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Objective This study describes the in vivo pharmacokinetics and metabolism of [14C]labeled XQ-1H in male rats. Methods XQ-1H is a methanesulfonate of XQ, 10-O-(N,N-dimethylaminoethyl)-ginkgolide B, a derivative of ginkgolide B (GB) with enhanced water solubility. Since it is very difficult to synthesize radiolabeled GB, the results obtained in this study may provide helpful insight to further ADME investigation of GB and its analogue compounds. After an i.v. administration of [14C]XQ-1H to male rats, XQ (the freebase form of XQ-1H) was extensively hydrolyzed, moderately metabolized, and mainly excreted in feces (71.5% of the dose) via the biliary route. Results The main enzyme mediated metabolic pathways were mono- and di-demthylation. Using the radiolabel form of XQ-1H, the temporal binding of XQ to red blood cells was observed. Conclusion Binding of XQ to RBCs may lower the blood's viscosity and thus provide symptomatic improvement of ischemic stroke patients.

Apremilast is a novel, orally available small molecule that specifically inhibits PDE4 and thus modulates multiple pro- and anti-inflammatory mediators, and is currently under clinical development for the treatment of psoriasis and psoriatic arthritis. The pharmacokinetics and disposition of [(14)C]apremilast was investigated following a single oral dose (20 mg, 100 μCi) to healthy male subjects. Approximately 58% of the radioactive dose was excreted in urine, while faeces contained 39%. Mean C(max), AUC(0-∞) and t(max) values for apremilast in plasma were 333 ng/mL, 1970 ng*h/mL and 1.5 h. Apremilast was extensively metabolized via multiple pathways, with unchanged drug representing 45% of the circulating radioactivity and7% of the excreted radioactivity. The predominant metabolite was O-desmethyl apremilast glucuronide, representing 39% of plasma radioactivity and 34% of excreted radioactivity. The only other radioactive components that represented4% of the excreted radioactivity were O-demethylated apremilast and its hydrolysis product. Additional minor circulating and excreted compounds were formed via O-demethylation, O-deethylation, N-deacetylation, hydroxylation, glucuronidation and/or hydrolysis. The major metabolites were at least 50-fold less pharmacologically active than apremilast. Metabolic clearance of apremilast was the major route of elimination, while non-enzymatic hydrolysis and excretion of unchanged drug were involved to a lesser extent.

The lipophilicity and solubility profiles of bis(12)-hupyridone (B12H) and bis(7)-tacrine (B7T), two novel acetylcholinesterase inhibitors dimerized from huperzine A fragments and tacrine, respectively, were investigated over a broad pH range. Lipophilicity was assessed by both shake flask method with 1-octanol-water system and a reverse-phase HPLC system with methanol-water as mobile phase. The former method was used for determining the lipophilicities of the ionized forms (log D) of the dimers while the latter method was used for that of the neutral forms (log P). The log P values for B12H and B7T were found to be 5.4 and 8.2, respectively, indicating that the two dimers are highly lipophilic. The solubilities of both dimers were found to be affected by pH. The solubility of B12H was1.41 mg/ml when the pH was7, but0.06 mg/ml when the pH was8. The solubility of B7T was0.26 mg/ml when the pH was9, but0.005 mg/ml when the pH was12. The ionic strength of a solution could affect the solubilities considerably (11.16 mg/ml for B12H and 12.71 mg/ml for B7T in water; 2.07 mg/ml for B12H and 0.36 mg/ml for B7T in saline). The ionization constants (pK(a)) of the two dimers were determined by UV spectrophotometry. Both dimers were found to have two pK(a) values: 7.5+/-0.1 (pK(a1)) and 10.0+/-0.2 (pK(a2)) for B12H; and 8.7+/-0.1 (pK(a1)) and 10.7+/-0.4 (pK(a2)) for B7T. Furthermore, an in vivo pharmacological assay conducted in mice showed that a maximum AChE inhibition occurred 15 min after the single-dose and intraperitoneal administration of either dimer. This indicates that the two dimers may easily cross the blood-brain barrier. In summary, these physiochemical characteristics suggest that the two dimers may be promising candidates for the development of better drugs for Alzheimer's disease.

