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Nine undescribed monoterpene phenol dimers, bisbakuchiols D-L (1–9), were isolated from the fruits of Psoralea corylifolia L. Their structures were elucidated based on extensive spectral analysis. The absolute configurations of 1–9 were specified by experimental and quantum chemical calculations of ECD spectra, and that of 1 was further established by X-ray diffraction analysis using Cu Kα radiation. Bisbakuchiols (1–4) were composed of two bakuchiols, one of which was cyclized via a C-7′/ C-12′ single bond to form a six-member ring, and connect to each other by C–4–O–C–13' bonds. Bisbakuchiols (7–9) had a pyran ring by linkage of C–8–O–C–12. In the enzyme assay, compounds 5 and 9 exhibited significant PTP1B inhibitory activities with IC50 values of 0.69 and 0.73 μM, and compounds 1 and 3 showed moderate PTP1B inhibitory activities. Furthermore, a molecular docking simulation of PTP1B and active compounds 5 and 9 showed that these active compounds possess low binding affinities ranging from −6.9 to −7.1 kcal/mol.

Two novel γ-lactone derivatives, trigoheterophines A (1) and B (2), together with four known furan derivatives (3–6), were isolated from the stems and leaves of Trigonostemon heterophyllus. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparing with the data reported in literature. Among them, trigoheterophines A (1) and B (2) represent an unusual type of γ-lactone derivatives, possessing 21 carbon atoms on the carbon skeleton, and known compouds (3–6) are rare furan derivatives in the plant kingdom with diverse long-chain hydrocarbyl groups as substituents at C-4. All isolated compounds were evaluated for their antiproliferative activities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1–6 showed significant antiproliferative effects against various human cancer cell lines with IC50 values ranging from 0.28 to 12.06 μM. These findings suggest that the discoveries of these novel γ-lactone derivatives and furan derivatives with significant antiproliferative activities isolated from T. heterophyllus could be of great importance to the development of new anticancer agents.

Protein tyrosine phosphatase 1B (PTP1B) is emerging as a promising yet challenging target for drug discovery. To identify natural products as new prototypes for PTP1B inhibitors, we employed a hierarchical protocol combining ligand-based and structure-based approaches for virtual screening against natural product libraries. Twenty-six compounds were prioritized for enzymatic evaluation against PTP1B, and ten of them were recognized as potent PTP1B inhibitors with IC50 values at the micromolar level. Notably, nine compounds demonstrated evident selectivity to PTP1B over four other PTPs, including the most homologous T-cell protein tyrosine phosphatase (TCPTP). The results implicated that the structural uniqueness of the natural products might be a potential solution to the selectivity issue associated with the target PTP1B.

Six new polyoxygenated seco-cyclohexenes, artahongkongenes A–F (1–6), together with six known analogues (7–12) were isolated from the stems and leaves of Artabotrys hongkongensis. Their structures were elucidated by extensive spectroscopic methods. All new compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. New seco-cyclohexenes 1–6 showed significant inhibitory effects against various human cancer cell lines with IC50 values ranging from 0.26 to 16.58 μM.