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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.

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).

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.

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.

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.

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.

A novel cytotoxic Annonaceous acetogenin, the first member of this class of compounds having a tri-tetrahydrofuran (THF) moiety, has been isolated from Goniothalamus giganteus. The structure was elucidated by spectral data, and the absolute configuration was determined by advanced Mosher's methodology.

Annonaceous acetogenins are waxy substances consisting of C32 or C34 long chain fatty acids which have been combined with a propan-2-ol unit at C-2 to form a gama-lactone. They are only found in several genera of the plant family, Annonaceae. Their diverse bioactivities as antitumour, immunosuppressive, pesticidal, antiprotozoal, antifeedant, anthelmintic and antimicrobial agents have attracted more and more interest worldwide. Recently, we reported that the Annonaceous acetogenins can selectively inhibit the growth of cancerous cells and also inhibit the growth of adriamycin resistant tumour cells. As more acetogenins have been isolated and additional cytotoxicity assays have been conducted, we have noticed that, al(hough most acetogenins have high potencies among several solid human tumour cells lines, some of the derivatives within the different structural types and some positional isomers show remarkable selectivities among certain cell lines, e.g. against prostate cancer (PC-3).

Using the brine shrimp lethality test (BST) to direct fractionation, two additional Annonaceous acetogenins, bullacin (1) and parviflorin (2), were isolated from the ethanol extract of the bark of Annona bullata Rich. Their absolute stereochemistries were revealed by the use of Mosher's methodology. Compound (1) is a new adjacent bis-tetrahydrofuran (THF) acetogenin possessing a relatively rare C 35 skeleton and an unprecedented C-6 hydroxyl group. The absolute configuration of 1 was assigned as 6S, 13R, 14R, 17R, 18R, 21R, 22R, and 34S. Compound (2) is a known acetogenin but is new to this plant. The absolute configuration of 2 was concluded to be 4R, 13R, 14R, 17R, 18R, 21R, 22R, and 34S. This is the first paper in which the absolute stereochemistry of a new acetogenin is published with the hew structure. 1 showed 10 to 1000 times the cytotoxic potency of adriamycin when tested in huam tumor cell lines