Ganodermasides E-H, four new ergosterol derivatives from the endophytic fungus Epicoccum poae DJ-F associated with Euphorbia royleana.

Ganodermasides E-H (1-4), four new ergosterol derivatives and two known ones (5 and 6) were isolated from the fermentation of the endophytic fungus Epicoccum poae DJ-F in the stems of Euphorbia royleana Boiss. Their structures were elucidated by spectroscopic analysis, including extensive 1D NMR, 2D NMR, and HRESIMS techniques. All the isolated compounds were tested for their vitro antibacterial activity. Compounds 1-6 showed weak inhibitory effects on Staphylococcus epidermidis, Pseudomonas syringae, and Ralstonia solanacearum with MIC values ranging from 0.4 to 3.6 mM.

Macathioureas A-D, four new thiourea analogues from the roots of Lepidium meyenii.

Macathioureas A-D (1-4), four new thiourea derivatives with a carbamothioylpyrrolidine-2-carboxamide framework, were isolated from the roots of Lepidium meyenii (Maca) collected from Qujing, Yunnan Province of China. Their structures were identified based on extensive spectroscopic data, including 1D NMR, 2D NMR, and HRESIMS techniques. Their absolute configurations were assigned as 7S by the comparison of the experimental and predicted electronic circular dichroism (ECD) spectra. All the thiourea analogues were tested for their cytotoxicities against five human cancer cell lines. However, no significant activities were detected at concentrations up to 40 µM.

Phyllaciduloids E and F, two new cleistanthane diterpenoids from the leaves of Phyllanthus acidus.

Phyllaciduloids E (1) and F (2), two new cleistanthane diterpenoids, were isolated from the leaves of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their planar structures were established by spectroscopic analysis and comparison with literature values. The relative configurations of phyllaciduloids E and F were confirmed by DFT-NMR chemical shift calculations and subsequent CP3 probability methods. Phyllaciduloids E and F were evaluated for their cytotoxicity. However, no significant activities were detected at concentrations up to 40 µM.[Formula: see text].

New cytotoxic dichapetalins in the leaves of Phyllanthus acidus: Identification, quantitative analysis, and preliminary toxicity assessment.

The young leaves of Phyllanthus acidus (Euphorbiaceae) are commonly used as edible vegetables in Indonesia, Thailand, and India, and their water infusions as dieting aids for people trying to remain slim. However, it is regarded as a poisonous plant in Malaya, and current researches are insufficient to provide a conclusion on its toxicity and safety under large doses. In this study, we firstly found that the refined nonpolar extracts of P. acidus leaves showed significant cytotoxic effect against BEAS-2B and L02 normal cell lines with IC50 values of 2.15 and 1.64 mg/mL, respectively. Further bioactivity-guided isolation produced four new rare dichapetalins (pacidusins A-D) from the most active fraction. Their structures including absolute configurations were elucidated by extensive spectroscopic data and X-ray diffraction analysis. All the isolated dichapetalins exhibited moderate cytotoxicity against, BEAS-2B and L02 normal cell lines with IC50 values ranging from 12.44 to 22.55 µM, as well as five human cancer cell lines with IC50 values ranging from 3.38 to 22.38 µM. Furthermore, the content of the main dichapetalins in the leaves were determined by analytical HPLC, which showed that the leaves contained a very high amount of the four isolated dichapetalins with a total yield of 0.488 mg/g of dry plant material. These toxic dichapetalins may lead to adverse health effects in higher doses. Our findings indicate that the dichapetalin containing leaves may not be suitable for consumption in large quantities as food, but demonstrate their potency as anti-cancer agents for new drug discovery.

Phyllanacidins A-C, three new cleistanthane diterpenoids from Phyllanthus acidus and their cytotoxicities.

Phytochemical investigation on the nonpolar extracts of P. acidus leaves afforded three new cleistanthane diterpenoids, named phyllanacidins A-C (1-3), in addition to three known ones (4-6). Among them, compounds 2 and 3 represent the first examples of 17-nor cleistanthane diterpenoids. Their structures including absolute configurations were elucidated on the basis of extensive spectroscopic data and single crystal X-ray diffraction analysis. All the isolated cleistanthane diterpenoids were evaluated for their cytotoxic activities against five human cancer cell lines. Compounds 4-6 exhibited moderate cytotoxicity with IC50 values ranging from 16.11 to 30.82 µM.

Biomimetic Synthesis of Macahydantoins A and B from Lepidium meyenii, and Structure Revision of Macahydantoin B as a Class of Thiohydantoin with a 4-Methyl-hexahydropyrrolo[1,2-c]imidazole Skeleton.

Phytochemical investigation on Lepidium meyenii led to the discovery of macahydantoin C (3), a new thiohydantoin with a 1,3-diazabicyclo[3.3.1]nonane core, the spectral properties of which indicate a potential structural misassignment of its previously reported analogue, macahydantoin B (2a). To probe this hypothesis, a concise, scalable, and biomimetic synthesis of the originally proposed 2a and its revised structure (2b) was efficiently accomplished using the modified Edman degradation as the key step from commercially available materials in 65% (three steps) and 52% (three steps) overall yields, respectively. These synthetic endeavors undoubtedly reassigned the structure of macahydantoin B as an unreported type of thiohydantoin featuring a 4-methyl-hexahydropyrrolo[1,2-c]imidazole scaffold.

Catalytic Asymmetric Formal Total Synthesis of (-)-Triptophenolide and (+)-Triptolide.

Catalytic asymmetric formal synthesis of (-)-Triptophenolide and (+)-Triptolide have been achieved. Key reaction involves Palladium catalyzed asymmetric conjugate addition of aryl boronic acid to 3-methyl cyclohexe-1-none to form quaternary carbon. Claisen rearrangement and subsequent aldol reaction furnished trans-decaline key intermediate, which assured a formal total synthesis of (-)-Triptophenolide and (+)-Triptolide.

Scopariusins, a new class of ent-halimane diterpenoids isolated from Isodon scoparius, and biomimetic synthesis of scopariusin A and isoscoparin N.

Scopariusins A-C (1-3), three novel rearranged ent-halimanoids with a bicycle[5.4.0]undecane ring system, two new normal ent-halimanoids (4 and 5), and a new ent-clerodanoid (6) were isolated from Isodon scoparius. Moreover, a biomimetic transformation from the ent-clerodanoid to the normal and the rearranged ent-halimane diterpenoids was successfully accomplished, which not only validated the biogenetic hypothesis in this plant but also confirmed the absolute configurations of 1 and 5.