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by Jian-Guang Luo, Hong Yin, Bo-Yi Fan, and Ling-Yi Kong*State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry,China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, P. R. China(phone/fax: þ86-25-83271405; e-mail: cpu_lykong@126.com)A rare labdane diterpene g-lactam, 1, and two new labdane diterpenoids, 2 and 3, along with twoknown diterpenes, 4 and 5, were isolated from the roots of Amomum maximum. Their structures wereestablished on the basis of spectroscopic data. All of the isolates were evaluated for their cytotoxicactivities, and compound 3 was found to exhibit an inhibitory activity against MG-63 cell lines with anIC

Two new Lycopodium alkaloids, (+)-cermizine D N-oxide (1) and (8β)-8-(acetyloxy)obscurumine A (2), along with five known compounds, were isolated from the crude alkaloid portion of Lycopodium obscurum. Their structures were elucidated on the basis of spectroscopic data and chemical correlation. All of these alkaloids were tested in an assay for acetylcholine esterase (AChE) inhibitory activity.

The three new 3-O-methylquercetin glucosides 1–3, together with three known congeners and 3-O-methylquercetin, were isolated from the fern Ophioglossum pedunculosum (quercetin=2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one). The new compounds were identified on the basis of spectroscopic analysis as 5′-isoprenyl-3-O-methylquercetin 4′,7-di-β-D-glucopyranoside (1), 3-O-methylquercetin 4′-β-D-glucopyranoside 7-[O-β-D-glucopyranosyl-(12)-β-D-glucopyranoside] (2), and 3-O-methylquercetin 7-[O-β-D-glucopyranosyl-(12)-β-D-glucopyranoside] (3). The effect of the isolated compounds on lipopolysaccharide (LPS)-induced NO production was evaluated. The inhibitory activity of 3-O-methylquercetin derivatives decreased markedly with the increasing number of glucosyl groups in the structures.

Five new β-carboline-type alkaloids, dichotomines F–J (1–5, resp.), along with nine known compounds, dichotomides I, III, V, and VII (6–9, resp.), stellarines A and C (10–11, resp.), dichotomine B (12), glucodichotomine B (13), and 1-acetyl-3-carboxy-β-carboline (14), were isolated from the roots of Chinese medicinal plant Stellaria dichotoma L. var. lanceolata. Their structures were determined by chemical and spectroscopic means. Compounds 12 and 13 exhibited moderate cytotoxicity.

The seven new triterpenoid saponins 1–7 were isolated from the roots of Gypsophila paniculata L. Their structures were established by 1D- and 2D-NMR techniques, HR-MS, and acid hydrolysis. The isolated compounds include 3,28-O-bidesmosides with or without a 4-methoxycinnamoyl group (see 1vs.2 and 3), and 3-O-monoglucosides 4–7. All isolated saponins 1–7 and their aglycones were evaluated for their α-glucosidase inhibition activity. Compound 1 showed inhibitory activity against yeast α-glucosidase with an IC50 value of 100.9±3.3 μM, whereas compounds 2–7 were inactive.

A pair of new oleanane-type nortriterpene saponin epimers, neogypsoside A (1) and B (2) (Fig. 1) with neogypsogenin A (3) and neogypsogenin B (4) as the two new aglycons, as well as the two known triterpene saponins 5 and 6(Fig. 1), were isolated from the roots of Gypsophila oldhamiana. Their structures were determined by analysis of their NMR data. A possible biogenetic pathway to the nortriterpene saponins 1 and 2 is proposed (Scheme 2).