PROF. NJENGA LYDIAH W

Doctor of Philosophy (PhD) in Analytical/Environmental Chemistry.

Master of Science (MSc) In Chemistry.

Bachelor of Science (BSc) Chemistry Major

lnjenga@uonbi.ac.ke 

UNIVERSITY OF NAIROBI

Department of Chemistry

https://profiles.uonbi.ac.ke/lnjenga/

LYDIA WANJIRU NJENGA

Address: Department of Chemistry
University of Nairobi,
P. O. Box 30197-00100,
NAIROBI.
Tel: 254-204446138 (office)
254-722-768245 (mobile)
E-Mail lnjenga@uonbi.ac.ke


RESEARCH INTERESTS
Water Chemistry, Water Quality Monitoring and Risk Assessment, Water Purification
and Treatment. Defluoridation of water, Solid waste Management and Treatment,
Environmental Chemistry, Development of Analytical Methods for fluoride and other
anions in different samples, Bioavailability of trace elements, coordination chemistry
Occupation Healthy and Safety issues,


EDUCATIONAL BACKGROUND
1985 – 1990 University of Nairobi, Doctor of Philosophy (PhD) in Analytical/Environmental
Chemistry.
1979–1982 University of Nairobi, Master of Science (MSc) in Chemistry.
1976- 1979 University of Nairobi, Bachelor of Science (BSc) Chemistry Major (1st class
honors)
1985-1986 University of Uppsala (Sweden), Diploma in Analytical Chemistry

1974-1975 Alliance Girls High School, Kenya Advanced Certificate of Education
1970-1973 Ngandu Girls High School, Kenya Certificate of Secondary Education.

WORKING EXPERIENCE
16th November 2012 – to date: Dean, School of Physical Sciences2
3
rd January 2011 – 15th Nov 2012: Acting Dean, School of Physical Sciences
2006 – To date: Associate professor of Chemistry, Department of Chemistry
1994 – August 2006 Senior lecturer, University of Nairobi
1987 – 1993 Lecturer, University of Nairobi
1983 – 1987 Tutorial Fellow, Department of Chemistry, University of Nairobi
1982 – 1983 Demonstrator, Department of Chemistry, University of Nairobi
1979 Research Chemist, Ministry of Natural Resources (Mines and Geology)
1976 Teaching (Mathematic and Chemistry), Gatanga Girls secondary School.


see..........https://profiles.uonbi.ac.ke/lnjenga/files/prof__njenga_cv_doc7__09-01-2015.pdf

Professor Lydia Wanjiru Njenga, PhD

Professor Lydia Wanjiru Njenga  Dean School of Physical Sciences (Pictured) was appointed the Director, Board of Postgraduate Studies, University of Nairobi for a term of three years with effect from January 2, 2015.

The appointment was contained in a letter dated January 2, 2015 and signed by the Vice Chancellor, Professor George A. O. Magoha. Prof. Njenga replaces Prof. Eunice W. Mutitu whose second term as director of the Board of Postgraduate Studies expired on January 2, 2015 after serving for six years.

A holder of a Doctor of Philosophy in Analytical/ Environmental Chemistry, Prof. Njenga was tyhe Dean School of Physical Sciences, is an associate professor in the department of Chemistry having risen through academic levels since 1983 when she first joined the department as a Tutorial Fellow. Prof. Njenga brings along with her a wealth of academic and administrative experience, having served as Dean, School of Physical Sciences. She has also served in several college and faculty committees and was the advisor to the Nairobi University Chemical Club, among other responsibilities.

Prof. Njenga has been Dean School of Physical Sciences For Four years,an external examiner in several local and international universities and has supervised two PhD candidates, several Masters and undergraduate students to completion. Her research interest is in Fluoride analysis in water, foods, plants and soils and coordination Chemistry. She has attended 40 local and international conferences and workshops and presented 14 papers and six reports. Prof. Njenga is widely published with 16 articles in Refereed Journals and has authored two Open and distance learning Modules entitled, “Coordination Chemistry”  and  “Transition Elements (d and f block elements)  and Organometallic Chemistry”.

Prof. Njenga is a member of Kenya Chemical Society, Women in Science and Engineers, Women in Chemistry, Kenya DAAD Association and East and Southern Africa Environmental Chemistry. She engages in several community service initiatives.

