Ji-Feng Luo

Palhinine A, a Novel Alkaloid from Palhinhaea cernua

Palhinine A, a novel C(16)N-type Lycopodium alkaloid with a unique 5/6/6/9 tetracyclic ring system, was isolated from the whole plant of Palhinhaea cernua L. (Lycopodiaceae). Its structure was elucidated by spectroscopic methods, and the absolute configuration was determined by single-crystal X-ray diffraction analysis using the Flack parameter. Palhinine A is reported as the first example of Lycopodium alkaloids of which C-16 is fused to a new ring through a C-16-C-4 lingkage.

Clerodane diterpenoids and prenylated flavonoids from Dodonaea viscosa

Repeated column chromatography of the EtOAc-soluble fraction of the aerial parts of Dodonaea viscosa led to the isolation of two new modified clerodanes, methyl dodovisate A (1) and methyl dodovisate B (2), two new prenylated flavonoids, 5,7,4′-trihydroxy-3′,5′-di(3-methylbut-2-enyl)-3,6-dimethoxyflavone (10) and 5,7,4′-trihydroxy-3′-(4-hydroxy-3-methylbutyl)-5′-(3-methylbut-2-enyl)-3,6-dimethoxyflavone (11), together with eight known compounds, dodonic acid (3), hautriwaic acid (4), hautriwaic lactone (5), (+)-hardwickiic acid (6), 5α-hydroxy-1,2-dehydro-5,10-dihydroprintzianic acid methyl ester (7), strictic acid (8), dodonolide (9), and aliarin (12). The structures of the new compounds were elucidated by spectroscopic data analysis. Compounds 1–9 and 11 were evaluated on larvicidal activity against the fourth-instar larvae of Aedes albopictus and Culex pipens quinquefasciatus.

Sarmentosumols A to F, New Mono- and Dimeric Alkenylphenols from Piper sarmentosum

Two new mono- and four new dimeric alkenylphenols, namely sarmentosumols A to F (1-6), were isolated from the aerial parts of Piper sarmentosum. The structures of these compounds were determined through a detailed analysis of NMR and MS data. Their antimicrobial activity against Escherichia coli, Staphyloccocus aureus, and Candida albicans, and their cytotoxic activity against human myeloid leukemia (K562) and human lung adenocarcinoma (A549) cell lines were also evaluated. Except for sarmentosumol A (1), whose MIC on S. aureus was reported to be 7.0 µg/mL, none of the other newly discovered compounds exhibited antimicrobial property. The studied compounds did not possess any cytotoxic property.

Lycopodium alkaloids from Palhinhaea cernua

Two new Lycopodium alkaloids, acetyllycoposerramine M and palcernine A were isolated from whole plant extracts of Palhinhaea cernua L. together with ten previously identified compounds. The structures of the new compounds were elucidated by spectroscopic methods and single-crystal X-ray diffraction analyses using the Flack parameter.

New amide alkaloids from Piper longum fruits

Three new amide alkaloids piperlongumamides A-C (1–3), together with 12 known ones (4–15), were isolated from the fruits of Piper longum. The structures of the new isolates were determined using spectroscopic data analyses. Cytotoxic activity of these amides against HL-60 (human leukemia), A-549 (human lung cancer), MCF-7 (human breast cancer), SMMC-7721 (human liver cancer) and SW480 (human rectal cancer) cell lines were evaluated. Piperchabamide B (11) exhibited weak inhibitory activity against HL-60 (IC50 = 21.32 μM ), A-549 (IC50 = 23.82 μM ) and MCF-7 (IC50 = 16.58 μM ) cell lines.

Substituting one Paris for another? In vitro cytotoxic and in vivo antitumor activities of Paris forrestii, a substitute of Paris polyphylla var. yunnanensis

ETHNOPHARMACOLOGICAL RELEVANCE Chong-lou (Paris polyphylla var. yunnanensis or P. polyphylla var. chinensis) is traditionally used as an anticancer medicine in China. It is also the material basis of some Chinese patent anticancer medicines, such as Gan-Fu-Le capsules, Bo-Er-Ning capsules, Lou-Lian capsules, Ruan-Jian oral liquid, and Qi-Zhen capsules. P. forrestii, a substitute for Chong-lou, is planted at a large scale in the Yunnan Province of China. AIM OF THE STUDY To clarify the active chemical constituents of P. forrestii and evaluate the in vitro and in vivo anticancer activities of the total saponins from P. forrestii. MATERIALS AND METHODS The total saponins of P. forrestii were extracted and separated to yield pure compounds by chromatographic techniques, and the structures of the isolates were elucidated by spectroscopic methods. The cytotoxicity of the crude extracts, total saponins, and chemical constituents were evaluated using an MTS assay. In vivo antitumor activities of the total saponins from P. forrestii were measured using H22 tumor-bearing mice by intraperitoneal (ip) administration. RESULTS Eight compounds, including polyphyllin D (1), formosanin C (2), dioscin (3), diosgenin-3-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (4), paris saponin H (5), pennogenin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→4)]-β-d-glucopyranoside (6), pariposide A (7), and crustecdysone (8), were isolated from the total saponins of P. forrestii. The total saponins and compounds 1-6 showed significant inhibitory activity against the growth of the HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines. The total saponins from P. forrestii had a tumor-inhibitory effect in H22 tumor-bearing mice upon ip (2.25 mg/kg dose) administration, with an inhibition rate of 42.6% compared with cisplatin (ip, 2 mg/kg dose, 53.9% inhibition rate). CONCLUSION The results support that P. forrestii could be a substitute for P. polyphylla var. yunnanensis as an anticancer medicine.

New aporphine alkaloids from the aerial parts of Piper semiimmersum

Abstract Two new aporphine alkaloids, semiimmersumines A (1) and B (2), along with 20 known compounds, were isolated from the aerial parts of Piper semiimmersum (Piperaceae). The structures of the new compounds were elucidated based on the analysis of 1D and 2D NMR, MS, and CD data. The absolute configuration of semiimmersumine A (1) was determined by single crystal X-ray diffraction analysis using anomalous dispersion with copper radiation. The effects of all compounds from the plant on rabbit platelet aggregation induced by thrombin (IIa) or PAF were also evaluated.