Soil bacterial hydrolysis leading to genuine aglycone—IX : A steroidal prosapogenol of new type from epigeous part of Metanarthecium luteo-viride maxim. and characterization of 3-epi-metagenin

By virtue of the soil bacterial hydrolysis method, a mixture (ca 12:1) of prosapogenols has been isolated, and on the basis of chemical and physicochemical evidence, the structure of major component (designated as NE-1A) has been established as 2β - acetoxy - 3α - hydroxy - 11α- (tri -O- acetyl - α - L - arabinopyranosyl)oxy - 5β, 25R - spirostane (10), and the minor presumed as its 3-epimer (11). NE-1A (10) is characteristic of possessing a fully acetylated arabinoside linkage at C-11 of a new steroidal aglycone 3-epi-metagenin (9), which is a ninth spirostanol isolated from the titled plant.Finally, NE-1A (10) has been subjected to detailed PMR examinations including homonuclear INDOR, double and triple resonance experiments, and the prominent signals have been assigned.     

Soil bacterial hydrolysis leading to genuine aglycone—VIII : Structures of a genuine sapogenol protobassic acid and a prosapogenol of seed kernels of Madhuca longifolia L.

By virtue of the soil bacterial hydrolysis method, a genuine sapogenol named protobassic acid was obtained from the saponins of seed kernels of Madhuca longifolia L. (Sapotaceae), and the structure has been established as 2β, 3β, 6β, 23-tetrahydroxy-olean-12-en-28-oic acid (2a). In addition, the structure of a prosapogenol designated as Mi-glycoside I, which was isolated concurrently during the above microbiological procedure, has been elucidated as 3-0-β-d-glucopyranosyl-protobassic acid (3a). It has been suggested that protobassic acid (2a) may be a common sapogenol of several sapotaceous plants in place of hitherto approved bassic acid (1a).     

Studies on the constituents of bocconia cordata. III Structure elucidation of bocconine by means of nuclear magnetic resonance spectroscopic studies

The nmr spectroscopic studies on methoxybocconine are described. The spectral data indicate bocconine to be 2,3,7,8-bis(methylenedioxy)-10-methoxy-5-methylbenzo[c]phenanthridine.     

Resin glycosides. I. isolation and structure elucidation of orizabin-I. II. IlI and IV,genuine resin glycosides from the root of Ipomoea orizabensis

Four compounds named orizabin I, II, III and IV, which are ether-soluble and correspond to the so-called resin glycoside “jalapin” were isolated, for the first time, from the root of Ipomoea orizabensis (Convoi vul aceae). Unlike the presumption advocated by Mannich and Schumann for the ether-insoluble glycoside “convoivulin” from I. purgá, all of them were respectively a monomer of hydroxyfatty acid oligoglycoside in which the sugar moiety is partially acylated by organic acids and also combines with the car☐y group of the aglycone to form a macrocyclic ester. Their isolation in a pure state was successfully achieved by a high resolution preparative HPLC in the final step. The structures were determined on the basis of chemical and spectral data and regarded to represent those of genuine ingredients.     

Bioactive marine metabolites VI. Structure elucidation of discodermin a,an antimicrobial peptide from the marine sponge Discodermia kiiensis

The structure of an antimicrobial peptide discodermin A isolated from the marine sponge Discodermia kiiensis has been elucidated as CHO-d-Ala-l-Phe-d-Pro-d-t-Leu-l-t-Leu-d-Trp-l-Arg-d-Cys(O₃H)-l-T$\text{hr-}\text{l}\text{-MeGln-}\text{d}\text{-Leu-}\text{l}\text{-Asn-}\text{l}\text{-Thr-Sar}$.     

Precipitation of magnesium ammonium phosphate from homogeneous solution by means of hydrolysis of p-nitrophenylphosphate with an alkaline phosphatase

In the precipitation of magnesium ammonium phosphate from homogeneous solution, phosphate ions were generated by means of hydrolysis of p-nitrophenylphosphate with an alkaline phosphatase. Conditions for the gravimetric determination of magnesium ion as magnesium ammonium phosphate hexahydrate were investigated.     