An analytical method using on-line high performance liquid chromatography-tandem mass spectrometry with electrospray ionization was developed and applied for the quantification of bis(7)-tacrine (B7T) in rat blood. B7T and pimozide (internal standard, IS) were extracted in a single step from 100 microl of alkalized blood with ethyl acetate. Analytes were separated using an Extend C-18 column at 25 degrees C. The elution was achieved isocratically with a mobile phase composed of 0.05% aqueous formic acid and acetonitrile (60:40, v/v) at a flow rate of 0.35 ml/min. Quantification was achieved by monitoring the selected ions at m/z 247 for B7T and m/z 462-->m/z 328 for pimozide. Retention times were 1.45 and 2.23 min for B7T and IS, respectively. Calibration curves were linear in the range from 86.4 to 2160.0 ng/ml. The established method is rapid, selective and sensitive for the identification and quantification of B7T in biological samples. The assay is accurate (bias

Some compounds readily form [M+46]+ adduct ions during positive ion electrospray ionization mass spectrometry ((+)ESI-MS) analysis. These [M+46]+ ions were characterized as [M+CH3CH2NH2+H]+ by accurate mass determination. Ethylamine involved in the adduct was proposed to be the reduction product of acetonitrile and this was confirmed using deuterated acetonitrile. Other nitrile-containing compounds tested, including isobutyronitrile and benzonitrile, also formed the adduct ions of the respective amine forms under (+)ESI-MS conditions. Hydrogen/deuterium exchange experiments demonstrated that the reductive hydrogen originated from water. Reduction of nitriles (R-CN) to their respective amines (R-CH2NH2) under (+)ESI-MS conditions expands the ability to identify nitrile-containing chemical unknowns.

A quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was established for the quality control of the Annonaceous acetogenins in the extracts of the paw paw tree, Asimina triloba (L.) Dunal. (Annonaceae). A new calibration method was developed by (a) using the diastereoisomers of analytes present in the same extract as internal standards, and (b) adding five different levels of pure analytes to the extract solutions to construct a calibration curve. These modifications completely eliminate the matrix and instrument variations and, thus, provide high accuracy. As an example, concentrations of the three major and most active Annonaceous acetogenins, bullatacin (1), asimicin (2) and trilobacin (3), were directly evaluated, without any further sample preparation, in crude dichloromethane extracts of twigs collected monthly from a single paw paw tree. The results showed that the contents of 1 and the mixture of 2 and 3 increased significantly in May and June, with 1 at 12.94 and 14.55 ppm, respectively, and the mixture of 2 and 3 at 47.05 and 51.26 ppm, respectively. The quantified contents of these potent acetogenins showed a good correlation with potencies observed in the brine shrimp test (BST), which demonstrated the highest activities with extracts from the May and June samples. These results suggest that May and June are the best time to collect paw paw twigs for maximizing pesticidal and other bioactivities. In addition, the results obtained from both methods, BST and LC/MS/MS, also verify the accuracy of each other, This well-defined LC/MS/MS method can be widely applied in the quantitative analysis of other natural components in crude extracts. Copyright © 1999 John Wiley & Sons, Ltd.

Reversed-phase high-performance liquid chromatography (RP-HPLC) fractionation, monitored by liquid chromatography/electrospray mass spectrometry (LC/ESI-MS), led to the isolation of two new bioactive annonaceous acetogenins, rollidecin C (1) and rollidecin D (2), from the bioactive aqueous methanol fraction of the leaves of Rollinia mucosa (Annonaceae). The structures were confirmed by analyses of the 1H and 13C NMR data. In addition, a known adjacent bis-tetrahydrofuran (THF) acetogenin, desacetyluvaricin (3), was isolated from this plant for the first time utilizing the LC/ESI-MS monitoring approach. Compound 1 exhibited selective cytotoxicity toward the colon tumor cell line (HT-29), while 2 showed only borderline cytotoxicity in a panel of six human tumor cell lines.

