last instar larvae of Leptinotarsa decemlineata Say (Coleptera: Chrysomelidae), Spodoptera littoralis Boisdouval (Lepidoptera: Noctuidae) and Trichoplusia ni Hübner (Lepidoptera: Noctuidae) were exposed to infective juveniles (IJs) under laboratory conditions. Larval mortality, days to larval death, infection cycle length, and reproductive potential were recorded. Efficacy was assessed performing dose–response experiments. The results indicate that control of L. decemlineata with S. feltiae Rioja strain is not economically profitable (LC₅₀ = 99.61 IJs/cm²), whereas results obtained for T. ni (LC₅₀ = 0.27 IJs/cm²) are promising. Due to the life cycle of this insect, the efficacy needs to be investigated in foliar application studies. The effects on S. littoralis (LC₅₀ = 0.69 IJs/cm²) was considered the most suitable for development of the Rioja strain as a biocontrol agent for soil application.     

Leishmanicidal activity of Maytenus illicifolia roots

In vitro evaluation of leishmanicidal activity of aqueous and ethanolic extracts of Maytenus illicifolia against three species of Leishmania. The root extracts showed differential activity against parasites, whereas the aerial part of the extracts was inactive.