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Two novel fungal polyketides, phometides A (1) and B (2), together with four known compounds (3–6), were isolated from the endophytic fungus Phoma sp. YUD17001 obtained from Gastrodia elata Blume. The structures were elucidated based on spectroscopic analyses, X-ray crystal diffraction, and time-dependent density functional theory/electronic circular dichroism (TDDFT/ECD) calculations. Structurally, phometide A (1) represented the first example of C 12 polyketide characterized by an unusual tetrahydrobenzofuran-3(2 H)-one core with an α , β -unsaturated ketone functionality, while phometide B (2) was an unprecedented molecule containing a 2-pentylcycloheptan-1-one scaffold. In an antimicrobial activity assay, phometide A (1) exhibited significant inhibitory activity against Staphylococcus aureus with MIC value of 4 μg/mL. Phometide B (2) showed moderate antifungal activity against Candida albicans with an MIC value of 16 μg/mL. Furthermore, compounds 1 and 2 were evaluated for their acetylcholinesterase inhibitory and cytotoxic activities. [Display omitted] • Two novel fungal polyketides were identified from the endophytic fungus Phoma sp. YUD17001. • Phometide A possess an unusual tetrahydrobenzofuran-3(2 H)-one functionality. • Phometide B is a novel polyketone containing a 2-pentylcycloheptan-1-one scaffold. • Phometides A and B demonstrated antimicrobial activity against S. aureus and C. albicans , respectively. [ABSTRACT FROM AUTHOR]

Three undescribed compounds (1 – 3), including two butenolides and one indol alkaloids. Together with twenty-one known compounds (4 – 24) were isolated and identified from Lepidium obtusum Basin. Their structures were elucidated by spectroscopic analysis and ECD calculations. The isolated compounds were tested for their antimicrobial, antioxidant, and anti-inflammatory activities. Among them, compounds 11 , 12 , 14 , 21 and 23 showed moderated antimicrobial activities against (Candida albicans , E. coli , Staphylococcus aureus). Compounds 11 , 12 , 14 , 15 , 17 and 18 exhibited potent antioxidant activities against ABTS and DPPH. Compound 1 exhibited moderated anti-inflammatory activities. Compounds 4 – 24 were isolated from this plant for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]

Nine previously undescribed compounds including six tocopherol derivatives (1 – 6) and three acylphloroglucinol derivatives (7 – 9) were isolated and characterized from the plants of Dryopteris crassirhizoma. Their structures with absolute configurations were determined by extensive spectroscopic analyses, including IR, HRESIMS, NMR, and calculated electronic circular dichroism (ECD). Compounds 1 and 2 are the first tocopheroid derivatives possessing unique 2,5-dimethylcyclopent-4-ene-1,3-dione carbon skeleton, and compounds 3 – 6 were new 5a-norcyclopentenones having a spirofused bicyclic carbon skeleton. The biosynthetic pathway of compounds 1 – 6 was postulated. When combined with fluconazole (FLC), compound 3 showed significant antifungal activity against standard Candida albicans with MIC 50 value of 1.19 μg/mL (FLC: 3.41 μg/mL). Furthermore, the anti-plant pathogenic fungi and bacterial activities have been evaluated in vitro, compounds 5 and 8 showed anti- Verticillium dahlia and Sclerotinia sclerotiorum with MIC value of 50 μg/mL, respectively. Compounds 1 and 5 exhibited moderate antibacterial activities against Micrococcus luteus with MIC value of 50 μg/mL, respectively. [Display omitted] • Nine previously undescribed compounds were isolated from Dryopteris crassirhizoma. • The quantum calculation of electronic circular dichroism (ECD) data was applied for structure elucidation. • A biosynthesis of the tocopherol derivatives were assumed. • The antifungal and antibacterial activities of these compounds were evaluated. [ABSTRACT FROM AUTHOR]

Croton kongensis Gagnepain. belongs to the genus Croton , the Euphorbiaceae family, mainly distributed in Hainan and southern Yunnan, China. The aim of present study was to acquire secondary metabolites of the ethanol extract obtained from the leaves and twigs of C. kongensis. Three new abietane-type diterpenoids, crokongenolides A-C (1 – 3), together with seven known diterpenoids (4 – 10), were isolated from the leaves and twigs of C. kongensis. The structures of the new compounds were determined by extensive spectroscopic methods (1D and 2D NMR, IR, and HRESIMS), and their absolute configurations were confirmed by single-crystal X-ray diffraction analysis or electronic circular dichroism (ECD) calculations. The absolute configuration of 4 was determined for the first time by single-crystal X-ray diffraction analysis with Cu-Kα irradiation. Some compounds were evaluated for their antimicrobial properties by assessing their inhibitory effects on Staphylococcus aureus , Candida albicans , and Escherichia coli. Compound 10 showed significant antimicrobial activity against S. aureus with MIC value of 1.56 μg/ml. [Display omitted] • Three new abietane-type diterpenoids were isolated from the leaves and twigs of Croton kongensis. • The structures of three new compounds were elucidated by extensive analysis of spectroscopic data. • Some compounds showed significant antimicrobial activity against Staphylococcus aureus. [ABSTRACT FROM AUTHOR]