Bioactivity-directed fractionation of the seeds of Annona muricata L. (Annonaceae) resulted in the isolation of five new compounds: cis-annonacin (1), cis-annonacin-10-one (2), cis-goniothalamicin (3), arianacin (4), and javoricin (5). Three of these (1-3) are among the first cis mono-tetrahydrofuran ring acetogenins to be reported. NMR analyses of published model synthetic compounds, prepared cyclized formal acetals, and prepared Mosher ester derivatives permitted the determinations of absolute stereochemistries. Bioassays of the pure compounds, in the brine shrimp test, for the inhibition of crown gall tumors, and in a panel of human solid tumor cell lines for cytotoxicity, evaluated relative potencies. Compound 1 was selectively cytotoxic to colon adenocarcinoma cells (HT-29) in which it was 10,000 times the potency of adriamycin.

Three new bioactive Annonaceous acetogenins, asimilobin [1], cis-murisolinone [2], and trans-murisolinone [3], have been isolated from an ethanolic extract of the seeds of Asimina triloba by directing the fractionation with brine shrimp lethality. The structure were elucidated based on spectroscopic and chemical methods, In addition, cis- and trans-bullatacinone, which are known compounds, were obtained. Asimilobin [1] has adjacent bis-THF rings, located at C-10 to C-17 and having only one flanking hydroxyl group at C-18. Compounds 1-3 showed cytotoxicity values comparable with adriamycin against six human solid tumor cell lines.

Two novel bioactive acetogenins, murihexocins A (1) and B (2), were isolated from the leaves of the sour sop tree, Annona muricata (Annonaceae). 1 and 2 are C-35 mono-tetrahydrofuran (THF) acetogenins having six hydroxyls, and their structures have been elucidated by spectroscopic analyses and derivations. No Annonaceous acetogenins having six hydroxyls or with two vicinal diol groups have been reported previously. 1 and 2 showed significant inhibitory effects among six human tumor cell lines with interesting selectivities to the prostate (PC-3) and pancreatic (PACA-2) cell lines.

Trilobacin ( 1 ) is the only previously reported Annonaceous acetogenin with the erythro relative configuration between the adjacent bis-tetrahydrofuran (THF) rings. The relative configuration in the adjacent bis-THF moiety of 1 was corrected to threo/trans/erythro/cis/threo from C-15 to C-24, and the absolute configuration was determined as 4 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R and 36 S by advanced Mosher ester methodology and the COSY and NOESY spectral analyses of its 4,24-diacetate ( 1a ). Further investigation of the EtOH extract of the stem bark of the paw paw tree, Asimina triloba , monitoring for bioactivity by brine shrimp lethality, led to a novel acetogenin, trilobin ( 2 ). Spectral and chemical methods identified 2 as a 4-deoxy-10-hydroxy isomer of 1 . The absolute configuration of 2 was determined as 10 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R , and 36 S by analyses of its Mosher ester derivatives. 2 was selectively cytotoxic among three human solid tumor cell lines with over a billion times the potency of adriamycin.

Two novel bioactive mono-tetrahydrofuran (THF) γ-lactone acetogenins, 16,19-cis-murisolin (1) and murisolin A (2), were isolated from the seeds of Asimina triloba (Annonaceae) by directing the fractionation with brine shrimp lethality. 1 has a 16,19-cis mono-THF ring with two flanking hydroxyl groups and represents a new type among the natural Annonaceous acetogenins. Murisolin (3), which is new in this species, was also obtained. 1–3 showed potent and selective cytotoxicities among six human tumor cell lines.

Meliavolin ( 1 ), a new triterpene with an apotirucallane skeleton, and meliavolkin ( 2 ), a new tetranortriterpene, together with melianin A, a known compound, have been isolated from the root bark of Melia volkensii (Meliaceae) by using activity-directed fractionation with brine shrimp. The structures have been elucidated by spectral data. The relative and absolute stereochemistry of meliavolin ( 1 ) was determined by analysis of Mosher ester derivatives, 1e and 1f , and by X-ray crystallographic analysis of meliavolin diacetate, 1c. 1 and melianin A showed marginal cytotoxicities to certain human tumor cell lines, but 2 was significantly more cytotoxic, showing equivalent potency to adriamycin against the human breast tumor cell line (MCF-7).

