Professor Dr. Gomah Nenaah

Four prenylated flavonoids, isoglabratephrin, (þ)-glabratephrin, tephroapollin-F and
lanceolatin-A, were isolated from Tephrosia apollinea L. and tested against three
stored grain insects. Using the filter paper bioassay, compounds showed adulticidal
activity against Sitophilus oryzae (L), Rhyzopertha dominica (F) and Tribolium
castaneum (Herbst) at concentrations of 0.875, 1.75 and 3.5 mgmL21. At 3.5 mgmL21,
tephroapollin-F was the most toxic (78.6%, 64.6% and 60.7% mortality was recorded
after 10 days exposure of S. oryzae, R. dominica and T. castaneum, respectively). The
F1 progeny production of insects was affected after parental exposure to flavonoids,
where S. oryzae was the most susceptible. A nutritional bioassay, employing a flour
disc and test concentrations of 0.65, 1.3 and 2.6 mg g21, revealed a significant reduction
in the relative growth rate, relative consumption rate and efficiency of conversion of
ingested food by all insects. The structure–activity relationship among the tested
flavonoids was discussed.

The total glycoalkaloid fraction (TGA) and the two glycoalkaloids, a-chaconine and a-solanine of potato,
Solanum tuberosum, were isolated. Their toxic and antifeedant activities against the Khapra beetle,
Trogoderma granarium Everts were investigated. Results indicated considerable toxicity, especially when
adults were topically treated with the glycoalkaloids. The TGA fraction was the most toxic with LC50’s of
16.7 and 11.9 mg/mg insect, 48 and 96 h post treatment, respectively. LC50’s of a-chaconine and a-solanine
96 h post treatment were 18.1 and 22.5 mg/mg insect, respectively. Moderate toxicities were recorded
when insects were confined on dry-film residues of botanicals with LC50’s ranging between 26.1 and
56.6, and 19.4 and 45.7, mg/cm2 48 and 96 h post treatment, respectively. Nutritional studies using the
flour disc bioassay revealed significant reduction in the growth rate (RGR), food consumption rate (RCR)
and food utilization (ECI) by T. granarium at concentrations ranging between 20 and 30 mg g
1 food with
feeding deterrent indices reaching 82.4% with the TGA fraction. When tested as binary or crude alkaloidal
mixtures, toxic and antifeedant activities of glycoalkaloids were increased, indicating some additive
interaction among these botanicals. There is potential for use of such compounds to protect stored grains
from insect infestation.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright

In the current study, probit and logistic models were employed to fit experimental mortality data of the Khapra beetle, Trogoderma granarium (Everts) (Coleoptera: Dermestidae), when fumigated with three plant oils of the gens Achillea. A generalized inverse matrix technique was used to estimate the mortality model parameters instead of the usual statistical iterative maximum likelihood estimation. As this technique needs to perturb the observed mortality proportions if the proportions include 0 or 1, the optimal perturbation in terms of minimum least squares (L 2) error was also determined. According to our results, it was better to log-transform concentration and time as explanatory variables in modeling mortality of the test insect. Estimated data using the probit model were more accurate in terms of L 2 errors, than the logistic one. Results of the predicted mortality revealed also that extending the fumigation period could be an effective control strategy, even, at lower concentrations. Results could help in using a relatively safe and effective strategy for the control of this serious pest using alternative control strategy to reduce the health and environmental drawbacks resulted from the excessive reliance on the broadly toxic chemical pesticides and in order to contribute safeguard worldwide grain supplies.

Essential oils of Achillea biebersteinii, A. santolina and A. mellifolium were obtained by hydrodistillation, then analyzed using gas chromatography (GC) and GC/mass spectrometry (MS). The obtained oils showed considerable toxic and growth inhibitory activities against the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The time of exposure, the technique used and the stage treated, all were activity-determinant factors, where A. biebersteinii oil showed the strongest insecticidal activity and the adult stage was more susceptible than larvae. Using topical application, LC 50 values of A. biebersteinii, A. santolina and A. mellifolium oils after 96 h of exposure of larvae were 30.3, 47.8 and 62.3 g/mg insect, respectively. In this case, LC 50s against adults were ranged between 21.8 and 50.7 g/mg insects. Using treated filter papers, the LC 50 values after 96 h of exposure against larvae were ranged between 124.9 and 212.0 L/cm 2 , while against adults were ranged between 113.0 and 196.8 L/cm 2. In the fumigant bioassay, LC 50s after 96 h of exposure against larvae were between 41.7 and 93.2 L/L air, while against adults were between 36.1 and 80.6 L/L air. When prepared as nano-emulsions and tested as fumigants, toxicity of oils was increased dramatically, where LC 50 values after 96 h of exposure against larvae and adults were ranged between 11.0 and 27.5 L/L air and 8.8 and 21.3 L/L air, respectively. When exposed as 2nd instar larvae to sub-lethal doses-treated grains, the developmental course, life span and F 1 progeny of T. castaneum were significantly affected, where the oil of A. santolina showed the strongest activity. All of these developmental disruptions led to a great reduction in the number of adults that undergo successful emergence.

