Jaf, Muhammad Tahir Muhammad Al (2025) Anti-Diabetic Activity Of Chemical Constituents Isolated From Kopsia Teoi And Catharanthus Roseus (Apocynaceae), And Corrosion Inhibition Studies Of Its Extracts. PhD thesis, Perpustakaan Hamzah Sendut.
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Abstract
This research involved extracting dried ground bark from kopsia teoi (k. Teoi) and catharanthus roseus (c. Roseus) using n-hexane, dichloromethane (dcm), and methanol (meoh) solvents to produce the crude extracts. Alkaloids were isolated from dragendorff-positive dcm extracts via acid-base extraction with hcl and nh4oh, yielding a dcm alkaloid extract. Fractionation by cc and analysis by tlc led to further purification, isolating alkaloids. From k. Teoi, ten compounds were isolated, including four new compounds: 16-epi-deacetylakuammiline n(4)-methylene chloride (602), n(1)-methoxycarbonyl-11-methoxy-12-hydroxy-δ14‒17-kopsinine (603), n(1)-methoxycarbonyl-11,12-methylenedioxy-δ14‒17-kopsinine (604), and n(4)-hydroxymethyl-kopsinine (605). Additionally, known compounds were isolated, including leuconolam (301), kopsiloscine g (413), e-akuammidine (132), n(1)-methoxycarbonyl-12-methoxy-δ16,17-kopsinine (302), kopsininate (312), and n(1)-methoxycarbonyl-11,12-methylenedioxy-δ16,17-kopsinine (383). Meanwhile, from c. Roseus, five compounds were isolated, including one new compound: 16-epi-deacetylakuammiline-7-methyl-n(4)-methylene chloride (606), and four known compounds, namely: β-amyrin (590), ursolic acid (591), dodecanoic acid (596), and oleic acid (598). The isolated compounds were characterised using ft-ir (atr), 1d- and 2d- nmr, uv spectroscopy, and high-resolution electrospray ionisation mass spectroscopy (hresims), with comparison to literatures data.
| Item Type: | Thesis (PhD) |
|---|---|
| Subjects: | Q Science > QD Chemistry > QD1-999 Chemistry |
| Divisions: | Pusat Pengajian Sains Kimia (School of Chemical Sciences) > Thesis |
| Depositing User: | Mr Hasmizar Mansor |
| Date Deposited: | 23 Jun 2026 00:54 |
| Last Modified: | 23 Jun 2026 00:54 |
| URI: | http://eprints.usm.my/id/eprint/64425 |
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