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New 14-membered cyclopeptide alkaloids from Zizyphus oxyphylla Edgew.

Kaleem WA, Nisar M, Qayum M, Zia-Ul-Haq M, Adhikari A, De Feo V - Int J Mol Sci (2012)

Bottom Line: Two new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew.The compounds were tested for antibacterial activity.Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 μg/mL) than other compounds.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, Abdul Wali Khan University Mardan, Anbar Campus 23200, Pakistan; E-Mail: waqar679@yahoo.co.uk.

ABSTRACT
Two new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew. The compounds were tested for antibacterial activity. Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 μg/mL) than other compounds. This compound also exhibited weak antimicrobial activities against Staphylococcus aureus (MIC, 25 μg/mL), Pseudomonas aeruginosa (MIC, 50 μg/mL) and Salmonella typhi (MIC, 50 μg/mL).

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Related in: MedlinePlus

(A) Key COSY and NOESY interactions in oxyphylline B (4); (B) Key HMBC interactions in oxyphylline B (4).
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f2-ijms-13-11520: (A) Key COSY and NOESY interactions in oxyphylline B (4); (B) Key HMBC interactions in oxyphylline B (4).

Mentions: 13C NMR (BB and DEPT) (Table 1) displayed resonances for 33 carbons, including four methyl, three methylene, 19 methine and seven quaternary carbons. The combined use of 1D (1H, and 13C) and 2D spectra (COSY and HSQC) revealed the different spin systems of the amino acid units such as isoleucine, proline and valine, as well as p-oxygenated Z-styrylamine and cinnamoyl moiety. For further verification, HMBC experiments were conducted. The HMBC connectivity of H-7 (δ 4.10) to C-5 (δ 172.1), C-8 (δ 168.1), C-17 (δ 37.1) and C-18 (δ 24.8) confirmed the presence of an isoleucine unit as a part of the cyclic ring. Similarly, H-3 (δ 5.80) exhibited the HMBC connectivities with C-21 (δ 32.8), C-4 (δ 65.4), C-1 (δ 158.7), and C-22 (δ 47.2), confirming the presence of a β-substituted proline unit. The correlations of H-10 (δ 6.10) with C-8 (δ 168.1), C-12 (δ 133.4) reconfirmed the presence of a styrylamine moiety. HMBC cross peaks for methine hydrogen H-25 (δ 4.50) to C-24 (δ 172.0), C-30 (δ 166.2), C-26 (δ 31.8) and C-27 (δ 19.4), revealed the fact that the valine amino acid unit has joined the proline amino acid unit and the cinnamoyl moiety. Furthermore, H-31 displayed HMBC correlations with C-30 (δ 166.2) and C-33 (δ 136.3), reconfirming the previous hypothesis. The stereochemistry of the compound was assigned on the basis of coupling constants and NOESY experiments. Key NOESY interactions in compound 4 are shown in Figure 2.


New 14-membered cyclopeptide alkaloids from Zizyphus oxyphylla Edgew.

Kaleem WA, Nisar M, Qayum M, Zia-Ul-Haq M, Adhikari A, De Feo V - Int J Mol Sci (2012)

(A) Key COSY and NOESY interactions in oxyphylline B (4); (B) Key HMBC interactions in oxyphylline B (4).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472760&req=5

f2-ijms-13-11520: (A) Key COSY and NOESY interactions in oxyphylline B (4); (B) Key HMBC interactions in oxyphylline B (4).
Mentions: 13C NMR (BB and DEPT) (Table 1) displayed resonances for 33 carbons, including four methyl, three methylene, 19 methine and seven quaternary carbons. The combined use of 1D (1H, and 13C) and 2D spectra (COSY and HSQC) revealed the different spin systems of the amino acid units such as isoleucine, proline and valine, as well as p-oxygenated Z-styrylamine and cinnamoyl moiety. For further verification, HMBC experiments were conducted. The HMBC connectivity of H-7 (δ 4.10) to C-5 (δ 172.1), C-8 (δ 168.1), C-17 (δ 37.1) and C-18 (δ 24.8) confirmed the presence of an isoleucine unit as a part of the cyclic ring. Similarly, H-3 (δ 5.80) exhibited the HMBC connectivities with C-21 (δ 32.8), C-4 (δ 65.4), C-1 (δ 158.7), and C-22 (δ 47.2), confirming the presence of a β-substituted proline unit. The correlations of H-10 (δ 6.10) with C-8 (δ 168.1), C-12 (δ 133.4) reconfirmed the presence of a styrylamine moiety. HMBC cross peaks for methine hydrogen H-25 (δ 4.50) to C-24 (δ 172.0), C-30 (δ 166.2), C-26 (δ 31.8) and C-27 (δ 19.4), revealed the fact that the valine amino acid unit has joined the proline amino acid unit and the cinnamoyl moiety. Furthermore, H-31 displayed HMBC correlations with C-30 (δ 166.2) and C-33 (δ 136.3), reconfirming the previous hypothesis. The stereochemistry of the compound was assigned on the basis of coupling constants and NOESY experiments. Key NOESY interactions in compound 4 are shown in Figure 2.

Bottom Line: Two new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew.The compounds were tested for antibacterial activity.Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 μg/mL) than other compounds.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, Abdul Wali Khan University Mardan, Anbar Campus 23200, Pakistan; E-Mail: waqar679@yahoo.co.uk.

ABSTRACT
Two new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew. The compounds were tested for antibacterial activity. Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 μg/mL) than other compounds. This compound also exhibited weak antimicrobial activities against Staphylococcus aureus (MIC, 25 μg/mL), Pseudomonas aeruginosa (MIC, 50 μg/mL) and Salmonella typhi (MIC, 50 μg/mL).

Show MeSH
Related in: MedlinePlus