Jun-Jie Tan

Glycosidic constituents from the roots and rhizomes of Melicope pteleifolia.

Seven new diglycosidic constituents, named pteleifosides A-G (1-7), along with ten known glycosides, were isolated from the roots and rhizomes of Melicope pteleifolia (Champ. ex Benth.) T. Hartley. The structures of the isolated compounds were established on the basis of chemical and spectroscopic methods, mainly 1D and 2D NMR data and mass spectrometry.

Lamiolactone, a new iridoid lactone from Lamiophlomis rotata.

Lamiolactone (1), a new iridoid lactone, together with five known iridoids, were isolated from the 95% EtOH extract of the roots of Lamiophlomis rotata. The structure of 1 was elucidated to be methyl antirrhinolide-4-carboxylate on the basis of spectroscopic analysis.

Two new N-oxide Lycopodium alkaloids from Huperzia serrata

Two new Lycopodium alkaloids, N-oxidehuperzine E (1) and N-oxidehuperzine F (2), along with two known alkaloids, huperzines E (3) and F (4), were isolated from Huperzia serrata (Thunb.) Trev. Their structures were elucidated by spectroscopic and chemical transformations.

Arylnaphthalene lignan glycosides and other constituents from Phyllanthus reticulatus

Two new arylnaphthalene lignan glycosides, named reticulatusides A (1) and B (2), together with eight known compounds were isolated from the 95% EtOH extract of the whole plant of Phyllanthus reticulatus. The structures of the new compounds were elucidated by spectroscopic methods.

Lycopodium alkaloids from Huperzia serrata.

A new lycopodane-type Lycopodium alkaloid, 6α-hydroxy-5,15-oxide-lycopodane (1), and seven known alkaloids were isolated from the whole plants of Huperzia serrata. Their structures were elucidated by means of spectroscopic methods. 12-Deoxyhuperzine O (2) was reported as a naturally occurring alkaloid for the first time, and showed an antagonist effect on the N-methyl-d-aspartate receptor with an IC50 value of 0.92 μM.

Triterpenoids from the barks of Terminalia chebula

Two new triterpenoids, termichebuloside A (1), an unusual dimeric triterpenoid saponin, and termichebulolide (2), an oleanolic acid-type lactone, along with 11 known triterpenoids, were isolated from MeOH extract of the barks of Terminalia chebula. The structures of 1 and 2 were elucidated to be arjunglucoside I-(3-O-19′,23-O-19′)-18,19-seco-19-hydroxyarjunglucoside I (1) and 2α,3β,23-trihydroxyolean-11,13(18)-dien-28,19β-olide (2), respectively, on the basis of spectroscopic evidences and biogenetic consideration.

Minor dammarane saponins from the hongshen extract of Shenmai injection.

A new dammarane-type triterpenoid saponin, (20R)-ginsenoside ST2 (1), along with five known saponins was isolated from the hongshen extract of Shenmai injection. The structure of 1 was elucidated to be (20R)-dammar-23(E)-ene-3β,6α,12β,20,25-pentol 6-O-β-d-glucopyranoside by means of spectroscopic methods.

The resolution of aglinin A epimers and their NMR assignments

Aglinin A (1) is a mixture of C24-epimeric 20S,24-epoxy-24,25-dihydroxy-3,4-secodammar-4(28)-en-3-oic acid and present in plants of the family Meliaceae. The two epimers of 1 were resolved through an acetonide reaction, and the absolute configurations of two derivatives were deduced by the analysis of their 13C NMR differences induced by γ-gauche or steric effect. Based on it, the 13C NMR assignment of 24R-1 and 24S-1 was also established.