Two new bioactive apotirucallane triterpenes, meliavolkensins A ( 1 ) and B ( 2 ), were isolated from the root bark of Melia volkensii (Meliaceae). These two compounds have a new type of substituted tetrahydropyran ring side chain, and their structures have been elucidated by spectroscopic analyses. 1 and 2 also show cytotoxic selectivities to a hyman colon tumor cell line (H-29).

Xylopien [1] and xylomatenin [2], two new bioactive monotetrahydrofuran Annonaceous acetogenins, have been isolated from an EtOH extract of the bark of Xylopia aromatica, using bioactivity-directed fractionation employing lethality to brine shrimp. These new compounds each have a double bond in the hydrocarbon chain and have been identified as C-23, C-24 dehydro analogs of xylopiacin and xylomaticin. Their structures were elucidated by spectral analyses of the parent compounds and/or simple chemical derivatives. Their absolute stereochemistries have been established by 1H- and 2D nmr experiments utilizing the production of Mosher esters. These acetogenins showed cytotoxic potencies superior to adriamycin against three human solid tumor cell lines.

A mixture of two novel cytotoxic adjacent bis-tetrahydrofuran (THF) ketolactone acetogenins, (2,4- cis and trans )-bulladecinones ( 1 and 2 ), was isolated from the bark of Annona bullata Rich. (Annonaceae). Adjacent bis-THF rings, located at C-12 and C-16 and having only one adjacent hydroxyl group, and the presence of an erythro vicinal diol in 1 and 2 are new features for the Annonaceous acetogenins.

Using lethality to brine shrimp, activity-directed fractionation of extracts of Asimina parviflora (Michx.) Dunal. (Annonaceae) has led to the isolation of two new and four known acetogenins (1–6). Compound 1, parvifloracin, is the first nonadjacent bistetrahydrofuran acetogenin with 35 carbons. Compound 2, parviflorin, is an unusual adjacent bistetrahydrofuran acetogenin with 35 carbons. Bullatacin (3), molvizarin (4), annonacin (5), and goniothalamicin (6) are also reported for the first time from this plant. Brine shrimp lethality test data and comparative cytotoxicities of 1–6 against three human solid tumor cell lines are presented.

In our continuing activity-directed search for new antitumor compounds, using brine shrimp lethality (BST), mixtures of three additional pairs (1-6) of bis-THF ketolactone acetogenins were isolated from the ethanol extract of the bark of Annona bullata Rich. (Annonaceae). Compared with (2,4-cis and trans)-bullatacinone (7 and 8), these new compounds each have one more aliphatic OH group at a different position on the hydrocarbon chain, and, thus, were named (2,4-cis and trans)-10-hydroxybullatacinone (1 and 2), (2,4-cis and trans)-12-hydroxybullatacinone (3 and 4), and (2,4-cis and trans)-29-hydroxybullataci-none (5 and 6). These mixtures all showed potent activities in the brine shrimp lethality test (BST) and exhibited cytotoxicities comparable to those of adriamycin against human solid tumor cells in culture with selectivities exhibited especially toward the breast cancer cell line (MCF-7). © 1994 wiley-Liss, Inc.

A new cytotoxic Annonaceous acetogenin, giganin (1), was isolated from the bark of Goniothalamus giganteus (Annonaceae). This compound represents a new type of Annonaceous acetogenin lacking tetrahydrofuran or epoxide rings along the aliphatic chain, and its structure was elucidated by 1H and 13C NMR, MS, COSY, and single-relayed COSY.

From Annona bullata, three more pairs of new ketolactone Annonaceous acetogenins were isolated by bioactivity-directed isolation. They are hydroxylated adjacent bistetrahydrofuran (THF) acetogenins and are named (2,4-cis and trans)-32-hydroxybullatacinone (1 and 2), (2,4-cis and trans)-31-hydroxybullatacinone (3 and 4), and (2,4-cis and trans)-30-hydroxybullatacinone (5 and 6). The structures were elucidated by analysis of the 1H- and 13C-nmr spectra of 1-6 and their acetates and the ms of their tri-trimethylsilyl (TMSi) derivatives as compared with bullatacinone [7]. This is the first time that Annonaceous acetogenins with OH groups at successive positions near the end of the aliphatic chain have been reported. All of the new compounds showed potent activities in the brine shrimp lethality test and against human solid tumor cells in culture, with selectivities exhibited especially toward the colon cancer cell line (HT-29).

