Synthesis and anti-HIV activity of oleanolic acid derivatives.

Thirteen oleanolic acid derivatives were prepared and evaluated for anti-HIV activity in H9 lymphocytes. Saturating the C(12)-C(13) double bond and converting the C(17)-carboxyl group to an aminomethyl group led to compounds 13-15 and 19-20, respectively, which showed improved anti-HIV activity. Compound 15 was the most potent derivative with EC(50)=0.0039 microg/mL and TI=3570.

Simple isoquinoline and benzylisoquinoline alkaloids as potential antimicrobial, antimalarial, cytotoxic, and anti-HIV agents.

Twenty-six simple isoquinolines and 21 benzylisoquinolines were tested for antimicrobial, antimalarial, cytotoxic, and anti-HIV activities. Some simple isoquinoline alkaloids were significantly active in each assay, and may be useful as lead compounds for developing potential chemotherapeutic agents. These compounds include 13 (antimicrobial), 25, 26, and 42 (antimalarial), 13 and 25 (cytotoxic), and 28 and 29 (anti-HIV). A quaternary nitrogen atom of isoquinolium or dihydroisoquinolinium type may contribute to enhanced potency in the first three types of activities. In contrast, anti-HIV activity was found with tetrahydroisoquinoline and 6,7-dihydroxyisoquinolium salts.

Anti-AIDS agents. 42. Synthesis and anti-HIV activity of disubstituted (3'R,4'R)-3',4'-di-O-(S)-camphanoyl-(+)-cis-khellactone analogues.

A series of disubstituted 3',4'-di-O-(S)-camphanoyl-(+)-cis-khellactone (DCK) analogues (1-10) were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. 5-Methoxy-4-methyl DCK (8) was the most promising compound with an EC(50) value of 7.21 x 10(-6) microM and a therapeutic index of >2.08 x 10,(7) which were much better than those of lead compound DCK in the same assay. Another six disubstituted DCK analogues (1-5 and 7) were more potent than AZT but less active than DCK. Conformational analysis suggested that resonance of the coumarin system is an essential structural feature for potent anti-HIV activity. Steric compression of C(4) and C(5) substituents of the coumarin moiety can reduce the overall planarity and thus resonance of the coumarin nucleus, resulting in a decrease or lack of anti-HIV activity.

3,28-Di-O-(dimethylsuccinyl)-betulin isomers as anti-HIV agents.

Four isomers of 3,28-di-O-(dimethylsuccinyl)-betulin were prepared and evaluated for anti-HIV activity against HIV-1 replication in H9 lymphocyte cells. 3-O-(3',3'-Dimethylsuccinyl)-28-O-(2", 2"-dimethvlsuccinyl)-betulin (11) was the most potent anti-HIV compound with an EC5, value of 0.00087 microM and a TI value of 42,400.

Apoptosis: a method for evaluating the cryopreservation of whole blood and peripheral blood mononuclear cells.

We sought to compare the effect of cryopreservation and storage at -30 degrees C, -70 degrees C and -150 degrees C of human whole blood versus matched peripheral blood mononuclear cell (PBMC) samples using apoptosis as an indicator of cell fitness. Following 10 weeks of storage the samples were thawed and assessed for viability (trypan blue exclusion), levels of apoptosis (using the nuclear stain bis-benzimide) and cell function (ability to be transformed by Epstein-Barr virus, EBV). When comparing storage temperatures, the levels of apoptosis in whole blood and PBMC samples stored at -30 degrees C were significantly higher than the values for samples stored at -70 degrees C or -150 degrees C (P<0.004). Whole blood samples stored at -150 degrees C had significantly less apoptosis than those stored at -70 degrees C (P<0.03). A comparison of the cell preparations showed that at all three storage temperatures there was significant sample deterioration (viability, apoptosis, and function) in whole blood relative to PBMC samples. This study indicates that careful consideration should be given to storage conditions and that apoptosis can be used as a sensitive measure of cell fitness following cryopreservation.

Synthesis and anti-HIV activity of 3-alkylamido-3-deoxy-betulinic acid derivatives.