The Fountain of Knowledge at the University of Nairobi. 













NAIROBI



PUBLICATIONS
1. C. Muhavini Wawire, , Damien Jouvenot, Frédérique Loiseau, Pablo Baudinb,
Sébastien Liatard, Lydia Njenga, Geoffrey N. Kamau, Mark E. Casida Densityfunctional
study of luminescence in polypyridineruthenium complexes. Journal of
Photochemistry and Photobiology A: Chemistry 276, (2013) 8– 15
2. David M. Maina, Lydia W. Njenga, John M. Onyari, Banjamin N. Kyalo, Trace Elements
Concentration in Some Tradition Diets Consumed in Selected Parts of Eastern Province of
Kenya Journal of environmental protection 3, ( 2012) 617-623
3. Njenga, L. W., Maina, D. M., Kariuki, D. N. and Mwangi, F. K., Aluminium exposure
from Vegetables and Fresh raw vegetable Juices. Journal of Food Agriculture and
Environment (JFAE) 5 (1) (2007) 8 - 11
4. Njenga, L. W. and Kariuki, D. N. “Determination of labile fluoride in Kenyan soils”. East
African Journal of Physical Science 6 (2) (2005) 57-66.
5. Njenga, L. W. Kariuki, D. N. and Ndegwa, S. “Water Labile fluoride from Fresh Raw
Vegetable Juices from Markets in Nairobi, Kenya”. Fluoride 38 (3) (2005) 205 – 208
6. Njenga, L. W. and Kariuki, D. N.: “Analysis of fluoride in locally available beverages:
Comparison of Direct, Oven Diffusion and Hexamethyldisiloxane Diffusion method”.
International Journal of BioChemiPhysics, 13 (2004) 26 – 31
7. R. W. Kahama, D. N. Kariuki and L. W. Njenga: “Effects of interfering ions on
hexamethyldisiloxane microdiffusion method”. Talanta 44 (1997) 1729-1733.15
8. R. W. Kahama, D. N. Kariuki, H. N. Kariuki and L. W. Njenga: “Fluorosis in children and
sources of fluoride around Lake Elementaita”. Fluoride 30 (1997) 19-25.
9. R. W. Kahama, D. N. Kariuki and L. W. Njenga: “Comparison of two microdiffusion
methods used to measure ionizable fluoride in cow milk. Analyst Vol. 120 (1995) 2245-
2247.L. W. Njenga,
10. L. W. Njenga “Determination of labile fluoride in soils: An Intercomparison of Different
Extracting Medias”. International Journal of BioChemiPhysics, 3, (1994) 18 – 22.
11. L. W. Njenga and D. N. Kariuki: “Accumulation of fluoride in plants and vegetables”.
International Journal of BioChemiPhysics, 3, (1994) 23 - 25.
12. L. W. Njenga, “Fluoride content in some Kenyan tea leaves” International Journal of
BioChemiPhysics, 3, (1994) 75 - 76.
13. L. W. Njenga: “Methods for Fluoride analysis in plants, foods and soil using fluoride ion
selective electrode”. Ph D. Thesis (1989), University of Nairobi.
14. L . Gustafsson and L. W. Njenga, “Determination of total fluoride in vegetables and plants
by open-flame ashing and microdiffusion: comparison with furnace ashing and oxygen-flask
combustion”. Analytical Chemical Acta 212 (1988) 133-143
15. D. N. Kariuki, H. M. Thairu, L. W. Njenga: (1984) “Dietary sources of fluoride in Kenya”.
Paper published in the proceedings of the workshop on “Fluorosis Research Strategies.
Published in African Medical and Research Foundation 36 [1984] 32 - 6.
16. L. W. Njenga “Determination of Fluoride in Water and Tea Using Ion Selective Electrode
and Calorimetric Methods”. MSc. Thesis (1982), University of Nairobi:
 BOOK PUBLICATION
Njenga L. W., Module II book for open distance learning book, title “Coordination chemistry”
Reviewed by Prof Shem O. Wandiga (Professor of Chemistry) and edited by Mr J. O.
Odumbe (Director CO&DL) [2005]
Njenga L. W., e-learning module II contents for “Coordination Chemistry”. 3rd year BED
(Science) course material. [2007]
Njenga L. W., Module II book for open distance learning book, title “Transition Elements and
Organometallic Chemistry” Reviewed by Prof Shem Wandiga (Professor in
Chemistry) [2009].





