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Lycoplanine A (1), a Lycopodium alkaloid with a 6/9/5 tricyclic ring skeleton fused with the γ-lactone ring and featuring an unusual 1-oxa-6-azaspiro[4.4]nonane moiety and an unprecedented 3-azabicyclo[6.3.1]dodecane unit, was isolated from the club moss Lycopodium complanatum. The structure and absolute configuration of 1 were identified by a combination of NMR spectroscopic analysis and single-crystal X-ray diffraction. Biological studies showed that 1 is a potent Cav3.1 T-type calcium channel (TTCC) inhibitor with an IC50 value of 6.06 μM.

Lycoplanine A (1), a Lycopodium alkaloid with a 6/9/5 tricyclic ring skeleton fused with the γ-lactone ring and featuring an unusual 1-oxa-6-azaspiro[4.4]nonane moiety and an unprecedented 3-azabicyclo[6.3.1]dodecane unit, was isolated from the club moss Lycopodium complanatum. The structure and absolute configuration of 1 were identified by a combination of NMR spectroscopic analysis and single-crystal X-ray diffraction. Biological studies showed that 1 is a potent Ca

Vibsatins A (1) and B (2), a pair of 14,15,16,17-tetranorvibsane-type diterpenoids that feature a bicyclo[4.2.1]nonane moiety formed by a new C-13/C-2 bond, were isolated from the twigs and leaves of Viburnum tinus cv. variegatus. The structures and absolute configurations were elucidated by a combination of NMR spectra, optical rotation, and X-ray diffraction experiments. A possible biogenetic pathway is also proposed. Moreover, vibsatin A (1) enhanced the neurite outgrowth of NGF-mediated PC12 cells at a concentration of 10 μM.

Three rearranged labdane-type diterpenoids, hypophyllins A–C (1–3), and a caged labdane diterpenoid possessing a 8,9-dioxatricyclic[4.2.1.13,7]decane moiety, hypophyllin D (4), as well as two new biogenetically related diterpernoids, hypophyllins E (5) and F (6), were isolated from the aerial parts of Hypoestes phyllostachya “Rosea”. The absolute configurations of 1–4 were determined by X-ray diffraction analysis. The plausible biogenetic pathway for 1–4 was also proposed. Compounds 4 and 5 showed potent vasorelaxant activity on endothelium-intact thoracic aorta rings precontracted with KCl.

Five new Lycopodium alkaloids, phleghenrines A–D (1–4) and neophleghenrine A (5), were isolated from Phlegmariurus henryi (Baker) Ching. The structures and absolute configurations of 1–5 were determined using extensive spectroscopic data coupled with computational calculations and revealed 1–4 possess a bicyclo[3.2.2]nonane core, whereas 5 possesses an unprecedented 9-azaprotoadamantane core. Compounds 1 and 4 showed potent acetylcholinesterase (AChE) inhibitory activities, and 4 is a good lead natural product for the treatment of Alzheimer’s disease.

The first enantioselective total synthesis of (-)-8-deoxyserratinine has been achieved in 15 steps from enone 4 with 7% overall yield. The key features include a highly efficient Helquist annulation to furnish the cis-fused 6/5 bicycle, facile construction of the aza nine-membered ring system employing double N-alkylation strategy, as well as asymmetric Shi epoxidation, delivering the desired beta-epoxide stereospecifically.

Cernupalhine A (1) is a trace Lycopodium alkaloid (0.7 mg) possessing a new C17N skeleton with an unusual hydroxydihydrofuranone motif newly isolated from Palhinhaea cernua L. Its complete structural assignment, including absolute stereochemistry, was established through a combination of high-field NMR techniques and computational methods and further unequivocal confirmation by the first asymmetric total synthesis. Following the first total synthesis of lobscurinine (3), 1 was achieved via regio- and stereoselective cyanide ion addition and subsequent acid treatment.

A new pentacyclic (5/6/6/6/7) Lycopodium alkaloid named isopalhinine A (1), which possesses a sterically congested architecture built with a tricyclo[4.3.1.0(3,7)]decane (isotwistane) moiety and a 1-azabicyclo[4.3.1]decane moiety, and palhinines B (2) and C (3) were isolated from Palhinhaea cernua. The structure and absolute configuration of 1 were elucidated by a combination of NMR spectra, optical rotation calculation, and X-ray diffraction experiment. A possible biogenetic pathway was also proposed.

Lycospidine A (1), the first example of a Lycopodium alkaloid which contains an unprecedented five-membered A ring, was isolated from Lycopodium complanatum. The unique five-membered A ring in 1 indicates that carbons 2-5 in 1 are presumably derived from proline instead of the lysine biosynthetically, which suggests that 1 represent a new class of Lycopodium alkaloid. In addition, the unique structural feature and biosynthetic origin of 1 shed new insight into the structural diversity of Lycopodium alkaloid analogue libraries potentially accessible by engineered biosynthesis.