New glycosylsphingolipids from Psychotria serpens L.

In clinical, Psychotria serpens L. was often substitute for Caulis trachelospermi to treat cancer in China. Meanwhile, EtOAc and n-BuOH fractions of MeOH extract of P. serpens L. show power activity against H460, HepG2, Hela, and PC9/GR cell lines, and no toxic effects against normal 16HBE cell lines. In our ongoing search for bioactive novel compounds from Chinese material medica, one new type of glycosylsphingolipids Psychotramide (1a-1c) were isolated from P. serpens L., and their structures were identified through spectroscopic techniques including NMR (1D and 2D) and MS (LC-MS, and GC-MS).

Bioactive triterpenoids from the leaves of Eriobotrya japonica as the natural PDE4 inhibitors.

The ethanolic extract of the leaves of Eriobotrya japonica exhibited inhibitory activity against phosphodiesterase-4D (PDE4D), which is a therapeutic target of inflammatory disease. Subsequent bioassay-guided fractionation led to the isolation of a new triterpene (1), together with seven known triterpenoids, methyl corosolate (2), ursolic acid (3), oleanolic acid (4), methyl maslinate (5), α-amyin (6), 3ß,19α,23-trihydroxy-urs-12-ene (7) and uvaol (8). The structure of compound 1 was established as 3ß-hydroxyl-21ß-acetoxyl-urs-12-en-28-carboxylate on the basis of interpretation of its 1D and 2D NMR and HR-ESI-MS spectroscopic data. The bioassay results verified compounds 2, 3 and 8 inhibited PDE4D2 effectively with the IC50 values of 3.06, 2.18 and 5.17 µM, respectively, which may provide a novel mechanism for the anti-inflammatory activity of the leaves of E. japonica.

New cyclic tetrapeptide from the coral-derived endophytic bacteria Brevibacterium sp. L-4 collected from the South China Sea.

One new cyclic tetrapeptide cyclic-(Tyr-Ala-Leu-Ser) (1) along with four natural compounds firstly obtained 3H-imidazole-4-carboxylic acid (2), 2-methyl-3H-imidazole-4-carboxylic acid (3), 3-ethylidene-6-isopropyl-piperazine-2,5-dione (4), and 3-isobutylidene-6-methyl piperazine-2,5-dione (5) have been isolated from the coral derived endophytic bacteria Brevibacterium sp. L-4 collected from the South China Sea. Their structures were elucidated through spectroscopic techniques including NMR (1D and 2D), MS, and EA, and their relative configurations were also assigned by NMR analysis.

Pelopuradazole, a new imidazole derivative alkaloid from the marine bacteria Pelomonas puraquae sp. nov.

One new imidazole derivative alkaloid pelopuradazole (1), together with three known alkaloids as in 3H-imidazole-4-carboxylic acid (2), 1H-pyrrole-2-carboxylic acid (3) and 2-methyl-3H-imidazole-4-carboxylic acid (4) and two known cyclo-dipeptides pelopurin A (5) and pelopurin B (6), has been isolated from the marine bacterium Pelomonas puraquae sp. nov. Pelopuradazole (1) was a new imidazole derivative alkaloid, while compounds 2, 3, 5 and 6 were firstly obtained as natural products. Compounds 1-6 were isolated from P. puraquae sp. nov. for the first time.

Successful micropropagation of the cadmium hyperaccumulator Viola baoshanensis (Violaceae).

Viola baoshanensis is one of the most rare cadmium (Cd) hyperaccumulators, however, it is hard to propagate. Micropropagation has been applied to solve the problems with propagation of a few heavy metal hyperaccumulators. Therefore there is a high likelihood that micropropagation may offer a suitable method for large-scale propagation of V. baoshanensis To test this hypothesis, three types of explants were used for shoot regeneration and various combinations of four plant growth regulators were used to improve shoot regeneration efficiency from leaflet of V. baoshanensis. Best shoot regeneration efficiency was obtained by incubating leaflet in a 1/2 MS medium supplemented with 2.5 oM BA + 2.5 microM IBA, therein shoot regeneration rate was 70.9% and the number of shoots formation per explant was 22.4. Rooting was achieved from almost all regenerated shoot growing on 1/2 MS medium without plant growth regulator. Micropropagated seedlings were acclimatized under greenhouse conditions and 95% of them survived and showed no visible morphological variation compared to their donor plant. Furthermore, there were no significant differences between regenerated and seed-germinated V. baoshanensis in Cd tolerance and accumulation. These results suggested that an efficient and rapid micropropogation system was successfully developed for V. baoshanensis.

Lactones from a brown alga endophytic fungus (No. ZZF36) from the South China Sea and their antimicrobial activities.

Two new metabolites named 6-oxo-de-O-methyllasiodiplodin (1) and (E)-9-etheno-lasiodiplodin (2), with three known compounds lasiodiplodin (3), de-O-methyllasiodiplodin (4), and 5-hydroxy-de-O-methyllasiodiplodin (5), were isolated from the mycelium extracts of a brown alga endophytic fungus (No. ZZF36) obtained from the South China Sea. Their structures were elucidated using spectroscopic methods, mainly 1D and 2D NMR. Additionally, the structure of compound 1 was confirmed by single crystal X-ray diffraction analysis. The antimicrobial activities of lasiodiplodins, and the 13-acetyl and 12,14-dibromo derivatives of lasiodiplodin were tested for the first time and the results were compared to each other.

[Study on the sterols from a brown alga endophytic fungus (NO. ZZF36) from the South China Sea].

Four sterols were isolated from a brown alga endophytic fungus NO. ZZF36 from the South China Sea. Their structures were identified as brassicaterol(2), ergosterol(2), ergosterol peroxide(3),7,22(E)-ergostadiene-beta,5alpha,6beta-triol(4) by spectroscopic methods.