TY  - JOUR
A1  - Gumula, Ivan
A1  - Heydenreich, Matthias
A1  - Derese, Solomon
A1  - Ndiege, Isaiah O.
A1  - Yenesew, Abiy
T1  - Four isoflavanones from the stem bark of Platycelphium voense
JF  - Phytochemistry letters
N2  - From the stem bark of Platycelphium voense (Leguminosae) four new isoflavanones were isolated and characterized as (S)-5,7-dihydroxy-2 ',4 '-dimethoxy-3 '-(3 ''-methylbut-2 ''-enyl)-isoflavanone (trivial name platyisoflavanone A), (+)-5,7,2 '-trihydroxy-4 '-methoxy-3 '-(3 ''-methylbut-2 ''-enyl)-isoflavanone (platyisoflavanone B), 5,7-dihydroxy-4 '-methoxy-2 ''-(2 '''-hydroxyisopropyl)-dihydrofurano-[4 '',5 '':3 ',2 ']-isoflavanone (platyisoflavanone C) and 5,7,2 ',3 ''-tetrahydroxy-2 '',2 ''-dimethyldihydropyrano-[5 '',6 '':3 ',4 ']-isoflavanone (platyisoflavanone D). In addition, the known isoflavanones, sophoraisoflavanone A and glyasperin F; the isoflavone, formononetin; two flavones, kumatakenin and isokaempferide; as well as two triterpenes, betulin and beta-amyrin were identified. The structures were elucidated on the basis of spectroscopic evidence. Platyisoflavanone A showed antibacterial activity against Mycobacterium tuberculosis in the microplate alamar blue assay (MABA) with MIC = 23.7 mu M, but also showed cytotoxicity (IC50 = 21.1 mu M) in the vero cell test.
KW  - Platycelphium voense
KW  - Stem bark
KW  - Leguminosae
KW  - Isoflavanones
KW  - Platyisoflavanone
KW  - Mycobacterium tuberculosis
Y1  - 2012
U6  - https://doi.org/10.1016/j.phytol.2011.11.012
SN  - 1874-3900
VL  - 5
IS  - 1
SP  - 150
EP  - 154
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Induli, Martha
A1  - Cheloti, Michael
A1  - Wasuna, Antonina
A1  - Wekesa, Ingrid
A1  - Wanjohi, John M.
A1  - Byamukama, Robert
A1  - Heydenrich, Matthias
A1  - Makayoto, Moses
A1  - Yenesew, Abiy
T1  - Naphthoquinones from the roots of Aloe secundiflora
JF  - Phytochemistry letters
N2  - Two new naphthoquinones, 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione and 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione, were isolated from the roots of Aloe secundiflora together with the known compounds chrysophanol, helminthosporin, isoxanthorin, ancistroquinone C, aloesaponarins I and II, aloesaponols I and II, laccaic acid D methyl ester and asphodelin. The structures were elucidated based on spectroscopic evidence. This appears to be the first report on the occurrence of naphthoquinones in the genus Aloe. Aloesaponarin I and 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione showed anti-bacterial activity against Mycobacterium tuberculosis with MIC values of 21-23 mu g/mL in the Microplate Alamar Blue Assay (MABA) and Low Oxygen Recovery Assay (LORA); 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione also showed cytotoxicity against the Vero cell line (IC50 = 10.2 mu g/mL).
KW  - Aloe secundiflora
KW  - Asphodelaceae
KW  - Roots
KW  - Naphthoquinone
KW  - 5-Hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione 5,8-Dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione
KW  - Anthraquinone
KW  - Aloesaponarin I
KW  - Mycobacterium tuberculosis
Y1  - 2012
U6  - https://doi.org/10.1016/j.phytol.2012.04.014
SN  - 1874-3900
VL  - 5
IS  - 3
SP  - 506
EP  - 509
PB  - Elsevier
CY  - Amsterdam
ER  -