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1

Antimicrobial acylphloroglucinols and dibenzyloxy flavonoids from flowers of Helichrysum gymnocomum

Siegfried E. Drewes, Sandy F. van Vuuren

Journal:

Year:

2008

Language:

english

File:

PDF, 194 KB

english, 2008

2

Vasodilatory and hypoglycaemic effects of two pyrano-isoflavone extractives from Eriosema kraussianum N. E. Br. [Fabaceae] rootstock in experimental rat models

John A.O. Ojewole, Siegfried E. Drewes, Fatima Khan

Journal:

Year:

2006

Language:

english

File:

PDF, 159 KB

english, 2006

3

Synthesis, resolution and assignment of absolute configuration of 2-(α-hydroxy)aryl acrylate esters

Siegfried E. Drewes, Neville D. Emslie, John S. Field, Abdullah A. Khan, Niyum Ramesar

Journal:

Tetrahedron: Asymmetry

Year:

1992

Language:

english

File:

PDF, 308 KB

english, 1992

4

Total Synthesis of the Pyranoisoflavone Kraussianone 1 and Related Isoflavones

Selepe, Mamoalosi A., Drewes, Siegfried E., van Heerden, Fanie R.

Journal:

Journal of Natural Products

Year:

2010

Language:

english

File:

PDF, 219 KB

english, 2010

5

Iridoid Molluscicidal Compounds from Apodytes dimidiata

Drewes, Siegfried E., Kayonga, Louis, Clark, Tanza E., Brackenbury, Therese D., Appleton, Christopher C.

Journal:

Journal of Natural Products

Year:

1996

Language:

english

File:

PDF, 71 KB

english, 1996

6

Facile Diastereoselective Synthesis of 2,6-Dialkyl-5-methylene-1,3-dioxan-4-ones via α-Activated Vinyl Esters

Siegfried E. Drewes, Neville D. Emslie, Nazira Karodia, Abdullah A. Khan

Journal:

European Journal of Inorganic Chemistry

Year:

1990

Language:

english

File:

PDF, 174 KB

english, 1990

7

Cyclization of a chiral α-(δ′-benzyloxyalkyl)acrylate to a novel tetrahydrofuran derivative

Siegfried E. Drewes, Owen L. Njamela, Gregory H. P. Roos

Journal:

European Journal of Inorganic Chemistry

Year:

1990

Language:

english

File:

PDF, 176 KB

english, 1990

8

Crystalline, Enantiomerically Pure Aldols from a (-)-Ephedrine-Derived N-Acylimidazolidin-2-one

Siegfried E. Drewes, Dean G. S. Malissar, Gregory H. P. Roos

Journal:

European Journal of Inorganic Chemistry

Year:

1991

Language:

english

File:

PDF, 199 KB

english, 1991

9

(R)1-(+)1-Pantolactone Acrylate as a Chiral Auxiliary in the Baylis-Hillman Reaction

Abdullah A. Khan, Neville D. Emslie, Siegfried E. Drewes, John S. Field, Niyum Ramesar

Journal:

European Journal of Inorganic Chemistry

Year:

1993

Language:

english

File:

PDF, 453 KB

english, 1993

10

Ephedrine-Derived Imidazolidin-2-ones. Broad Utility Chiral Auxiliaries in Asymmetric Synthesis

Siegfried E. Drewes, Dean G. S. Malissar, Gregory H. P. Roos

Journal:

European Journal of Inorganic Chemistry

Year:

1993

Language:

english

File:

PDF, 1.15 MB

english, 1993

11

ChemInform Abstract: Alkaloids from Crinum bulbispermum.

Esameldin E. Elgorashi, Siegfried E. Drewes, Johannes Van Staden

Journal:

Year:

2000

File:

PDF, 23 KB

2000

12

ChemInform Abstract: An Acylated Phloroglucinol with Antimicrobial Properties from Helichrysum caespititium.

