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Chemical investigation of the twigs of Cleistanthus sumatranus (Phyllanthaceae) led to the isolation of 10 undescribed lignans, sumatranins A-J ( 1 - 10 ). Compounds 1 - 4 are unprecedented furopyran lignans characterized by a unique 2,3,3a,9a-tetrahydro-4 H -furo[2,3- b ]chromene heterotricyclic framework. Compounds 9 and 10 are rare 9'- nor -dibenzylbutane lignans. Structures were established based on analyses of spectroscopic data, X-ray crystallographic data, and experimental ECD spectra. Immunosuppressive assays revealed compounds 3 and 9 displayed moderate inhibitory effects with good selectivity indexes against LPS-induced B lymphocyte proliferation.

Spicatulides A-G ( 1 - 7 ), seven new phenolic-monoterpenoid hybrid molecules, along with two known compounds, 8 and 9 , were isolated and identified from Chloranthus spicatus . Compound 1 represents an unprecedented skeleton featuring an aryl-fused 2-oxabicyclo[4.3.1]decane moiety, and compound 2 is the first example of a denudaquinol-normonoterpenoid adduct. Their structures with absolute configurations were elucidated on the basis of spectroscopic data analyses and TDDFT-ECD calculations. Compounds 3 , 5 , 6 , and 9 exhibited the activity of reducing lipogenesis in HepG2 cells in a dose-dependent manner.

As a plant used in both food and medicine, Sauropus spatulifolius is consumed widely as a natural herbal tea, food source, and Chinese medicine. Inspired by its extensive applications, we conducted a systematic phytochemical study of the leaves of S. spatulifolius . Thirteen new diterpenoids, sauspatulifols A-M ( 1 - 13 ), including four ent -cleistanthane-type diterpenoids ( 1 - 4 ), eight 15,16-di- nor - ent -cleistanthane-type diterpenoids ( 5 - 12 ), and one 17- nor - ent -pimarane-type diterpenoid ( 13 ) as well as one known diterpenoid, cleistanthol ( 14 ), were isolated. All of these diterpenoids feature a 2α,3α-dihydroxy unit within the A ring, and their structures were elucidated by spectroscopic data analysis, electronic circular dichroism calculations, and single-crystal X-ray diffraction analysis. Compound 14 displayed moderate inhibitory activity against Staphylococcus aureus , Staphylococcus epidermidis , Bacillus subtilis , and Shigella flexneri with the same minimum inhibitory concentration value of 12 μg/mL as well as activity against vesicular stomatitis virus and influenza A virus.

Fifteen new labdane-type diterpenoids, sublyratins A-O ( 1 - 15 ), along with four known analogues ( 16 - 19 ) were isolated from the aerial parts of Croton sublyratus . Their structural assignments were challenging due to the stereoisomeric features evident and were achieved by analyzing comprehensively the spectroscopic data and electronic circular dichroism spectra and using X-ray crystallographic analysis. Compounds 9 and 16 - 18 displayed cytotoxic activity against the HL-60 cell line with IC 50 values of 1.5-2.8 μM.