Essential oils of Achillea biebersteinii, Achillea
santolina and Achillea mellifolium were obtained by hydrodistillation
and analyzed using gas chromatography/mass
spectrometry. The plant oils were tested for their toxic and
repellent activities against the Khapra beetle, Trogoderma
granarium (Everts) (Coleoptera: Dermestidae). T. granarium
was sensitive to the oils via topical application,
contact and fumigation bioassays, where A. biebersteinii
oil was the most toxic regardless of the technique used.
Using topical application, a dosage of 15 lg/mg insect of
A. biebersteinii oil was sufficient to kill 100 and 83.2.0 %
after 7 days exposure of adults and 2nd instar larvae,
respectively. Meanwhile, twice this concentration of A.
santolina and A. mellifolium oils caused 90.4 (72.5 %) and
73.8 (60.1 %) adult and larval mortality after 7 days,
respectively. Using fumigation and 7 days exposure, a
concentration of 50.0 ll/l air of A. biebersteinii oil displayed
the strongest activity (percentage adult and larval
mortalities of 100.0 and 88.0 %), respectively, while A.
santolina and A. mellifolium oils at the same concentration
caused 92.5 (76.8 %) and 76.1 (61.3 %) adult and larval
mortality, respectively. The three oils were strongly
repellent to the larvae and adults of T. granarium. The
repellent activity was time and concentration-dependent,
where A. biebersteinii oil was the most effective, even
though at low concentrations (percentage repellency of
100 and 81.0 % were recorded against adults and larvae
after 6 h exposure to a concentration of 0.22 ll/cm2,
respectively). Results suggested the potential use
of Achillea oils as natural grain protectants against
T. granarium.

Essential oils from three local plants Ageratum conyzoides, Achillea fragrantissima and Tagetes minuta were obtained by hydrodistillation and analyzed using gas chromatography (GC) and GC/mass spectrometry (MS). Nanoemulsions from the obtained oils were prepared using the High Pressure Homogenization (HPH) technique. The plant oils showed considerable ovicidal, adulticidal and residual activities against the cowpea beetle, Callosobruchus maculatus, where A. conyzoides oil was the most toxic. Following a 24-h fumigation and a 48-h post exposure period, eggs were less susceptible to the oils than adults, where LC 50's ranged from 71.6 to 161.9 ml/l air and 19.2e77.8 ml/l air against eggs and adults, respectively. When mortality was counted 96 h after treatment, susceptibility of all stages was increased. When prepared as nanoemulsions and tested as fumigants, toxicity of oils was increased dramatically, where LC 50 values 96 h after treatment ranged from 16.1 to 40.5 ml/l air and 4.5e24.3 ml/l air against eggs and adults, respectively. In a contact toxicity bioassay, adults were susceptible to the oil-treated filter papers, where LC 50's 96 h after treatment ranged between (37.1e110.8 ml/cm 2). When mixed with kaolin powder and tested as contact adulticides, activity of oils increased compared with their application alone. The plant oils showed a weak to moderate residual adulticidal activity, where A. conyzoides oil was the most effective. The study shows the potential of new ways of using the tested plant oils as natural grain protectants after the required toxicological assessments.

Powders and essential oils were prepared from the aerial parts of Cinnamomum camphora, Ocimum basilicum, Chenopodium ambrosioides, and seeds of Pimpinella anisum. Their adulticidal activities and effects on the F 1 progeny of Trogoderma granarium (Everts) and Tribolium castaneum (Herbst) were evaluated. The chemical composition of the plant oils were identified by gas chromatography (GC) and GC/mass spectrometry (MS). All of the tested botanicals showed insecticidal activities against the test insects in a dose-dependent manner with T. granarium was more susceptible to the tested plant products than T. castaneum. At a concentration of 5 g kg-1 , many of the plant powders caused 100% mortality of both insects after 14 days of exposure. The powders of C. cam-phora, O. basilicum, and C. ambrosioides were effective against T. granarium, while that of C. ambrosioides caused 100% adult mortality of T. castaneum under the same assays conditions. A dose of 1.50 ml cm-2 of the oils of C. cam-phora and O. basilicum completely controlled T. granarium, while 100% mortality of T. castaneum adults was recorded with P. anisum oil. A significant and/or complete reduction (100% inhibition) of the F 1 progeny of both insects was obtained as a result of parental exposure to the tested botanicals, especially at the highest doses applied. Botani-cals under investigation showed a considerable grain protecting activity against the tested insect species and could be included in integrated pest management (IPM) strategies.