The Annonaceous acetogenins are an exciting new class of bioactive natural products whose antitumour, pesticidal and other bioactivities are due to inhibition of electron transport in mitochondria. This paper tabulates the 61 compounds in this class which have been published in the period of 1990–1992 and reviews recent progress with the chemistry and biology of these potent compounds. (Appendices will be published in the next issue.)

Further bioactivity-directed fractionation of the ethanol extract of the bark of Annona bullata Rich. (Annonaceae) has led to the isolation of the new nonadjacent bis-tetrahydrofuran acetogenins, bullatanocin ( 1 ), cis- bullatanocinone ( 2 ) and trans-bullatanocinone ( 3 ). A known adjacent bis-tetrahydrofuran acetogenin, desacetyluvaricin ( 4 ), which is new to this species, was also isolated. Brine shrimp lethality test (BST) data and cytotoxicities against human solid tumor cell lines of 1–4 were compared with those of the diastereoisomers, bullatalicin ( 5 ), cis- and trans-bullatalicinone ( 6 and 7 ) and 4-deoxyasimicin ( 8 ). 1 shows cytotoxic potencies 10,000 times those of adriamycin in the lung and colon cancer cell lines.

Further bioactivity-directed fractionation of the ethanol extract of the bark of Annona bullata Rich. (Annonaceae) has led to the isolation of the new nonadjacent bis-tetrahydrofuran acetogenins, bullatanocin ( 1 ), cis- bullatanocinone ( 2 ) and trans-bullatanocinone ( 3 ). A known adjacent bis-tetrahydrofuran acetogenin, desacetyluvaricin ( 4 ), which is new to this species, was also isolated. Brine shrimp lethality test (BST) data and cytotoxicities against human solid tumor cell lines of 1–4 were compared with those of the diastereoisomers, bullatalicin ( 5 ), cis- and trans-bullatalicinone ( 6 and 7 ) and 4-deoxyasimicin ( 8 ). 1 shows cytotoxic potencies 10,000 times those of adriamycin in the lung and colon cancer cell lines.

Using lethality to brine shrimp, activity-directed fractionation of extracts of Asimina parviflora (Michx.) Dunal. (Annonaceae) has led to the isolation of two new and four known acetogenins (1–6). Compound 1, parvifloracin, is the first nonadjacent bistetrahydrofuran acetogenin with 35 carbons. Compound 2, parviflorin, is an unusual adjacent bistetrahydrofuran acetogenin with 35 carbons. Bullatacin (3), molvizarin (4), annonacin (5), and goniothalamicin (6) are also reported for the first time from this plant. Brine shrimp lethality test data and comparative cytotoxicities of 1–6 against three human solid tumor cell lines are presented.

Two new bioactive apotirucallane triterpenes, meliavolkensins A ( 1 ) and B ( 2 ), were isolated from the root bark of Melia volkensii (Meliaceae). These two compounds have a new type of substituted tetrahydropyran ring side chain, and their structures have been elucidated by spectroscopic analyses. 1 and 2 also show cytotoxic selectivities to a hyman colon tumor cell line (H-29).

Trilobacin ( 1 ) is the only previously reported Annonaceous acetogenin with the erythro relative configuration between the adjacent bis-tetrahydrofuran (THF) rings. The relative configuration in the adjacent bis-THF moiety of 1 was corrected to threo/trans/erythro/cis/threo from C-15 to C-24, and the absolute configuration was determined as 4 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R and 36 S by advanced Mosher ester methodology and the COSY and NOESY spectral analyses of its 4,24-diacetate ( 1a ). Further investigation of the EtOH extract of the stem bark of the paw paw tree, Asimina triloba , monitoring for bioactivity by brine shrimp lethality, led to a novel acetogenin, trilobin ( 2 ). Spectral and chemical methods identified 2 as a 4-deoxy-10-hydroxy isomer of 1 . The absolute configuration of 2 was determined as 10 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R , and 36 S by analyses of its Mosher ester derivatives. 2 was selectively cytotoxic among three human solid tumor cell lines with over a billion times the potency of adriamycin.

