Fusarihexins A and B: Novel Cyclic Hexadepsipeptides from the Mangrove Endophytic Fungus Fusarium sp. R5 with Antifungal Activities.

Two novel cyclic hexadepsipeptides, fusarihexin A (1: ) and fusarihexin B (2: ), and two known compounds, cyclo-(L-Leu-L-Leu-D-Leu-L-Leu-L-Val) (3: ) and cyclo-(L-Leu-L-Leu-D-Leu-L-Leu-L-Ile) (4: ), were isolated from the marine mangrove endophytic fungus Fusarium sp. R5. Their chemical structures were elucidated on the basis of spectroscopic data and Marfey's analysis. In an in vitro bioassay, fusarihexin A (1: ) remarkably inhibited three plant pathogenic fungi: Colletotrichum gloeosporioides (Penz.) Sacc., which causes anthracnose in many fruits and vegetables, Colletotrichum musae (Berk. and M. A. Curtis) Arx, which causes crown rot and anthracnose in bananas, and Fusarium oxysporum Schlecht. f. sp. lycopersici (Sacc.) W. C. Snyder et H. N. Hansen, which causes Fusarium wilt and fruit rot in tomatoes. Fusarihexin B (2: ) strongly inhibited C. gloeosporioides and C. musae. The compounds were more potent than carbendazim, which is widely used as an agricultural and horticultural fungicide worldwide.

Immunomodulation of human T cell responses with receptor selective enkephalins.

The delta-opioid receptor selective [2-D-penicillamine-5-D-penicillamine] enkephalin (DPDPE) and the mu receptor selective Tyr-D-Orn-Phe-Asp-NH2 (TOPA) were found respectively, to have marked immunostimulant and immunosuppressant activities in both normal subjects and patients suffering from leprosy and tuberculosis. Antigen specific lymphoproliferation and numbers of rosette forming T cells were significantly (P < 0.05) enhanced on in vitro treatment with Met-enkephalin. This was further increased (P < 0.001) in the presence of the delta selective DPDPE. In contrast, treatment with mu selective TOPA inhibited lymphoproliferation substantially (P < 0.01) and rosette formation to a lesser extent.