Three new compounds from soil actinomycete Streptomyces albospinus 15-4-2

Three new compounds, 2-methyl-2,5,6-bornantriol (1), 4,4′-(3-hydroxypropane-1,1-diyl)diphenol (2), and 7-(4-methoxybenzyl)-4,5,6,7-tetrahydro-1,3-oxazepine-5,6-diol (3), were isolated from the fermentation broth of the soil actinomycete Streptomyces albospinus 15-4-2. Their structures were completely elucidated using the combination of 1D, 2D NMR techniques (COSY, HMQC, HMBC, and ROESY), and HR-ESI-MS analysis. None of the compounds 1–3 showed any inhibitory effect on Fusarium oxysporum f.sp. cubense race 4.     

Two new dolabranes from the Chinese mangrove Ceriops tagal

Two new dolabranes, named tagalsins V–W (1–2), were isolated from the aerial parts of Ceriops tagal, together with 10 known terpenes (3–12). The structures of these compounds were determined on the basis of extensive spectroscopic data or comparison with data in the literature (known compounds).     

Limonoids from the fruits of Cipadessa cinerascens

A new limonoid, 3-de(2-methylbutanoyl)-3-propanoylcipadesin (1), along with 10 known limonoids and 1 known triterpenoid, was isolated from the fruits of Cipadessa cinerascens. Their structures were elucidated on the basis of spectroscopic analysis. All compounds were evaluated for their antimicrobial activities, and compounds 6 and 12 showed weak antimicrobial activities against MRSA 82^# and MRSA 92^#.     

Chemical constituents of Isodon nervosus and their cytotoxicity

Two new ent-kaurane diterpenoids, 6,20,15α-trihydroxy-6,7-seco-1α,7-olide-ent-kaur-16-ene (1) and 7β,12α-dihydroxy-6β,15β-diacetoxy-7α,20-epoxy-ent-kaur-2,16-dien-1-one (2), together with the six known compounds, were isolated from the aerial part of Isodon nervosus. The structures of the new compounds were determined by spectral methods (1D, 2D NMR, and MS). Six compounds were assayed for their cytotoxicity against HL60, SMMC-7721, and HeLa human cell lines. Compounds 5, 7, and 8 showed significant cytotoxicity.     

Two new lignan glycosides from the fruits of Pyrus ussuriensis

Two new lignan glycosides, ussuriensislignan A (1) and ussuriensislignan B (2), together with seventeen known compounds (3–19), were isolated from the fruits of Pyrus ussuriensis. Their structures were determined by various spectroscopic methods. This is the first report of the isolation of lignans (compounds 1–3) from the genus Pyrus, and compounds 3–6, 12–16 were reported from Pyrus for the first time.     

Chemical constituents from Dendrobium hainanense

A new phenolic derivative (1) and a new dihydrophenanthrene (2) were isolated from the aerial part of Dendrobium hainanense rofe, along with 12 known compounds. The structures of the new compounds were elucidated by spectroscopic analysis，and the relative configuration of compound 1 was determined by J-based configuration analysis (JBCA) method. Bioassay result indicated that compound 1 exhibited weak antibacterial activity against Canidia albicans and Ralstonia solanaceanum.     

Three new drimane sesquiterpenoids from cultures of the fungus Penicillium sp.

Three new drimane sesquiterpenoids, 12-hydroxyalbrassitriol (1), drim-8(12)-en-6β,7α, 9α,11-tetraol (2), and drim-68(12)-dien-9α,11-diol (3), along with one known analog albrassitriol (4), were isolated from cultures of the tin mine tailings-associated fungus Penicillium sp. The new structures were determined on the basis of extensive spectroscopic analyses. All compounds were tested for their cytotoxicities against five human cancer cell lines.     

A New Triterpenoid from Stelmatocrypton khasianum

Abstract

A new triterpenoid, 2α-,3β-,19α-trihydroxy-urs-12-ene-24,28-dioic acid (1), along with two known compounds, 3β-acetoxy-urs-12-ene-11-one (2) and vomifoliol (3), was isolated from stems of Stelmatocrypton khasianum for the first time. Their structures were elucidated on the basis of chemical and spectroscopic methods.     

Two new dammarane monodesmosides from Centella asiatica

Two new dammarane monodesmosides centellosides A (1) and B (2), and two new natural products ginsenosides Mc (10) and Y (11), together with 11 known compounds (3–9 and 12–15) reported for the first time from this genus, were isolated from the whole plants of Centella asiatica. All structures were elucidated by spectroscopic techniques and chemical methods, and compared with literature values. All the isolated compounds were evaluated in vitro for cytotoxicity.     

Two new metabolites from Daldinia eschscholtzii,an endophytic fungus derived from Pogostemon cablin

The chemical investigation of the mycelia of endophytic fungus Daldinia eschscholtzii A630, which was isolated from the medicinal plant Pogostemon cablin, resulted in the isolation of two new compounds, named eschscholin A (1), 3-ene-2-methyl-2H-1-benzopyran-5-ol (2), and one new natural product 3,5-dihydroxy-2-methyl-4H-chromen-4-one (3), along with seven known compounds. Their structures were fully characterized by means of detailed spectroscopic analysis, and in comparison with published data for known compounds. All of the isolated compounds (1–10) were evaluated for their antibacterial activities.