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| 1 | Cucurbitacin and Triterpenoid Glycosides from Hemsleya giganthy显示文摘From rhizomes of Hemsleya giganthy collected in Shichuan of China, 16 compounds were isolated. Among them, three compounds (8, 9, 15) are new natural products called Hemslecins G; Hemsgiganosides A and B; respectively. Their structures were elucidated as 7- hydroxy-23, 24-dihydro-cucurbitacin F-25-O-acetate (8); 3-O-(6-butyl ester-)-b-D-glu- curono- pyranosyl)-oleanolic acid-28-O-a-L-arabinopyranoside(9); 3-O-b-D-glucuropyranosyl oleanolic acid -28-O-b-D-gluco pyranosyl-(16)- b-D-glucopyranoside(15) by spectroscopic and chemical means. | YaCHEN MingHuaCHIU KunGU ZhongRongLI | 2003 | Chinese Chemical Letters2003，14，5： | 10 |
| 2 | Elemental Analysis of Fly and Bottom Ash from Burners/Incinerators in Selected Health Care Facilities in Kiambu County, Kenya显示文摘 | Raphael Kungu Paul Njogu Jackson Kiptoo | 2014 | Journal of Environmental Science and Engineering(A)2014，3，5： | 0 |
| 3 | Development of Novel Products from Agro-Wastes(Rice Husks)and Characterization in Kenya显示文摘Rice growing is a popular agricultural activity in some areas in Kenya.The challenge is in the disposal of RH(Rice Husks).Rice production results in 20%RH as byproduct.Simple incineration of RH results in RH ash which is a source of valuable chemical products.The ash is 87-97%silica,highly porous and light weight,with a very high external surface area.The end product of RHA(Rice Husk Ash)after chemical treatment,sodium silicate,is a precious commodity that has myriad applications especially in detergent manufacture and soap production.The objective was to determine the best conditions to synthesize silica from agro-wastes(RH)in Kenya.The yield(%SiO2)of the HCl(Hydrochloric Acid)leached RH at 500°C was the highest at 99.2%.Overall these conditions were the best in producing silicate.Percentage(%)removal of each metal is different due to its chemical form in RH.The removal percentage of K is especially remarkable.And 0.5 M HCl leaching followed by thermal treatment of 600°C gave the best increase in%silica dioxide.The same process removed the most metallic impurities(P2O5,K2O,CaO,Mn and Zn).Leaching with 0.5 M HCl followed with thermal treatment of 500°C gave the best overall yield in%silica dioxide.An increase in temperature from 600°C slightly reduced the%silica dioxide content.The 0.5 M HCl used in these trials was able to produce 99.17%silica content from the Mwea RH.The SiO2 obtained with the water washed RH sample is 97.37%as compared 99.17%(HCl-washed)and 99.02%(H2SO4(Sulphuric Acid)-leached).The FTIR(Fourier Transform Infrared Spectroscopy)spectra indicates HCl leaching avails more silica content than H2SO4 leaching. | Raphael Kungu Paul Njogu Robert Kinyua | 2019 | Journal of Environmental Science and Engineering(A)2019，8，1： | 0 |
| 4 | Green Chemistry Preparation and Characterization of Rice Husk Derived Silica Gel in Kenya显示文摘Rice is a grass seed from Oryza glaberrima species also known as the African rice.In Kenya,rice is mostly grown in Central(Mwea)and Nyanza(Ahero,West Kano,Migori and Kuria)areas.Milling rice produces rice husks as by-products which can be sources of valuable chemical products(silica gel,sodium silicate).In trials to produce silica gel from rice husks,rice husks were charred in a combustion chamber(30 min)then ashed in a Muffle furnace(Advantec KL-420)at different temperatures.The ashes were then leached with distilled water/acids to remove metal oxides.Sixty grams(60 g)of the leached RHA(Rice Husk Ash)was mixed with 300 mL of 3 M NaOH solution in a Pyrex 500 mL beaker and boiled at 100℃(1 h).The silica gel samples were characterized using several methods.Elemental analysis was done using TXRF(Total X-Ray Fluorescence),while FTIR(Fourier-Transform Infrared Spectroscopy)was used to obtain an infrared spectrum of absorption of the silica sample.Results of the analysis conform to local and international quality standards.The rice husks had an average moisture content of 7.07%and 1.00-2.00 mm diameter.And 1.74%of the rice husk had pore sizes of about 0.710 mm.The average ash content was 22.65%.At 600℃,leaching with water yielded 98.2%silica compared with 99.1%(H2SO4)and 96.9%(HCl).At 500℃,leaching with HCl/H2SO4 causes a decrease.At 500℃,the availability of SiO2 is more for water leached samples.At 400℃,water leaching gave 98.49%silica while HCl leaching was 97.85%silica and H2SO4 was 99.41%.Silica is a precursor of silica gel.Statistical analyses imply water leaching RHA instead of acid leaching at 500℃ will produce a significant amount of silica gel.The open burn samples produced equal or better SiO2(silica gel precursor)yields compared with the incineration samples.FTIR analysis of the silica gel sample compared well with adsorption peaks of silica gel in literature.XRD(X-Ray Diffraction)analysis produced a pattern consistent with other XRD patterns of silica gel published by other researchers. | Raphael Kungu Paul Njogu Robert Kinyua Jackton Kiptoo | 2019 | Journal of Environmental Science and Engineering(A)2019，8，6： | 0 |
| 5 | A New Taxoid from Leaves and Branches of Taxus chinensis显示文摘A new taxoid, 2-deacetyl-2a, 14b-dihydroxybaccatin IV (1), was isolated from the leaves and branches of Taxus chinensis together with the known compound baccatin IV (2). The structure of the new compound was elucidated by spectroscopic techniques. The detailed 13C NMR assignments of baccatin IV are reported for the first time. | FuShengWANG LiYanPENG YuZHAO QinShiZHAO KunGU HanDongSUN | 2004 | Chinese Chemical Letters2004，15，3： | 0 |
| 6 | Ongoing green peafowl protection in China显示文摘DEAR EDITOR,The green peafowl (Pavo muticus) is one of the most threatened pheasants in the world. In China, it is widely appreciated for its beauty as well as historical and cultural value, but current populations number less than 500 individuals. Recently, Tang and colleagues reported in Science that the green peafowl is likely to become extinct due to the construction of the Jiasajiang Level 1 Hydropower Station within the Red River Upstream District (RRUD) and thus called for a stop to this project (Tang et al., 2019). According to our recent surveys, however, this species is still extant in 22 counties of Yunnan Province, China, among which, only two within the RRUD have been predicted to be affected by floods from the hydropower station. Therefore, the conclusion that the species will likely go extinct in China upon completion of the dam is unwarranted. In fact, construction of the Jiasajiang Level 1 Hydropower Station was stopped in August 2017. The main challenge for green peafowl conservation is that over 65% of the population occurs outside of protected reserves in China. Fortunately, the Chinese government has adopted an Ecological Redline (ERL) strategy to achieve ecological civilization plans, thus bringing new hope to the conservation of green peafowls both inside and outside of protected reserves. As a top conservation priority for China, the government is fully committed to conserving this peafowl. | Fei Wu De-Jun Kong Peng-Fei Shan Jie Wang Gladys Nyakeru Kungu Guang-Yi Lu Xiao-Jun Yang | 2019 | Zoological Research2019，40，6： | 0 |
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