Hypophyllanthin

Phyllanthus urinaria L. P. niruri Li P. reticulatus Poiret Ye Xia Zhu Zhu Zi Cao (fruit, leaf) Phyllanthine, phyllantidine. In leaf, phyllanthin, hypophyllanthin, niranthin, nirtetralin, phylteralin.33 Treat coughing, promote digestion and secretion. 

In certain cases, structure elucidation of aryltetralin lignans has only been established by total synthesis of the ( )-compounds. Noteworthy in this respect have been the constituents of Phyllanthus nlruri Linn. (Euphorbiaceae), extracts of which have been used medicinally (in treatment of asthma, jaundice and bronchial infections) (140). Considerable confusion resulted mainly from differing interpretations of spectroscopic data, and at least five different structures were proposed for the major constituent, hypophyllanthin. The structure of the aryltetralin constituents established by unequivocal synthesis (141) are shown in Scheme 30 they were given the names hypophyllanthin (1411. nirtetralin (1421. phyltetralin (1431 and lintetralin (1441. 

Phyllanthin and hypophyllanthin from Phyllanthus amarus had no cytotoxic activity against different cultured mammalian cells, but both enhanced the cytotoxic response mediated by vinblastine with multidrug-resistant KB cells, and phyllanthin displaced the binding of vinblastine to membrane vesicles derived from this cell line, probably by an interaction with the P-glycoprotein [124],... 

Hussain et al. [202] isolated three lignans from Phyllanthus niruri which were identified as phyllanthin, hypophyllanthin and nirtetralin. They were also found to inhibit [125I]-ET-1 binding to the recombinant human ETA receptor expressed in Chinese hamster ovary cells (CHO-ETa), but were inactive against the recombinant ETb receptor. Hypophyllanthin was the most potent compound, with an IC50 value of 40 pM. 

Ganeshpure P A, Schneiders G E, Stevenson R 1981 Structure and synthesis of hypophyllanthin, nirtetralin, phyltetralin and lintetralin. Tetrahedron Lett 22 393-396... 

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