CompX,a luciferin-related tyrosine derivative from the bioluminescent earthworm Fridericia heliota. Structure elucidation and total synthesis

A luciferin analog, CompX, was isolated from the extracts of the bioluminescent earthworm Fridericia heliota. Its structure was determined as (Z)-5-(2-carboxy-2-methoxyvinyl)-2-hydroxybenzoic acid by spectroscopic data analysis and was confirmed by total synthesis. The (Z)-configuration of the double bond was established by comparing the ROESY spectra of CompX with those of its synthetic (E)-isomer. CompX represents a tyrosine analog, not previously found in natural sources, and is probably derived from tyrosine by deamination, O-methylation of the resulting alpha-keto acid, and carboxylation at the aromatic core.     

Structure elucidation of a novel family of mycolactone toxins from the frog pathogen Mycobacterium sp. MU128FXT by mass spectrometry

Structures are proposed, based on LC-ion trap MSn analysis and high-resolution FTICR MS/MS analysis, for a novel family of mycolactone toxins isolated from the frog pathogen MU128FXT and differing from those produced by the human pathogen M. ulcerans MUAgy99 in having an altered polyketide side chain.     

On the mechanism of hydrolysis of the triazolobenzodiazepine,triazolam. Spectroscopic study

The hydrolysis of 8-chloro-6-(2′-chlorophenyl)-1-methyl-4H[1,2,4]triazolo[4,3-a][1,4]benzodiazepine (Triazolam) at room temperature, involves a reversible mechanism. The intermediate is a protonated species and the final product is the ring-opened compound resulting from the reversible scission of the imine bond. The two compounds were determined simultaneously as a function of pH with pmr and cmr spectrometry. Spectral data of the benzophenone derivative II (ir, cmr, pmr) are reported.     

Structure elucidation of two new unusual monoterpene glycosides from Euphorbia decipiens, by 1D and 2D NMR experiments

Two new unusual monoterpene glycosides, (Z)-3,6-dimethyl-3-(β-D-O-glucosylmethylene)cyclohept-4-ene-1-one (1) and 3,6-dimethyl-3-(β-D-O-glucosylmethylene)cycloheptanone (2) have been isolated along with five known compounds, 3-hydroxy-4-methoxybenzoic acid, 6,7-dihydroxycoumarin, luteolin, apigenin 5-O-αl-L-rhamnoside, and pinocembrin-7-O-rutinoside from ethyl acetate extract of Euphorbia decipiens. The structures of the isolated compounds were elucidated by extensive 1D- and 2D-NMR, and mass spectroscopic analyses.     

Structure elucidation of cresylviolet perchlorate in polyvinylbutyral by the joint application of IR, FTIR, Raman, UV and visible spectroscopy

Infrared, Fourier transform infrared, Raman, UV absorption and emission spectra of cresylviolet perchlorate (CV) in polyvinylbutyral (PVB) were recorded in the region 1250-4000 cm(-1) at room temperature and assignments have been made for the observed absorption emission and Raman scattered lines.     

Structure elucidation of two new xanthone derivatives from the marine fungus Penicillium sp. (ZZF 32#) from the South China Sea

Two new xanthones, 8-(methoxycarbonyl)-1-hydroxy-9-oxo-9H-xanthene-3-carboxylic acid (1) and dimethyl 8-methoxy-9-oxo-9H-xanthene-1,6-dicarboxylate (2) and one known xanthone methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (3) were isolated from the culture broth of the mangrove fungus Penicillium sp. (ZZF 32#) collected from the South China Sea. Their structures were established by comprehensive analysis of one-dimensional (1D) and two-dimensional (2D) NMR data. The structure of compound 3 was confirmed by X-ray crystallography, which led to the suggestion that janthinone (4) might have the same structure as 3. Compounds 1-3 were inactive against KB or KBv200 cells during cytotoxicity evaluations.     

New tricyclic and tetracyclic pyranocoumarins with an unprecedented C‐4 substituent. Structure elucidation of tamanolide,tamanolide D and tamanolide P from Calophyllum inophyllum of French Polynesia

Three new pyranocoumarin derivatives, tamanolide (1), tamanolide D (2) and tamanolide P (3), were isolated from the almond seeds of Calophyllum inophyllum L. (Clusiaceae) grown in French Polynesia. These compounds, having an unprecedented C‐4 isobutyl substituent, have been characterized as a new class of pyranocoumarins called tamanolides. Their structures were elucidated on the basis of 1D and 2D NMR techniques (COSY, NOESY, HSQC and HMBC) in association with MS (HR‐ESI‐MS) data analysis. Copyright © 2009 John Wiley & Sons, Ltd.