Phytochemical study and microbial bioconversion of selected biologically active natural products /
دراسة فيتوكيميائية و تحول ميكروبى لبعض المنتجات الطبيعية المختارة ذات التأثير البيولوجى
Rabab Mahrous Abdou Hussein ; Supervised Aly Mohamed Elsayed , Nebal Darwish Eltanbouly , Riham Salah Eldine Elsayed
- Cairo : Rabab Mahrous Abdou Hussein , 2021
- 237 P. : charts , facsimiles ; 25cm
Thesis (Ph.D.) - Cairo University - Faculty of Pharmacy - Department of Pharmacognosy
A phytochemical study of Aframomum melegueta K. Schum seeds was conducted to investigate its phenolics. A. melegueta K. schum constituents were characterized and its major phenolics were isolated using LC-ESI/Triple TOF/MS and chromatographic techniques, respectively. Then, RP-HPLC was used for quantitative estimation of A. melegueta K. schum major phenolics. A Box-Behnken design was used to determine the effect of three extraction parameters (extraction time, methanol concentration and liquid/solid ratio) on the extraction yield of A. melegueta K. schum phenolics. Seventy-three compounds were detected including phenolic acids, hydroxyphenylalknes, diarylheptanoids and fatty acids. Among them, 38 were reported for the first time in A. melegueta K. schum seeds. Four hydroxyphenylalkanes (6-paradol, 6-shogoal, 6-dehydrogingerdione and 6-gingerol) and one diarylheptanoid (3-acetoxy-1-(4`,5`-dihydroxy-3`-methoxy-phenyl)-7-(3``,4``dihydroxyphenyl) heptane) were isolated. A.melegueta K. schum seeds methanol extract was found to contain 8.29, 4.03 and 11.29 mg\g DW of 6-gingerol, 6-shogaol and 6-paradol, respectively.The methanol concentration and liquid/solid ratio have significant effect on the Ultrasonic-assisted extraction of A. melegueta K. schum phenolics, while the extraction time has no impact.The optimized extraction conditions were validated and are recommended for the extraction of A. melegueta K. schum major constituents
Aframomum melegueta K. Schum LC-ESI/Triple TOF/MS Microbial Biotransformation