Intraperitoneal administration of CCl4 to mice led to significant increases of thiobarbituric acid-reactive substances (TBA-RS), free malondialdehyde (MDA), lipid conjugated dienes and fluorescent lipid peroxidation products in the liver. However, subchronic pretreatment with oral doses of the MeOH extract of either the underground part of Notopterygium incisum or that of N. forbesii appreciably suppressed the formation of CCl4-induced lipid peroxidation products. The suppressing potency was more remarkable in the former.

Acceleration of liquid chromatography/mass spectrometric (LC/MS) analysis for metabolite identification critically relies on effective data processing since the rate of data acquisition is much faster than the rate of data mining. The rapid and accurate identification of metabolite peaks from complex LC/MS data is a key component to speeding up the process. Current approaches routinely use selected ion chromatograms that can suffer severely from matrix effects. This paper describes a new method to automatically extract and filter metabolite-related information from LC/MS data obtained at unit mass resolution in the presence of complex biological matrices. This approach is illustrated by LC/MS analysis of the metabolites of verapamil from a rat microsome incubation spiked with biological matrix (bile). MS data were acquired in profile mode on a unit mass resolution triple-quadrupole instrument, externally calibrated using a unique procedure that corrects for both mass axis and mass spectral peak shape to facilitate metabolite identification with high mass accuracy. Through the double-filtering effects of accurate mass and isotope profile, conventional extracted ion chromatograms corresponding to the parent drug (verapamil at m/z 455), demethylated verapamil (m/z 441), and dealkylated verapamil (m/z 291), that contained substantial false-positive peaks, were simplified into chromatograms that are substantially free from matrix interferences. These filtered chromatograms approach what would have been obtained by using a radioactivity detector to detect radio-labeled metabolites of interest.

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of the powdered dried bark of Persea americana Mill. var. americana (Lauraceae) led to the isolation of one new C 20 alkyl-alkene acetonyl methyl ester designated persealide (1). Persealide showed moderate cytotoxicity against three solid tumor cell lines: human lung carcinoma (A-549), human breast carcinoma (MCF-7) and human colon adenocarcinoma (HT-29).

The Annonaceous acetogenins are amenable to analysis by liquid chromatography/mass spectrometry (LC/MS) using the electrospray positive-ion mode. Under conditions of atmospheric pressure in-source collision-induced dissociation (APICID), the acetogenins reproducibly provided characteristic ion patterns and fragment ions. Accordingly, the presence of these biologically interesting acetogenins and other derivatives in plant extracts and chromatographic fractions can be readily detected by analyzing selected ion chromatograms. LC/MS screening of a bioactive crude methanol-soluble fraction of Rollinia mucosa detected the presence of some 40 known acetogenins in this plant extract, in addition to four new acetogenins of diverse structure. This rapid and relatively uncomplicated selected ionization procedure should also prove suitable for the screening of many other structural families of natural products.

Muricatetrocin C ( 1 ), rollidecin A ( 2 ), and rollidecin B ( 3 ), three new bioactive annonaceous acetogenins bearing vicinal diols, were isolated from the leaves of Rollinia mucosa (Annonaceae) using activity-directed fractionation. The total structural elucidations of 1–3, including the absolute stereochemistries of the vicinal diols, were achieved by analyzing their per-Mosher ester derivatives. All three compounds showed potent and selective inhibitory effects against several human cancer cell lines.

The bark extracts of Annona squamosa yielded a new bioactive acetogenin, squamotacin (1), and the known compound, molvizarin (2), which is new to this species. Compound 1 is identical to the potent acetogenin, bullatacin (3), except that the adjacent bistetrahydrofuran (THF) rings and their flanking hydroxyls are shifted two carbons toward the gamma-lactone ring. Compound 1 showed cytotoxic selectively for the human prostate tumor cell line (PC-3), with a potency of over 100 million times that of Adriamycin.