Essential oils (EOs) of Achillea biebersteinii, Achillea fragrantissima, Achillea santolina and Achillea mil-lefolium were obtained by hydrodistillation and analyzed using Gas Chromatography (GC) and GC/Mass Spectrometry (MS). Nanoemulsions from EOs and major fractions were prepared using the High Pressure Homogenization technique (HPH). EOs and their nanoemulsions were tested for their antibacterial activity against two Gram-positive foodborne bacteria (Staphylococcus aureus and Listeria monocytogenes) and three Gram-negative species (Escherichia coli, Pseudomonas aeruginosa and Salmonella enteritidis). The Gram-positive bacteria were more susceptible than the Gram-negative ones, where P. aeruginosa was the most resistant. A plant oil was also more active than its major components and the oils of A. bie-bersteinii and A. fragrantissima were the most active regardless of the microorganism tested (diameter of inhibition zones ranged between 6.0 and 21.5 mm). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) ranged between 60.0 and 480.0 mg/ml. When tested as nanoemulsions, activity of EOs and fractions was increased dramatically (diameter of inhibition zones reached 34.5 mm and (MIC) and (MBC) reached 15.0 mg/ml with A. biebersteinii nanoemulsions against S. aureus). The study recommends the use of the test plant oils as antimicrobial biorationals, especially at their nanoscale after the required toxicological assessments.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Antimicrobial activity of solvent extracts and
flavonoids of Calotropis procera growing wild in Saudi
Arabia was evaluated using the agar well-diffusion method.
A bioassay-guided fractionation of the crude flavonoid
fraction (Cf3) of MeOH extract which showed the highest
antimicrobial activity led to the isolation of four flavonoid
glycosides as the bioactive constituents. Structure of compounds
have been elucidated using physical and spectroscopic
methods including (UV, IR, 1H, 13C-NMR, DEPT, 2D
1H–1H COSY, HSQC, HMBC and NOESY). Compounds
were found to be the 3-O-rutinosides of quercetin, kaempferol
and isorhamnetin, besides the flavonoid 5-hydroxy-3,7-
dimethoxyflavone-40-O-b-glucopyranoside. Most of the isolated
extracts showed antimicrobial activity against the test
microorganisms, where the crude flavonoid fraction was the
most active, diameter of inhibition zones ranged between
15.5 and 28.5 mm against the tested bacterial strains, while
reached 30 mm against the fungal Candida albicans. The
minimal inhibitory concentrations varied from 0.04 to
0.32 mg/ml against all of the tested microorganisms in case
of the crude flavonoid fraction. Quercetin-3-O-rutinoside
showed superior activity over the remainder flavonoids. The
Gram-positive bacteria (Staphylococcus aureus and Bacillus
subtilis) were more susceptible than the Gram-negative
(Pseudomonas aeruginosa and Salmonella enteritidis) and
the yeast species were more susceptible than the filamentous
fungi. The study recommend the use of such natural products
as antimicrobial biorationals.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights a b s t r a c t Four prenylated flavonoids, isoglabratephrin, (þ)-glabratephrin, tephroapollin-F and lanceolatin-A were isolated from Tephrosia apollinea L. growing in Egypt. The structures of compounds have been elucidated using physical and spectroscopic methods including (UV, IR, 1 H NMR, 13 C NMR, DEPT, 2D 1 He 1 H COSY, HSQC, HMBC and NOESY). The isolated flavonoids showed considerable antifungal activity against four phytopathogenic fungi, namely Alternaria alternata, Helminthosporium sp., Colletotrichum acutatum and Pestalotiopsis sp. in a dose-dependent manner using the agar well-diffusion bioassay. They differ significantly in their activity with tephroapollin-F was the most effective. In a test using a concentration of 4 mg/ml of tephroapollin-F, strong fungicidal activities (32.8e58.3%) were produced against the test fungi, where C. acutatum, Helminthosporium sp. and Pestalotiopsis sp. showed greater susceptibility, while A. alternata was the least susceptible. Using the same concentration, the two flavonoids isoglabratephrin and (þ)-glabratephrin showed moderate activities with % inhibition of fungal growth were ranged between (16.1e37.8) against A. alternata, Helminthosporium sp. and Pestalotiopsis sp., while showed a strong antifungal activity against C. acutatum (% growth inhibition were 46.4 and 42.9, respectively). In all treatments, the flavonoid lanceolatin-A exhibited weak to moderate activities. Using lower concentrations of the test flavonoids (2 and 1 mg/ml), weak to moderate antifungal activities were observed against all of the test fungal strains. In all cases and regardless of the flavonoid tested, C. acutatum was the most susceptible, while A. alternata was the least. The study recommends the use of the test compounds as rational fungicides of natural origin.

The β-carboline alkaloids of Peganum harmala L were extracted through a bioassay-guided fractionation and their antimicrobial activities were investigated. Results revealed significant differences (P N 0.05) between compounds depending on the microorganism tested and the application method. When examined individually, harmine was the most effective against Proteus vulgaris, Bacillus subtilis and Candida albicans where inhibition zones ranged between 21.2 and 24.7 mm. Potentiality of the alkaloids was increased when applied as binary mixtures suggesting a kind of synergistic interaction with inhibition zones reaching 31.5 mm with the total alkaloidal extract. We recommended the use of such compounds as new antimicrobial biorationals.