Everyone can afford an avocado, and many pick one up and have it cut into quarters, for immediate consumption as they walk on. Nairobi street food is good!




















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Ronaldo Aloise Pilli

Ronaldo Aloise Pilli

Formação Acadêmica

MS-6, Professor Titular; Bel. Instituto de Quimica, UNICAMP (1976), Dr. Sc. (UNICAMP, 1982); Pós-doutorado (University of California, Berkeley,1982-84); Professor Titular (UNICAMP, 2002)

Contato

Instituto de Química
Caixa Postal 6154
Campinas, SP
13083-862 Sala D-353
Fax 55 19 3521 3023
Fone 55 19 3521-3422
pilli@iqm.unicamp.br
Currículo Lattes

Pesquisa

- Síntese Orgânica
- Síntese de Produtos Naturais
- Síntese Assimétrica de Fármacos
- Estudos de Estrutura x Atividade Biológica
 

Publicação

1. PILLI, R. A. ; Ângelo de Fátima ; Luciana Konecny Kohn ; CARVALHO, J. E. . Cytotoxic Activity of (S)-goniothalamin and Analogues Against Human Cancer Cells. Bioorganic & Medicinal Chemistry, Estados Unidos, v. 14, p. 622-631, 2006.
2. PILLI, R. A. ; Andrea Leal de Sousa . A concise route to the azaspirodecane moiety of halichlorine and structurally related alkaloids. Organic Letters, Washington, DC, v. 7, p. 1617-1619, 2005.
3. PILLI, R. A. ; MALDANER, A. O. ; CORREA JR., I. R. ; ROSSO, G. B. . Total Synthesis and Structural Elucidation of Natural Products: (-)-Delactonmycin, (+)-Plumerinine and (-)-Parvistemoamide . Pure and Applied Chemistry, Grã-Bretanha, v. 77, p. 1153-1160, 2005.
4. PILLI, R. A. ; SANTOS, L. S. ; RAWAL, V. . Enantioselective Total Syntheses of (+)-Arborescidine A, (-)-Arborescidine B, and (-)-Arborescidine C. Journal of Organic Chemistry, Washington, DC, v. 69, p. 1283-1288, 2004.
5. PILLI, R. A. ; CORREA JR., I. R. . Total Synthesis and Structural Elucidation of (-)-Delactonmycin. Angewandte Chemie, Alemanha, v. 42, p. 3017-3020, 2003.

  
Pesquisadores do Departamento de Química Orgânica do Instituto de Química (IQ) da Unicamp sintetizaram uma substância que combate células cancerígenas de ...

 (+)-sitophilure

IUPAC Name: (4S,5R)-5-hydroxy-4-methylheptan-3-one | CAS Registry Number: 71699-35-9
Synonyms: Sitophilure, CID155663, 3-Heptanone, 5-hydroxy-4-methyl-, (R*,S*)-, 71699-35-9 

(+)-(4S,5R)-5-Hydroxy-4-methyl-3-pentanone (1)

To a solution of oxalyl chloride (0.013 mL, 0.15 mmol) in CH₂Cl₂ (1.0 mL) at -78 °C was added dimethyl sulfoxide (0.020 mL, 0.31 mmol) dropwise. The solution was stirred 10 min at -78 °C and a solution of a mixture of 11 and 12 (0.023 g, 0.089 mmol) in CH₂Cl₂ (1.0 mL) was added. The mixture was stirred 1.5 h at -78 °C, and treated with triethylamine (0.06 mL, 0.46 mmol). After warming to room temperature, the reaction was quenched with water, the layers were separated and the aqueous layer was extracted with CH₂Cl₂ (3 x 2 mL). The combined organic phases were washed with brine (4 mL), dried over MgSO₄ and concentrated under reduced pressure. The residue (0.019 g) was dissolved in THF (1 mL) at room temperature and treated with 1.0 M solution of TBAF (0.1 mL, 0.1 mmol) in THF. The mixture was stirred 1 day at room temperature, diluted with Et₂O (10 mL) and treated with aq. NH₄Cl (3 mL). The layers were separated and the aqueous layer was extracted with Et₂O (3 x 4 mL). The combined organic layers were dried over MgSO₄ and concentrated. Silica gel chromatography (30% AcOEt in hexanes, v/v) afforded (+)-1 (0.0074 g, 0.052 mmol) in 60% yield, as a colorless oil.