Five new adjacent bis-THF annonaceous acetogenins, 32-hydroxybullatacin, 31-hydroxybullatacin, 30-hydroxybullatacin, and (2,4-cis and trans)-28-hydroxybullatacinones, were isolated from the ethanolic extract of the bark of Annona bullata Rich. (Annonaceae). The absolute configurations of the above five compounds, as well as those of (2,4-cis and trans)-32-, 31-, and 30-hydroxybullatacinones and (2,4-cis and trans)-bulladecinones, previously isolated from the same extract, were defined by the application of the advanced Mosher ester [methoxy(trifluoromethyl)phenyl acetate or MTPA] methodology. The determination of the absolute configuration of C-20 of (2,4-cis and trans)-bulladecinones to be S supports our hypothesis that the cyclization of the THF rings of (2,4-cis and trans)-bulladecinones starts from C-12 (the right side). The first five compounds listed above showed potent bioactivities in the brine shrimp lethality test (BST) and among six human solid tumour cell lines.

The leaves of Annona muricata have yielded the novel monotetrahydrofuran Annonaceous acetogenins, muricatocins A [1] and B [2]. Each compound possesses five hydroxyl groups, with two hydroxyl groups at the C-10 and C-12 positions. The absolute configurations of 1 and 2 (except for positions C-10 and C-12) were determined by Mosher ester methodology. The C-10, C-12 acetonides (1c, 2c) suggested relative stereochemistry and significantly enhanced cytotoxicity against the A-549 human lung tumor cell line. Three known monotetrahydrofuran acetogenins, annonacin A, (2,4-trans)-isoannonacin, and (2,4-cis)-isoannonacin, were also found.

The leaves of Annona muricata have yielded two additional monotetrahydrofuran Annonaceous acetogenins, annomuricin C [1] and muricatocin C [2]. Compounds 1 and 2 each possess five hydroxyl groups; two hydroxyl groups are at the C-10/C-11 and C-10/C-12 positions in 1 and 2, respectively. The absolute configurations of 1 and 2, except for positions C-10 and C-11 or C-12, were determined by Mosher ester methodology. The C-10/C-11 and C-10/C-12 acetonides (1c, 2c) suggested relative stereochemistry and significantly enhanced the cytotoxicities against the A-549 human lung and the MCF-7 human beast solid tumor cell lines. One known monotetrahydrofuran acetogenin, gigantetronenin, not described previously from this plant, was also found.

The leaves of Annona muricata have yielded eight monotetrahydrofuran Annonaceous acetogenins. Two of them, annomuricins A [1] and B [2], whose chemical structures were deduced by ms, nmr, ir, and uv spectral and chemical methods, are novel and unusual. Compounds 1 and 2 each possess five hydroxyl groups; two hydroxyl groups are vicinal, with the vicinal group of 1 threo and that of 2 erythro. The absolute configurations of 1 and 2 were determined by Mosher ester methodology. Six monotetrahydrofuran acetogenins, previously described in the seeds, were found in the leaves; these are gigantetrocin A, annonacin-10-one, muricatetrocins A and B, annonacin, and goniothalamicin.

Meliavolkenin, a new triterpene with an apotirucallane skeleton, has been isolated from the root bark of Melia volkensli (Meliaceae) by bioactivity-directed fractionation using the brine shrimp lethality test. The structure has been elucidated using spectral and chemical data. The relative stereochemistries were determined by reduction and acetonide derivations, and the ring conformations were analyzed using the results of NOESY experiments. Meliavolkenin was bioactive in the brine shrimp lethality test and gave moderate cytotoxicities against three human solid tumor lines.

Bioactive Annonaceous acetogenins have been isolated from the EtOH extract of the bark of Xylopia aromatica by bioactivity-directed fractionation using lethality to brine shrimp. These acetogenins include xylopianin [1 , xylopiacin [2], and xylomaticin [3], which are three new mono-tetrahydrofuran ring type acetogenins, in addition to the known compounds, annomontacin, gigantetronenin, gigantetrocin A, and annonacin. Compounds 1 and 2 are unusual in having hydroxylation at C-8; 3 has the same functionalities as annonacin but with 37 carbons instead of 35 carbons. The structures were elucidated by spectral analysis of the parent compounds and/or simple chemical derivatives. These acetogenins showed cytotoxicities, comparable to adriamycin, against three human solid tumor cell lines.

