ChemInform Abstract: Diterpenes from the Leaf Exudate of Psiadia punctulata.

ChemInform ◽  
2010 ◽  
Vol 28 (28) ◽  
pp. no-no
Author(s):  
J. O. MIDIWO ◽  
F. A. O. OWUOR ◽  
B. F. JUMA ◽  
P. G. WATERMAN
Keyword(s):  
1991 ◽  
Vol 46 (3-4) ◽  
pp. 177-182 ◽  
Author(s):  
Hans-W. Rauwald ◽  
Deo-D. Niyonzima

From the leaf exudate of Aloe lateritia ENGLER the C-glucosyl com pounds homonataloin, aloeresin A and aloesin (synon. aloeresin B) were isolated together with the anthraquinone nataloeem odin-8-methylether and spectroscopically identified. Hom onataloin, widely distributed in Aloe species, was separated into homonataloin A and B by combined TLC and DCCC. In their 1 D and 2D 1H NMR spectra only the shifts of the 2′-hydroxyl protons of both glucosyl residues differ significantly, indicative of 10 S (A) resp. 10 S (B) configurations. In both com pounds the anthrone is in β-position of the D-glucopyranosyl, as determined by the large coupling constants of the anomeric protons. The 13C NMR signals are unambiguously assigned by the use of DEPT, APT and gated-decoupling methods. Only the chemical shifts of C -11 and C -14 show significant differences between both diastereomers due to the adjacent 2′-sugar hydroxyls. The two homonataloins differ mostly in optical rotation and circulardichroism due to different configurations at C - 10 of the anthrone part. The absolute configurations of the diastereomers are determined by correlation of their CD spectra with the CD spectra of the structural analogues 7-hydroxyaloins A and B, which shows that hom onataloin A is the 10 S, 1′S-compound and that homonataloin B has 10 R, 1′S-configuration.


2010 ◽  
Vol 3 (4) ◽  
pp. 217-220 ◽  
Author(s):  
Leonidah K. Omosa ◽  
Jacob O. Midiwo ◽  
Solomon Derese ◽  
Abiy Yenesew ◽  
Martin G. Peter ◽  
...  

2006 ◽  
Vol 24 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Avijit Dutta ◽  
Goutam Mandal ◽  
Chitra Mandal ◽  
Mitali Chatterjee

1989 ◽  
Vol 15 (4) ◽  
pp. 1203-1217 ◽  
Author(s):  
Joseph Huesing ◽  
Davy Jones ◽  
Joseph Deverna ◽  
Jim Myers ◽  
Glenn Collins ◽  
...  

2007 ◽  
Vol 2 (3) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Jaromir Budzianowski ◽  
Eckhard Wollenweber

5,6,2′,3′,6′-Pentamethoxyflavone (1), together with 3′,5′-dihydroxy-4′-methoxyflavone (2), 2′-methoxyflavone, 3′-methoxyflavone, 3′,4′-dimethoxyflavone, 2′,5′-methoxyflavone, 3′-hydroxy-4′,5′-dimethoxyflavone, 3′,4′,5′-trimethoxyflavone, and 3′-hydroxy-4′,5′-methylenedioxyflavone were found in the leaf exudate of the oxlip, Primula elatior (Primulaceae). The structures of flavones 1 and 2 were substantiated by 2D NMR spectroscopy.


1989 ◽  
Vol 44 (9-10) ◽  
pp. 727-730 ◽  
Author(s):  
E. Wollenweber ◽  
F. J. Arriaga-Giner ◽  
A. Rumbero ◽  
W. Greenaway

Several lipophilic phenolics were found in leaf resins of Baccharis species, reported earlier to produce terpenoids and flavonoid aglycones. They were identified by NMR and GC/MS studies, respectively. The structure of 2′,4′β-trihydroxy-6′-methoxychalcone from B. salicifolia was confirmed by synthesis. Phenylethyl caffeate and benzyl caffeate were found in B. sarothroides.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Demoze Asmerom ◽  
Tesfay Haile Kalay ◽  
Gebrehiwot Gebremedhin Tafere

Infectious diseases caused by fungi and bacteria are among the major causes of illness and death worldwide. This is mainly implicated by the antimicrobial resistance of the current treatment regimens. Since plant products are house stores of bioactive compounds, it is essential to screen plant-based antimicrobials to come up with novel medicines that counter the grave consequences of antimicrobial resistance. In the folk medicine of Ethiopia, Aloe megalacantha is used for the treatment of wound, dandruff, malaria, diabetes, impotence, colon cleansing, amoeba, ascariasis, abdominal pain, urine retention, snake bite, and evil eye. Hence, the present study was aimed to evaluate the antibacterial and antifungal effects of the leaf exudate of Aloe megalacantha. Agar well diffusion was employed to determine the antibacterial and antifungal effects. Six bacterial strains, namely, S. aureus (standard), S. aureus (clinical isolate), E. coli ATCC 25922 (standard), E. coli (clinical isolate), K. pneumoniae (standard), and P. aeruginosa ATCC 27853 (standard), and four fungal strains such as C. albicans, C. glabrata, C. tropicalis, and C. krusei were studied. The leaf exudate showed the highest activity against C. krusei with an average zone diameter of 22.49 ± 0.47 mm at 400 mg/mL. Among the bacterial species, S. aureus ATCC 29213 (standard) was the most sensitive with an average zone of diameter of 16.63 ± 0.12 mm at 200 mg/mL. Thus, the present findings support the folklore use of Aloe megalacantha for the treatment of different microbial infections.


1971 ◽  
Vol 49 (2) ◽  
pp. 181-185 ◽  
Author(s):  
R. Hall ◽  
L. V. Busch

The vascular system of leaves of chrysanthemum plants inoculated with Verticillium dahliae was invaded by mycelium before the appearance of visible wilt symptoms. After flower buds appeared a rapid rise in the number of propagules of fungus in the leaf was followed by a rise in severity of visible wilt symptom expression and conductivity of leaf exudate. Those portions of the leaf with the most advanced stages of wilt contained the greatest amounts of fungus. It is suggested that the mycelium within the leaf makes a significant contribution to the development of symptoms of wilt.


Sign in / Sign up

Export Citation Format

Share Document