Contribution to the study of polyphenolic compounds of four biologically active plant species: rumex chalepensis, R. nepalensis (polygonaceae), indigofera hebepetala and I. cassioides (leguminosae)

Abstract

Qualitative, quantitative and anti-bacterial activity analysis of flavonoids of 20 plant species of Islamabad and its surroundings were carried out. On the basis of results obtained after these analysis the plant species namely Rumex chalepensis and indigofera hebepetala were selected for detailed study of their flavonoid contents. ......................................................................

Qualitative, quantitative and anti-bacteria! activity analysis flavonoids of 20 plant species of Islamabad and its surroundings were carried out. On the basis of results obtained after these analysis the plant species namely Rumex chalepensis and Indigofera hebepetala were selected for detailed study of their flavonoid contents. In addition, to the two plant species cited above, another two species belo!,!ging to the same genera i,e. Rumex nepaiensis and Indigo/era cassioides were also selected for similar studies. Apart from the chapter on the methodology used during the course of this study the present dissertation is further divited into three chapters. The first is devoted to the isolation and structural elucidation of flavonoids and related compounds from the leaves of R. chalepensis and R. nepalensis, whereas the second chapter deals with the similar work done on 1. hebepetala (flowers and leaves) and leaves of 1. cassioides. In the course of these studies a total of 6 new and 13 known/rare compounds were isolated and identified from the following four plant species under investigation: Rumex chalepensis a. New compounds HO OH o o OH OH I OH ~~)~~H~~H O~OH HO Quercetin 3-0-~-D-glucopyranosyl(1-74 )-~-D-galactopyranoside (RC-J) 1 OH I~L--'--;r-.. 0 HO-7--..t:""--" OH ___J --- o ----L-OH OH OH o o HO 5 o 6,8-dihydroxy-3-methyl-anthraquinone-l-O-1.l-D-glucosyl( 1-.>4 )-a-L-rhamnoside (RC-5) b. Known rare compounds KaempferoJ 3-0-a-L-rhamnopyranosyl(l-+6)-p-D-galactopyranoside (RC-2) c. Known common compounds Quercetin 3-0-a-L-rhamnopyranosyl( 1-+6)-P-D-glucoyranoside (RC-3) Quercetin 3-0-a-L-rhamnopyranoside (RCA) 3,5,7, 4'-tetrahydroxy-3', 5'-dimethoxy anthocyanidin (Malvidin) (RC-IA) Rumex nepafellsis a. Known rare compounds Quercetin 3-0-P-D-glucopyranosyl(1 -+4)-p-D-galactopyranoside (RN-I) Kaempferol 3-0-a-L-rhamnopyranosyl(l-+6)-p-D-galactopyranoside (RN-2) 2 b. Known common compounds Quercetin 3-0-a-L-rhamnopyranosyl(l ~6)-/3-D-glucoyranoside (RN-3) Quercetin 3-0-a-L-rhamnopyranoside (RN-4) 1, 6, 8-trihydroxy-3-methyl anthraquinone (RN-5) 3,5,7, 4'-tetrahydroxy-3', 5'-dimethoxy anthocyanidin (Malvidin) (RN-IA) Indigofera Izebepetala (Flowers) a. New compounds '-':::: OH HO 0 HO 0 '-':::: ~ HO OH ~ OH 0 OH OH 0 OH OH 013 Kaempfero I 3-0-a-L-rhamnopyranosy I (1 ~ 2)-j3-D-galactopyranoside-7 -O-a-L-arabinofuranoside (lHF -J) 3 o OH o OH o ----~-~OH !:::":\-~/ 0 Kaempfero 1 3-0-a-L-rhamnopyranosyl (1->6)-13-D-galactopyranoside-7 -O-a -L-arabinofuranoside (IHF-2) b. Known rare compounds Kaempferol 3-0-a-L-arabinopyranoside-7 -O-a-L-rhamnopyranoside (II IF -3) Kaempferol 3-0-a-L-rhamnopyranoside-7 -O-a-L-arabinopyranoside (IHF -4) c. Known common compounds Kaempferol 7 -O-a-L-rhamnopyranoside (IHF-5) 3, 5, 7,}', 4'-pentahydroxy anthocyanidin (Cyanidin) (lHF-l A) 3,5,7,3',4', 5'-hexahydroxy anthocyanidin (Delphinidin) (IHF-2A) 4 Indigofera hebepetala (Leaves) a. New compounds o o G-i 0 Kaempferol 7 -O-~-D-allopyranoside (IHL-I) ~ G-i 0 c:?' 0 ~ ~ 0 G-i G-i 0 0 HO OH Kaempferol 3, 7-0-a-L-diarabinopyranoside (IHL-2) b. Known rare compounds Kaempferol 3-0-a-L-arabinopyranoside-7-0-a-L-rhamnopyranoside (IHL-3) Kaempferol 3-0-a-L-rhamnopyranoside-7-0-a-L-arabinopyranoside (IHL-4) 5 C, Known common compound 3,5,7,3', 4'-pentahydroxy anthocyanidin (Cyanidin) (IHL-IA) Indigofera cassioides a, Known common/rare compounds Kaempferol 7-0-a-L-rhamnopyranoside (IC-2) Kaempferol 3-0-(Galactose + Rhamnose) (IC-3) Quercetin 3-0-p-D-galactopyranoside (IC-4) Quercetin 3-0-(Glucose + Arabinose) (IC-5) Structural determinations were mainly based on NMR [IH NMR, IJC (B,B and DEPT) NMR] spectral assignments which were confirmed by homo and hetero COSY experiments and by homo nuclear NOE difference experiments, The conclusions drawn from NMR spectral analysis were further confirmed by the mass spectra (ElMS and F ABMS), UV analysis in methanol before and after the addition of shift reagents and cochromatography, Amount of flavonoids in mg/gm as well as the number of flavonoids oresent in each plant specie are tabulated in the final portion of the dissertation. Antibacterial activity of the global flavonoid extracts as well as of the isolated purified flavonoids is also listed in the same section"The antibacterial activity analysis exhibited significant antibacterial activity for the global flavonoid extracts of Rumex chalepensis and Indigo/era hebepetala, However this activity was enhanced when the purified flavonoids 6 of Rumex chalepensis and Indigofera hebepetala were tested against different bacterial strains (Staphylococcus aureus, Sarcina lutea, Bacillus subtilis, Escherchia coli and Psudomonas Gueror;inosa).