One new phenylalkyl phenol, kneglomeratanol [1], and two new acetophenones, kneglomeratanones A [2] and B [3], together with ten known compounds, 3-(12'-phenyldodecyl)-phenol [4], 3-(10'-phenyldecyl)-phenol [5], 5-pentadecylresorcinol [6], 5-(10'-phenyldecyl)-resorcinol [7], 5-(12'-phenyldodecyl)-resorcinol [8], 2,4-dihydroxy-6-(10'-phenyldecyl)-acetophenone [9], 2-hydroxy-6-(12'-phenyldodecyl)-benzoic acid [10], formononetin, biochanin A, and 8-O-methylretusin, have been isolated from the stem bark of Knema glomerata. Brine shrimp lethality was used for the activity-directed chromatographic fractionations. All of these compounds showed moderate but significant toxicities to three human tumor cell lines and inhibited the growth of crown gall tumors on discs of potato tubers.

The relative stereochemistries of bullatalicin [1] and bullatalicinone [2] were partially reassigned based on COSY and relayed COSY spectra. The structures of annonins VIII [3], IV [4], and XVI [5] were revised and concluded as bullatalicin [1], bullatanocin [6], and squamostatin A [7], respectively.

To observe the biotransformation process of a Chinese compound, aesculin, by human gut bacteria, and to identify its metabolites in rat urine.Representative human gut bacteria were collected from 20 healthy volunteers, and then utilized in vitro to biotransform aesculin under anaerobic conditions. At 0, 2, 4, 8, 12, 16, 24, 48 and 72 h post-incubation, 10 mL of culture medium was collected. Metabolites of aesculin were extracted 3 x from rat urine with methanol and analyzed by HPLC. For in vivo metabolite analysis, aesculetin (100 mg/kg) was administered to rats via stomach gavage, rat urine was collected from 6 to 48 h post-administration, and metabolite analysis was performed by LC/ESI-MS and MS/MS in the positive and negative modes.Human gut bacteria could completely convert aesculin into aesculetin in vitro. The biotransformation process occurred from 8 to 24 h post-incubation, with its highest activity was seen from 8 to 12 h. The in vitro process was much slower than the in vivo process. In contrast to the in vitro model, six aesculetin metabolites were identified in rat urine, including 6-hydroxy-7-gluco-coumarin (M1), 6-hydroxy-7-sulf-coumarin (M2), 6, 7-di-gluco-coumarin (M3), 6-glc-7-gluco-coumarin (M4), 6-O-methyl-7-gluco-coumarin (M5) and 6-O-methyl-7-sulf-coumarin (M6). Of which, M2 and M6 were novel metabolites.Aesculin can be transferred into aesculetin by human gut bacteria and is further modified by the host in vivo. The diverse metabolites of aesculin may explain its pleiotropic pharmaceutical effects.

From the ether extract of the underground part of Notopterygium forbesii, two new coumarin glycosides, bergaptol-O-beta-D-glucopyranoside and 6'-O-trans-feruloylnodakenin, were isolated along with known compounds including seven furanocoumarins, two dihydrofuranocoumarins, a sterol glucoside and two phenolic compounds. Analysis of their contents by high-performance liquid chromatography (HPLC) revealed that the underground part of N. forbesii contained large amounts of p-hydroxphenethyl anisate (0.7%), bergaptol glucoside (0.2%), nodakenin (2%) and 6'-O-trans-feruloylnodakenin (0.7%) and a lesser amount of notopterol (0.08%), while that of N. incisum contained a large amount of notopterol (1.2%) and less amounts of the others. The characteristic difference in chemical composition between the two species enabled us to identify the respective botanical sources of a Chinese crude drug, Qiang-huo derived from N. incisum and N. forbesii by HPLC.