 ¹H-NMR (CDCl₃, 300 MHz): d 0.96 (t, 3H, J = 7 Hz); 1.06 (t, 3H, J = 7 Hz); 1.14 (d, 3H, J = 7 Hz); 1.37 (ddq, 1H, J = 15, 7 and 3 Hz); 1.51 (ddq, 1H, J = 15, 8 and 7 Hz); 2.42-2.70 (m, 3H); 2.86 (br s, 1H); 3.83 (ddd, 1H, J = 8, 5 and 3 Hz). 

¹³C-NMR (CDCl₃, 75.5 MHz): d 7.6; 9.9; 10.4; 26.8; 35.1; 49.3; 72.6; 216.8.

 IR (film): 3453; 1701; 1460 cm^-1. [a]_D +24.8 (c1.24, Et₂O). lit.²: [a]_D +27.0 (c1.24, Et₂O).

J. Braz. Chem. Soc. vol.10 no.5 São Paulo Sept./Oct. 1999

http://dx.doi.org/10.1590/S0103-50531999000500005 

Article

The Asymmetric Synthesis of (+)-Sitophilure, the Natural Form of the Aggregation Pheromone of Sitophilus oryzae L. and Sitophilus zeamais M.

Ronaldo A. Pilli*, and Valéria B. Riatto

Instituto de Química, UNICAMP, C.P. 6154, 13083-970 Campinas - SP Brazil

http://www.scielo.br/scielo.php?pid=S0103-50531999000500005&script=sci_arttext

*e-mail: pilli@iqm.unicamp.br  and vbriatto@iqm.unicamp.br

MORE FROM OTHER AUTHORS


http://www.google.com/patents/US20090298147............


In 1984, Burkholder and coworkers isolated the male-produced aggregation pheromone of the pests rice weevil (Sitophilus oryzae L.) and maize weevil (Sitophilus zeamais M.), which is named Sitophilure.^[8] This biologically-active compound was first identified as (4R,5S)-5-hydroxy-4-methyl-3-heptanone, from the extracts of thousands of insects. All four stereoisomers of this pheromone were synthesized and it was proved that the active form of this compound is the (4S,5R) enantiomer.^[9] Since then, several total syntheses of racemic,^[10] or other stereoisomers^[11] and the natural form^[12] of this pheromone have been published.
Serious economic losses of stored cereal grains (maize, rice and grain) are mainly caused by three weevils of the genus Sitophilus(Sitophilus zeamais, Sitophilus oryzae, Sitophilus granarius respectively) throughout the world. Early detection of infestations is critical in order to avoid further damage to the grains and the subsequent economic losses. Traps that contain very small amounts of synthetic (+)-sitophilure have been shown to be very effective in the early detection of all three species of weevils,^[13]however a simple scalable and economic method for the synthesis of this weevil attractant pheromone is still lacking.^[9-12] As a result, all of the commercially available traps for the early detection of these weevils are food-based.


The absolute stereochemistry of the enantiomers B and D (Scheme 3) was found to be (4S,5R) and (4S,5S) respectively, taking into account that the relative stereochemistry of the product D is anti and of the product B syn. 

As we can see in Scheme 3, the product from the reduction of 4-methyl-3,5-heptanedione with KRED-A1C has the same stereochemistry with that of the natural pheromone (+)-Sitophilure. These results clearly indicate that ketoreductases KRED-A1B, KRED-A1C and KRED-A1D showed unusual anti-Prelog selectivity, concerning reduction of the 5-keto group and successfully produced the keto alcohol with the desired stereochemistry 4S,5R. So the natural product can be produced easily from the corresponding diketone.
In large scale, the reaction is completed in 24 hours, producing the pheromone with chemical yield 85%, de 96%, ee >99%, and chemical purity >99%, utilizing catalytic amounts of the NADPH cofactor (0.81% relative to the substrate), which was recycled in situ using Glucose Dehydrogenase (GDH). The corresponding 4-methyl-3,5-heptanedione can be readily produced from the commercially available 3,5-heptanedione (Scheme 4).

