Combination of Piper guineense Essential Oil with Cowpea Varietal Resistance in Control of Cowpea Seed Beetle, Callosobruchus maculatus Fabricius (Coleoptera： Chrysomelidae： Bruchinae)

To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （PgEO） with cowpea varietal resistance in the control of cowpea seed beetle, Callosobruehus maculatus Fabricius. Four cowpea varieties （Sokoto, Drum, Oloyin and Gwallam） were studied. Data collected included oviposition, progeny emergence, Reproductive Efficiency （RE） and Percentage Seed Damage （PSD）. At first filial generation, numbers of eggs laid on Oloyin variety treated with 25 μL PgEO per 25 g cowpea seeds （2.15） were significantly （p〈0.05） lower than the values obtained in untreated cowpea （3.61） and hexane-treated seeds （3.07）. C. maculatus RE on Oloyin （33.73） was significantly （p〈0.05） lower than values obtained on other varieties （47.34-54.67） for seeds without PgEO; and were significantly greater than 0.00 observed on Oloyin seeds treated with 50 pL PgEO. PSD on Oloyin （6.63%） was significantly （p〈0.05） lower than the values obtained on Sokoto （10.04%） and Drum （9.79%） for seeds without PgEO, while there was no damage in Oloyin treated with 50 pL PgEO. Significantly （p〈0.05） lower F2 progeny emergence occurred on Oloyin （4.02） and Sokoto （4.71） compared with Drum （9.03） and Gwallam （6.07） from the untreated cowpea seeds. The results implied that application of PgEO to Oloyin gave better protection from infestation of C. maculatus than other varieties. Hence, combination of varietal resistance with PgEO for management ofbruchid could be an effective mean of improving cowpea food security.

First Isolation and Confirmation of Sterol Based on β-sitosterol Skeleton from the Leaves of Podocarpusnagi Planted in Fujian, Preliminary in vitro Anticancer Activity and the Crystal Structure

The crystal of(24 R)-3β,5α-dihydroxy-24-ethyl-5α-cholestan-6-one(1) was isolated from the leaves of P.nagi planted in Fujian for the first time with the same skeleton as 26,27-dinorcholest-5-en-3-β-ol(2) andβ-sitosterol(3) that have been reported before.Compound 1 crystallizes in monoclinic,space group P2_(1) with a=10.8482(4),b=7.3671(3),c=33.7860(15) A,β=93.103(4)°,V=2696.21(19) A^(3),Z=75,M_(r)=446.70,ρ_(calc)=1.145 g/cm^(3),F(000)=1032,μ=0.572 mm^(-1),GOOF=1.034,the final R=0.0467 and wR=0.1129 for 6989 observed reflections with I> 2σ(Ⅰ).Compound 2 was selected to evaluate for their preliminary in vitro anticancer activity against four cancer cell lines for the first time.The results showed that compound 2 exhibited great inhibition against gastric cancer,breast cancer MCF-7,lung cancer A549 and Helacell lines with the inhibitions of89.16% ± 1.17,97.02%±0.53,47.20%±2.58 and 36.89%±1.22 respectively at the concentration of 1.4×10^(-2) M,which means that we found the new anticancer compound in this plant medicine.