Abbey D. M. Mathekga, J. J. Marion Meyer, Marion M. Horn, Siegfried E. Drewes

Journal:

Year:

2000

File:

PDF, 28 KB

2000

13

ChemInform Abstract: Reaction of 2-Formyl Imidazole with Intermediates from the Baylis—Hillman Reaction.

Siegfried E. Drewes, Marion M. Horn, Niyum Ramesar

Journal:

Year:

2000

File:

PDF, 27 KB

2000

14

Zur weiteren Kenntnis des Chlorophylls und des Hämins, XXII. „M + 2”-Peaks. Hydrierung von Doppelbindungen im Massenspektrometer

Herbert Budzikiewicz, Siegfried E. Drewes

Journal:

European Journal of Organic Chemistry

Year:

1968

Language:

german

File:

PDF, 111 KB

german, 1968

15

Synthesis of rooperol [1,5-bis(3′,4′-dihydroxyphenyl)pent-1-en-4-yne]

Maudene Potgieter, George L. Wenteler, Siegfried E. Drewes

Journal:

Year:

1988

Language:

english

File:

PDF, 317 KB

english, 1988

16

Structure determination of a phenolic pent-1-en-4-yne derivative from Hypoxis rooperi

Siegfried E. Drewes, Ursula J. Scogings, George L. Wenteler

Journal:

Year:

1989

Language:

english

File:

PDF, 313 KB

english, 1989

17

A geraniol glycoside from Hypoxis acuminata

Martin W. Bredenkamp, Siegfried E. Drewes, George L. Wentler

Journal:

Year:

1989

Language:

english

File:

PDF, 303 KB

english, 1989

18

11,11-dimethyl-1,3,8,10-tetrahydroxy-9-methoxypeltogynan and three pentacyclic triterpenes from Cassine transvaalensis

Siegfried E. Drewes, M.Jeffrey Mashimbye, John S. Field, Niyum Ramesar

Journal:

Year:

1991

Language:

english

File:

PDF, 703 KB

english, 1991

19

(+)-Afzelechin 3-rhamnoside from Cassipourea gerrardii

Siegfried E. Drewes, Craig W. Taylor, Anthony B. Cunningham

Journal:

Year:

1992

Language:

english

File:

PDF, 322 KB

english, 1992

20

Epiafzelechin-(4β→8, 2β→0→7)-ent-afzelechin from Cassipourea gerrardii

Anthony B. Cunningham, Daneel Ferreira, Jacobus A. Steenkamp, C.Hendrick L. Mouton, Siegfried E. Drewes, Craig W. Taylor

Journal:

Year:

1992

Language:

english

File:

PDF, 319 KB

english, 1992

21

Flavanoids and triterpenoids from Cassine papillosa and the absolute configuration of 11,11-dimethyl-1,3,8,10-tetra-hydroxy-9-methoxypeltogynan

Siegfried E. Drewes, M.Jeffrey Mashimbye

Journal:

Year:

1993

Language:

english

File:

PDF, 355 KB

english, 1993

22

Iso-ocobullenone and a neolignan ketone from ocotea bullata bark

Siegfried E. Drewes, Marion M. Horn, Bethuel M. Sehlapelo, Nyum Ramesar, John S. Field, Scott Shaw, Peter Sandor

Journal:

Year:

1995

Language:

english

File:

PDF, 262 KB

english, 1995

23

5,6-dihydro-α-pyrones and two bicyclic tetrahydro-α-pyrone derivatives from Cryptocarya latifolia

Siegfried E. Drewes, Bethuel M. Sehlapelo, Marion M. Horn, Robert Scott-Shaw, Peter Sandor

Journal:

Year:

1995

Language:

english

File:

PDF, 275 KB

english, 1995

24

Methylated a-type proanthocyanidins and related metabolites from Cassipourea gummiflua

Siegfried E. Drewes, Craig W. Taylor

Journal:

Year:

1994

Language:

english

File:

PDF, 393 KB

english, 1994

25

α-Pyrones and their derivatives from two Cryptocarya species

Siegfried E. Drewes, Marion M. Horn, Robert Scott Shaw

Journal:

Year:

1995

Language:

english

File:

PDF, 221 KB

english, 1995

26

Anti-inflammatory activity and QSAR studies of compounds isolated from Hyacinthaceae species and Tachiadenus longiflorus Griseb. (Gentianaceae)

Karen du Toit, Esameldin E. Elgorashi, Sarel F. Malan, Siegfried E. Drewes, Johannes van Staden, Neil R. Crouch, Dulcie A. Mulholland

Journal:

Bioorganic & Medicinal Chemistry

Year:

2005

Language:

english

File:

PDF, 158 KB

english, 2005

27

Global phytochemistry: indigenous medicinal chemistry on track in southern Africa

Dulcie A. Mulholland, Siegfried E. Drewes

Journal:

Year:

2004

Language:

english

File:

PDF, 627 KB

english, 2004

28

Minor pyrano-isoflavones from Eriosema kraussianum: activity-, structure-, and chemical reaction studies

Siegfried E. Drewes, Marion M. Horn, Fatima Khan, Orde Q. Munro, Jabu T.B. Dhlamini, Christopher Rakuambo, J.J. Marion Meyer

Journal:

Year:

2004

Language:

english

File:

PDF, 257 KB

english, 2004

29

Simple 1,4-benzoquinones with antibacterial activity from stems and leaves of Gunnera perpensa

Siegfried E. Drewes, Fatima Khan, Sandy F. van Vuuren, Alvaro M. Viljoen

Journal:

Year:

2005

Language:

english

File:

PDF, 116 KB

english, 2005

30

Antimicrobial monomeric and dimeric diterpenes from the leaves of Helichrysum tenax var tenax

Siegfried E. Drewes, K. Esther Mudau, Sandy F. van Vuuren, Alvaro M. Viljoen

Journal:

Year:

2006

Language:

english

File:

PDF, 309 KB

english, 2006

31

Bufadienolides from bulbs of Urginea lydenburgensis (Hyacinthaceae: Urgineoideae)

Neil R. Crouch, Karen du Toit, Dulcie A. Mulholland, Siegfried E. Drewes

Journal:

Year:

2006

Language:

english

File:

PDF, 128 KB

english, 2006

32

Stereostructure and anti-inflammatory activity of three diastereomers of ocobullenone from Ocotea bullata

Sibylle Zschocke, Johannes van Staden, Kerstin Paulus, Rudolf Bauer, Marion M. Horn, Orde Q. Munro, Nicola J. Brown, Siegfried E. Drewes

Journal:

Year:

2000

Language:

english

File:

PDF, 268 KB

english, 2000

33

Alkaloids from Crinum moorei

Esameldin E. Elgorashi, Siegfried E. Drewes, Johannes van Staden

Journal:

Year:

2001

Language:

english

File:

PDF, 105 KB

english, 2001

34

Transformation of naturally-occurring 1,9-trans-9,5-cis sweroside to all trans sweroside during acetylation of sweroside aglycone

Marion M. Horn, Siegfried E. Drewes, Nicola J. Brown, Orde Q. Munro, J.J.Marion Meyer, Abbey D.M. Mathekga

Journal:

Year:

2001

Language:

english

File:

PDF, 197 KB

english, 2001

35

Isolation of hypoxoside from hypoxis rooperi and synthesis of (E)-1,5-bis(3′,4′-dimethoxyphenyl)pent-4-en-1-yne

Siegfried E. Drewes, Alida J. Hall, Robin A. Learmonth, Ursula J. Upfold

Journal:

Year:

1984

Language:

english

File:

PDF, 303 KB

english, 1984

36

A 6-substituted 5,6-dihydro-α-pyrone from two species of Cryptocarya

Bethuel M. Sehlapelo, Siegfried E. Drewes, Robert Scott-Shaw

Journal:

Year:

1994

Language:

english

File:

PDF, 239 KB

english, 1994

37

Ocobullenone: A bicyclo[3.2.1]octanoid neolignan from Ocotea bullata

Bethuel M. Sehlapelo, Siegfried E Drewes, Peter Sandor

Journal:

Year:

1993

Language:

english

File:

PDF, 253 KB

english, 1993

38

Exocarpic acid and other compounds from tubers and inflorescences of Sarcophyte sanguinea

Lovina A.C. Naidoo Siegfried E.^Drewes, J.Van Staden, Anne Hutchings

Journal:

Year:

1992

Language:

english

File:

PDF, 298 KB

english, 1992

39

Brackenin, a dimeric dihydrochalcone from Brackenridgea zanguebarica

Siegfried E. Drewes, Neale A. Hudson

Journal:

Year:

1983

Language:

english

File:

PDF, 336 KB

english, 1983

40

Pyrano-isoflavones with erectile-dysfunction activity from Eriosema kraussianum

Siegfried E. Drewes, Marion M. Horn, Orde Q. Munro, Jabu T.B. Dhlamini, J.J.Marion Meyer, N.Christopher Rakuambo

Journal:

Year:

2002

Language:

english

File:

PDF, 225 KB

english, 2002

41

Recent findings on natural products with erectile-dysfunction activity

Siegfried E Drewes, Jacob George, Fatima Khan

Journal:

Year:

2003

Language:

english

File:

PDF, 232 KB

english, 2003

42

6-(2, 3, 4-Trihydroxy-3-methylbutylamino)purine, a cytokinin with high biological activity

Johannes van Staden, Siegfried E. Drewes

Journal:

Year:

1982

Language:

english

File:

PDF, 167 KB

english, 1982

43

Absolute configuration of α-pyrones from Cryptocarya latifolia and Syncolostemon densiflorus

Lynne A. Collett, Michael T. Davies-Coleman, Douglas E.A. Rivett, Siegfried E. Drewes, Marion M. Horn

Journal:

Year:

1997

Language:

english

File:

PDF, 262 KB

english, 1997

44

Absolute configurations of all four stereoisomers of cryptocaryalactone and deacetyl cryptocaryalactone

Siegfried E Drewes, Marion M Horn, Niyum S Ramesar, Daneel Ferreira, Reinier J.J Nel, Anne Hutchings

Journal:

Year:

1998

Language:

english

File:

PDF, 254 KB

english, 1998

45

Stereostructure, conformation and reactivity of P- and a-gardiol from Burchellia bubalina

Siegfried E Drewes, Marion M Horn, Orde Q Munro, Niyum Ramesar, Michael Ochse, Gerhard Bringmann, Karl Peters, Eva-Maria Peters

Journal:

Year:

1999

Language:

english

File:

PDF, 639 KB

english, 1999

46

A drimane sesquiterpenoid lactone from Warburgia salutaris

Mahlori J Mashimbye, Munaka C Maumela, Siegfried E Drewes

Journal:

Year:

1999

Language:

english

File:

PDF, 103 KB

english, 1999

47

Enolic iridolactone and other iridoids from Alberta magna

Siegfried E. Drewes, Marion M. Horn, Joseph D. Connolly, Barry Bredenkamp

Journal:

Year:

1998

Language:

english

File:

PDF, 562 KB

english, 1998

48

Alkaloids from Crinum bulbispermum

Esameldin E Elgorashi, Siegfried.E Drewes, Johannes Van Staden

Journal:

Year:

1999

Language:

english

File:

PDF, 117 KB

english, 1999

49

An acylated phloroglucinol with antimicrobial properties from Helichrysum caespititium

Abbey D.M. Mathekga, J.J.Marion Meyer, Marion M. Horn, Siegfried E. Drewes

Journal:

Year:

2000

Language:

english

File:

PDF, 107 KB

english, 2000

50

Synthetic potential of the tertiary-amine-catalysed reaction of activated vinyl carbanions with aldehydes

Siegfried E. Drewes, Gregory H.P. Roos

Journal:

Year:

1988

Language:

english

File:

PDF, 1.38 MB

english, 1988