Synthesis of (4S,5R)-5-hydroxy-4-methyl-3-heptanone
A phosphate-buffered solution (16 mL, pH 6.5, 200 mM) containing 84 mM (1.35 mmol, 192 mg) of 4-methyl-3,5-heptanedione, NaCl (200 mM, 200 mg), glucose (130 mM, 375 mg), NADPH (0.69 mM, 0.011 mmol, 10 mg), glucose dehydrogenase (10 mg) and KRED-A1C (10 mg) was stirred at 25° C. for 24 hours, until GC analysis of crude extracts showed complete reaction. Periodically the pH was readjusted to 6.5 with NaOH (2 M). The product was isolated by extracting the crude reaction mixture with EtOAc (15 mL×2). The combined organic layers were then extracted with saturated NaCl solution, dried over MgSO₄ and evaporated to dryness. Pure (4S,5R)-5-hydroxy-4-methyl-3-heptanone (165 mg) was obtained in 85% yield. ¹H NMR (CDCl₃ 500 MHz, δ ppm):¹H NMR (CDCl₃ 500 MHz, δ ppm): 3.77-3.85 (m, 1H), 2.72 (s, OH), 2.41-2.64 (m, 3H), 1.32-1.58 (m, 2H), 1.12 (d, J=7.1 Hz, 3H), 1.05 (t, J=7.3 Hz, 3H), 0.95 (t, J=7.4 Hz, 3H). ¹³C NMR (CDCl₃ 300 MHz, δ ppm): 216.7, 72.6, 49.3, 35.1, 26.9, 10.4, 9.9, 7.6.
Determination of the Enantiomeric Purity of (4S,5R)-5-hydroxy-4-methyl-3-heptanone: GC (column: 30 m×0.25 mm×0.25 μm chiral capillary column, 20% permethylated cyclodextrin 65° C. for 100 min, rate: 1° C./min, final temp.: 100° C.; carrier gas: N₂, press 70 kPa). t_R=100.0 min [98%, (4S,5R)-5-hydroxy-4-methyl-3-heptanone], t_R=105.1 min [2%, (4R,5R)-5-hydroxy-4-methyl-3-heptanone]. The enantiomeric purity was estimated to be >99% and the diastereomeric purity 96%.

Administração e Biblioteca do Instituto de Química da UNICAMP, Campinas.

Instituto de Química - Unicamp

Lab. de Ensino, Biblioteca e Administração

Campinas
Municipality
The Municipality of Campinas
Images from top, left to right: Metropolitan Cathedral, an avenue in Campinas's downtown,an old railway station, Mogiana Palace, a monument to the heroes of Constitutionalist Revolution (in Saudade Cemetery), a bus terminus, Central area of Campinas as seen fromTorre do Castelo, a belvedere.
Flag Seal
Nickname(s): Cidade das Andorinhas, Brazilian Silicon Valley, Princesa d'Oeste
Location of Campinas
Campinas Location in Brazil
Coordinates: 22°54′3″S 47°03′26″W
Country	Brazil
Region	Southeast
State	São Paulo
Founded	July 14, 1774
Government
• Mayor	Jonas Donizette (PSB)
Area
• Municipality	795.667 km2 (307.209 sq mi)
• Metro	3,645 km2 (1,407 sq mi)
Elevation	555-780 m (1,821–2,559 ft)
Population (2012)
• Municipality	1,098,630 (14th)
• Density	1,358.6/km2 (3,519/sq mi)
• Metro	2,633,523
Time zone	Brasilia Official Time (UTC-3)
• Summer (DST)	Brazilian Daylight Saving Time(UTC-2)
Postal Code	13000-000
Area code(s)	+55 19
Website	Campinas, São Paulo

History

Campinas in 1878

Maps of railways in Campinas in 1929

Regatas Club in Cambuí neighborhood.

   Instituto de Química

1. • 
2. 

 

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Brazil's favourite street food is acaraje, black-eyed pea fritters which are often stuffed with shrimps. Brought to Brazil by West African slaves, ...











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