A facile approach to tryptophan derivatives for the total synthesis of argyrin analogues.

A facile route has been established for the synthesis of indole-substituted (S)-tryptophans from corresponding indoles, which utilizes a chiral auxiliary-facilitated Strecker amino acid synthesis strategy. The chiral auxiliary reagents evaluated were (S)-methylbenzylamine and related derivatives. To illustrate the robustness of the method, eight optically pure (S)-tryptophan analogues were synthesized, which were subsequently used for the convergent synthesis of a potent antibacterial agent, argyrin A and its analogues.

Biologically active constituents from the fruiting body of Taiwanofungus camphoratus.

Five new benzenoids, benzocamphorins A-E (1-5), and 10 recently isolated triterpenoids, camphoratins A-J (16-25), together with 23 known compounds including seven benzenoids (6-12), three lignans (13-15), and 13 triterpenoids (26-38) were isolated from the fruiting body of Taiwanofungus camphoratus. Their structures were established by spectroscopic analysis. Selected compounds were examined for cytotoxic and anti-inflammatory activities. Compounds 9 and 21 showed moderate cytotoxicity against MCF-7 and Hep2 cell lines with ED(50) values of 3.4 and 3.0µg/mL, respectively. Compounds 21, 25, 26, 29-31, 33, and 36 demonstrated potent anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-induced nitric oxide (NO) production with IC(50) values of 2.5, 1.6, 3.6, 0.6, 4.1, 4.2, 2.5, and 1.5µM, respectively, which were better than those of the nonspecific nitric oxide synthase (NOS) inhibitor N-nitro-l-arginine methyl ester (l-NAME) (IC(50): 25.8µM). These results may substantiate the use of T. camphoratus in traditional Chinese medicine (TCM) for the treatment of inflammation and cancer-related diseases. The newly discovered compounds deserve further development as anti-inflammatory candidates.

Camphoratins A-J, potent cytotoxic and anti-inflammatory triterpenoids from the fruiting body of Taiwanofungus camphoratus.

Ten new triterpenoids, camphoratins A-J (1-10), along with 12 known compounds were isolated from the fruiting body of Taiwanofungus camphoratus. Their structures were established by spectroscopic analysis and chemical methods. Compound 10 is the first example of a naturally occurring ergosteroid with an unusual cis-C/D ring junction. Compounds 2-6 and 11 showed moderate to potent cytotoxicity, with EC(50) values ranging from 0.3 to 3 µM against KB and KB-VIN human cancer cell lines. Compounds 6, 10, 11, 14-16, 18, and 21 exhibited anti-inflammatory NO-production inhibition activity with IC(50) values of less than 5 µM, and were more potent than the nonspecific NOS inhibitor N(ω)-nitro-L-arginine methyl ester.