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Three new vermistatin derivatives, 6-demethylpenisimplicissin (1), 5′-hydroxypenisimplicissin (2), and 2′′-epihydroxydihydrovermistatin (3), along with five known vermistatin analogues, methoxyvermistatin (4), vermistatin (5), 6-demethylvermistatin (6), hydroxyvermistatin (7), and penisimplicissin (8), were isolated from the culture of the mangrove endophytic fungus Penicillium sp. HN29-3B1 from Cerbera manghas. Their structures were elucidated mainly by nuclear magnetic resonance spectroscopy. The absolute configurations of compounds 1 and 2 were deduced on the basis of circular dichroism data. The absolute structures of compounds 3 and 5 were confirmed by a single-crystal X-ray diffraction experiment using Cu Kα radiation. In the bioactivity assay, compounds 1 and 3 exhibited α-glucosidase inhibitory activity with IC50 values of 9.5 ± 1.2 and 8.0 ± 1.5 µM, respectively. The plausible biosynthetic pathways for all compounds are discussed.

Arigsugacin I (1), a new α-pyrone meroterpene, along with two known compounds, arigsugacins F (2) and territrem B (3), were isolated from the mangrove endophytic fungus Penicillium sp. sk5GW1L from Kandelia candel. Their structures were identified through mass spectrometry and NMR experiments, and the absolute configuration of compound 1 was further confirmed by low-temperature (100 K) single crystal X-ray diffraction with Cu Kα radiation. The absolute configuration of compound 2 was first reported by using X-ray copper radiation. Compounds 1–3 showed inhibitory activities against acetylcholinesterase with IC50 values of 0.64 ± 0.08 µM, 0.37 ± 0.11 µM, and 7.03 ± 0.20 nM, respectively.

Two new compounds, methyl 3-chloro-6-hydroxy-2-(4-hydroxy-2-methoxy-6-methylphenoxy)-4-methoxybenzoate (1) and (2 S,5' R,E)-7-hydroxy-4,6-dimethoxy-2-(1-methoxy-3-oxo-5-methylhex-1-enyl)-benzofuran-3(2H)-one (2), together with four known compounds, griseofulvin (3), dechlorogriseofulvin (4), bostrycin (5), and deoxybostrycin (6), were isolated from the marine endophytic fungus NIGROSPORA sp. (No. 1403) collected from the South China Sea. The structures were elucidated by spectroscopic methods, 1D, 2D NMR, and HREIMS. Compounds 5 and 6 showed moderate antitumor and moderate antimicrobial activity.

Three new dimeric naphtho- γ-pyrones, named rubasperone A ( 1), rubasperone B ( 2), and rubasperone C ( 3), together with two known compounds, rubrofusarin ( 4) and rubrofusarin B ( 5), were isolated from the mangrove endophytic fungus ASPERGILLUS TUBINGENSIS (GX1-5E). Their structures were determined by spectroscopic methods, including IR, MS, and 1D and 2D NMR. The structures of 1 and 2 were further confirmed by X-ray crystallography. In the bioactivity assays against tyrosinase and α-glucosidase, rubrofusarin ( 4) exhibited moderate tyrosinase inhibitory activity, with an IC 50 value of 65.6 μM, and rubasperone C ( 3) showed mild α-glucosidase inhibitory activity, with an IC 50 value of 97.3 μM.

Bioactivity-directed fractionation of the extract of the mangrove endophytic fungus Talaromyces sp. ZH-154, which was isolated from the stem bark of Kandelia candel (L.) Druce, Rhizophoraceae, afforded two new metabolites, 7-epiaustdiol ( 1) and 8-O-methylepiaustdiol ( 2), together with the known compounds, stemphyperylenol ( 3), skyrin ( 4), secalonic acid A ( 5), emodin ( 6), and norlichexanthone ( 7). Their structures were elucidated on the basis of spectroscopic evidences including CD, MS, and 1D, 2D NMR techniques. The absolute configuration of 1 was unequivocally determined by single-crystal X-ray diffraction. All isolated compounds were evaluated for their antimicrobial and in vitro cytotoxic activities.

Two novel compounds, 3-methoxypterolactone ( 1) and 2-amino-3,4-dihydroxy-5-methoxybenzoic acid ( 2), were isolated from leaves of Cyclocarya paliurus (Batal.) Iljinsk, together with nine known compounds: pterolactone ( 3), gallic acid ( 4), 4-hydroxy-3-methoxybenzoic acid ( 5), oleanolic acid ( 6), beta-boswellic acid ( 7), alpha-boswellic acid ( 8), beta-amyrin ( 9), beta-amyrone ( 10) and 3beta-O-trans-caffeoyl-morolic acid ( 11). The structure elucidation was based on spectroscopic methods, including two-dimensional NMR experiments ( (1)H- (1)H COSY, HMQC and HMBC). All isolated compounds were evaluated for their glycosidase and glycogen phosphorylase inhibitory activities. 2-Amino-3,4-dihydroxy-5-methoxybenzoic acid and gallic acid showed significant alpha-glucosidase and glycogen phosphorylase inhibitory activities.