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Two galloylglucosides, 6-hydroxy-eugenol 4-O-(6′-O-galloyl)-β-D-4C1-glucopyranoside (4) and 3-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol-2-O-(2′,6′-di-O-galloyl)-β-D-4C1-glucopyranoside (7), and two C-glycosidic tannins, vascalaginone (10) and grandininol (14), together with fourteen known metabolites, gallic acid (1), methyl gallate (2), nilocitin (3), 1-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-(α/β)-d-glucopyranose (5), 4,6-(S)-hexahydroxydiphenoyl-(α/β)-d-glucopyranose (6), 3,4,6-valoneoyl-(α/β)-d-glucopyranose (8), pedunculagin (9), casuariin (11), castalagin (12), vascalagin (13), casuarinin (15), grandinin (16), methyl-flavogallonate (17) and ellagic acid (18), were identified from the leaves of Pimenta dioica (Merr.) L. (Myrtaceae) on the basis of their chemical and physicochemical analysis (UV, HRESI-MS, 1D and 2D NMR). It was found that 9 is the most cytotoxic compound against solid tumour cancer cells, the most potent scavenger against the artificial radical DPPH and physiological radicals including ROO•, OH•, and O2-•, and strongly inhibited the NO generation and induced the proliferation of T-lymphocytes and macrophages. On the other hand, 3 was the strongest NO inhibitor and 16 the highest stimulator for the proliferation of T-lymphocytes, while 10 was the most active inducer of macrophage proliferation.

Three new acylated quercetin rhamnosides have been isolated from the leaves and stem of Calliandra haematocephala Hassk. (Fabaceae) and their structures were established as quercitrin 2''-O-caffeate (1), quercitrin 3''-O-gallate (2) and quercitrin 2'',3''-di-O-gallate (3). Also, 17 known compounds were identified as gallic acid (4), methyl gallate (5), caffeic acid (6), myricitrin (7), quercitrin (8), myricetin 3-O-beta-D-4C1-glucopyranoside (9), afzelin (10), isoquercitrin (11), myricetin 3-O-(6''-O-galloyl)-beta-D-glucopyranoside (12), myricitrin 2''-O-gallate (13), quercitrin 2''-O-gallate (14), afzelin 2''-O-gallate (15), myricitrin 3''-O-gallate (16), afzelin 3''-O-gallate (17), 1,2,3,4,6-penta-O-galloyl-beta-D-4C1-glucopyranose (18), myricitrin 2'',3''-di-O-gallate (19), quercetin 3-O-methyl ether (20), for the first time from the genus Calliandra except for 6. Compounds 7, 8, 13, 14, 16 and 19 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical, superoxide anion generation and DPPH radical in comparison with that of quercetin as a positive control in vitro. Compounds 7 and 8 exhibited lethal effect towards brine shrimp Artemia salina.

A novel biflavone di-C-glucoside, 6,6″-di-C-β-D-glucopyranoside-methylene-(8,8″)- biapigenin (1), was isolated from the leaves of Jatropha curcas L. (Euphorbiaceae), together with six known compounds; apigenin 7-O-β-D-neohesperidoside (2), apigenin 7-O-β-Dgalactoside (3), orientin (4), vitexin (5), vicenin II (6), and apigenin (7). Their structures were determined on the basis of extensive chemical and spectroscopic analyses (UV, NMR and HRESI-MS). The immunomodulatory effect of an 80% aqueous methanol extract (AME) and compounds 1 - 5 (0.25 mg/kg body wt) to one-day-old specific pathogen-free (SPF) chicks was determined. Stimulation of both humoral and cell-mediated seroresponse was observed, especially those of AME and compound 1. Remarkable effective increases of the antibody titers, lymphocyte and macrophage cells, in blood were recorded. SPF chicks treated with the tested samples exhibited protection against Newcastle disease challenge virus after being vaccinated.

Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

No abstract

A novel phenylethanoid dimer, namely, jacraninoside A (1) and the five known constituents E/Z-acetoside (2), isoacetoside (3), cistanoside E (4), 6 '-acetylacetoside (5), and campneoside I (6) together with the seven flavonoids isoquercitrin (7), scutellarein 7-O-β -D-glucuronopyranoside methyl ester (8), apigenin 7-O-β -D-galacturonopyranoside (9), luteolin 7-O-β -D-glucuronopyranoside methyl ester (10), apigenin 7-O-β -D-glucuronopyranoside methyl ester (11), luteolin 7-O-β -Dglucopyranoside (12), and isovitexin (13) were isolated from the aqueous methanol extract of Jacaranda mimosaefolia D. Don. leaves. All known metabolites have been identified in this genus for the first time except for 2 and 12 which had been isolated once before from the leaves and twigs of Jacaranda mimosaefolia. Their structures were elucidated based on chemical evidences and spectroscopic analyses (1D and 2D NMR, HRMS ((-)-ESI)/MS, UV).

Four polyphenolic acid derivatives and three ellagitannins were isolated from the leaves of Melaleuca quinquenervia (Clav.) S. T. Blake for the first time. Their structures were elucidated as gallic acid (1), ellagic acid (2), 3-O-methylellagic acid (3), 3,4,3'-tri-O-methylellagic acid (4), 2,3-O-hexahydroxydiphenoyl-(alpha/beta)-D-(4)C(1)-glucopyranose (5), castalin (6) and grandinin (7) on the basis of chemical, mass spectrometric (-ve ESI-MS) and spectroscopic (UV, (1)H-, (13)C NMR, (1)H,(1)H-, (1)H,(13)C-COSY, (1)H,(1)H-TOCSY and HMBC) analyses. Grandinin (the major compound) showed radical scavenging properties by its reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical [EC(50) = 4.3 +/- 0.3 micro g mL(-1)]. It was found to be relatively nontoxic in mice [LD(50) = 316 mg Kg(-1) b.wt.]. It exhibited a significant dose-dependent (35-70 mg Kg(-1)) hypoglycemic effect by significantly reducing blood glucose level in basal condition and after heavy glucose load in normal mice. Moreover, it reduced the elevated blood glucose level in STZ-induced diabetic mice. In addition, grandinin reduced the elevated blood urea nitrogen and serum lipid peroxides in STZ-induced diabetic mice.