[Show abstract][Hide abstract] ABSTRACT: Rhizoma Paridis, the root of Paris polyphylla var. yunnanensis (Trilliaceae), is a Chinese traditional medicine, which resources become less and less. However, the aerial parts of this herb, which can regenerate every year, were discarded. In order to expand the resources, detailed chemical investigation on the stems and leaves of Paris polyphylla var. yunnanensis led to isolation of one sapogenin and 24 steroidal saponins (1-25), including 6 new glycosides, named chonglouosides SL-1-SL-6 (1-6). Their structures were elucidated on the basis of detailed analyses of their 1D and 2D NMR spectra and acid hydrolysis. Among them, compounds 3 and 4 are the first 23,27-dihydroxydiosgenin saponin having a sugar chain attached to C-23 or C-27, while compound 6 is the first 27-hydroxyruscogenin glycoside bearing 1, 27-di-O-sugar chains. The known compounds 10, 12, 14, 19, 20, 22, and 25 were isolated from the genus Paris for the first time. Antimicrobial testing activities of the selected compounds showed that compound 2, 3, 6, 8, 9, 11, 13, 17, 18, 21, and 24 were active against Propionibacterium acnes with MIC values of 62.5, 62.5, 3.9, 16.5, 17.2, 7.8, 39.0, 17.2, 31.3, 62.5, and 31.3μg/ml, respectively.