No abstract

No abstract

No abstract

Fifty-seven tannins and related compounds, including gallotannins, ellagitannins, and condensed and complex tannins, were evaluated for their cytotoxicities against human tumor cell lines, including malignant melanoma, lung carcinoma, ileocecal adenocarcinoma, epidermoid carcinoma, malignant melanoma, and medulloblastoma cell lines. Among them, chebulagic acid [1], geraniin [2], sanguiin H-11 [3], 4,5-di-O-galloylquinic acid [12], 1,3,4,5-tetra-O-galloylquinic acid [15], 1(beta)-O-galloylpedunculagin [24], furosin [29], castalagin [38], sanguiin H-2 [34], vescalagin [39], grandinin [40], phyllyraeoidin A [42], (-)-epicatechin 3-O-gallate [50], cinnamtannin B2 [55], and acutissimin A [56] exhibited moderate selective cytotoxicity against PRMI-7951 melanoma cells with ED50 values in the range of 0.1-0.8 microgram/ml. Selective cytotoxicities against the melanoma cells were also observed for strictinin [22], pedunculagin [23], eugeniin [25], elaeocarpusin [28], punicacortein C [37], casuarinin [41], sanguiin H-6 [43], procyanidin B-2 3,3'-di-O-gallate [51], procyanidin C-1 3,3',3"-tri-O-gallate [52], and cinnamtannin B1 [54] with ED50 values of 1-4 micrograms/ml. All of the tannins were found to be inactive (greater than 10 micrograms/ml) against lung carcinoma (A-549), ileocecal adenocarcinoma (HCT-8), epidermoid carcinoma of nasopharnyx (KB), and medulloblastoma (TE-671) tumor cells.

No abstract

No abstract

No abstract

Nine tannins, including gallo- and ellagitannins, were evaluated as potential inhibitors of HIV replication. 1,3,4-Tri-O-galloylquinic acid [1], 3,5-di-O-galloyl-shikimic acid [2], 3,4,5-tri-O-galloylshikimic acid [3], punicalin [6], and punicalagin [7] inhibited HIV replication in infected H9 lymphocytes with little cytotoxicity. Two compounds, punicalin and punicacortein C [8], inhibited purified HIV reverse transcriptase with ID50 of 8 and 5 microM, respectively. Further studies with H9 lymphocytes indicated that chebulagic acid [5] and punicalin did not inactivate virus directly. However, 1,3,4-tri-O-galloylquinic acid and 3,5-di-O-galloylshikimic acid were more effective inhibitors under those conditions. All tannins appear to inhibit virus-cell interactions. Thus, inspite of their anti-RT activity, the mechanism by which tannins inhibit HIV may not be associated with this enzyme.