3-Alkylamido-3-deoxy-betulinic acids were synthesized and evaluated for anti-HIV activity as part of the structure-activity relationship study of the potent anti-HIV agent 3-O-(3',3'-dimethyl)-succinyl-betulinic acid (DSB) (2). 3Alpha-diglycorylamide-3-deoxy-betulinic acid demonstrated relatively potent anti-HIV activity (EC50 0.24 microm, TI 728). However, replacing the ester group at C-3 in 2 and its analogues with an amido group yielded inactive or much less potent compounds against HIV replication, indicating that the ester group at C-3 in 2-4 is essential for potent anti-HIV activity.

Anti-AIDS agents part 41: synthesis and anti-HIV activity of 3',4'-di-o-(-)-camphanoyl-(+)-cis-khellactone (DCK) lactam analogues.

DCK lactam analogues were synthesized and evaluated for anti-HIV activity against HIV-1 replication in H9 lymphocyte cells. 4-Methyl-DCK lactam (11a) exhibited potent anti-HIV activity with EC50 and therapeutic index values of 0.00024 microM and 119,333, respectively.

Sesquiterpene alkaloids from Tripterygium hypoglaucum and Tripterygium wilfordii: a new class of potent anti-HIV agents.

Five new sesquiterpene pyridine alkaloids [triptonines A (1) and B (2), and wilfordinines A (3), B (4), and C (5)] and two known compounds (peritassine A and hypoglaunine C) were isolated from Tripterygium hypoglaucum and a clinically used extract of Tripterygium wilfordii. The structures of 1-5 were elucidated by spectroscopic methods. The anti-HIV activity of 1, 2, and several related compounds was evaluated. Triptonine B (2) demonstrated potent anti-HIV activity with an EC(50) value of <0.10 microg/mL and an in vitro therapeutic index value of >1000.

Anti-AIDS agents 38. Anti-HIV activity of 3-O-acyl ursolic acid derivatives.

Based on our previous finding that 3-O-acyl-betulinic and -oleanolic acids, especially the 3-O-(3',3'-dimethyl)-succinyl derivatives (2 and 4), demonstrated potent anti-HIV activity [EC(50) < 0.00035 and 0.00086 microM; therapeutic index (TI) > 20 000 and 22 326, respectively], several 3-O-acyl-ursolic acids were prepared and evaluated for anti-HIV activity. Ursolic acid (6) was equipotent (EC(50) 4.4 microM) with oleanolic acid (EC(50) 3.7 microM), although it was slightly toxic (IC(50) 14.3 microM, TI 3.3). 3-O-Diglycoryl-ursolic acid (10) demonstrated relatively potent anti-HIV activity with an EC(50) of 0. 31 microM and a TI of 155.5. In contrast, 3-O-(3', 3'-dimethylsuccinyl)-ursolic acid (8), which is analogous to the extremely potent anti-HIV betulinic acid and oleanolic acid derivatives 2 and 4, displayed only weak anti-HIV activity (EC(50) 2.1 microM, TI 23.6).

Anti-AIDS agents. Part 36: 17-carboxylated steroids as potential anti-HIV agents.

In our search for novel anti-HIV agents, seven 17-carboxylated steroid derivatives were synthesized and evaluated as potential anti-HIV agents. Compound 13 exhibited potent anti-HIV activity in acutely infected H9 lymphocytes with EC50 and therapeutic index values of 0.8 microM and 300, respectively.

Anti-AIDS agents. 37. Synthesis and structure-activity relationships of (3'R,4'R)-(+)-cis-khellactone derivatives as novel potent anti-HIV agents.

To explore the structural requirements of (+)-cis-khellactone derivatives as novel anti-HIV agents, 24 monosubstituted 3', 4'-di-O-(S)-camphanoyl-(+)-cis-khellactone (DCK) derivatives were synthesized asymmetrically. These compounds included 4 isomeric monomethoxy analogues (3-6), 4 isomeric monomethyl analogues (7-10), 4 4-alkyl/aryl-substituted analogues (11-14), and 12 4-methyl-(+)-cis-khellactone derivatives (15-26) with varying 3', 4'-substituents. These (+)-cis-khellactone derivatives were screened against HIV-1 replication in acutely infected H9 lymphocytes. The results demonstrated that the (3'R,4'R)-(+)-cis-khellactone skeleton, two (S)-(-)-camphanoyl groups at the 3'- and 4'-positions, and a methyl group on the coumarin ring, except at the 6-position, were optimal structural moieties for anti-HIV activity. 3-Methyl- (7), 4-methyl- (8), and 5-methyl- (9) 3',4'-di-O-(S)-camphanoyl-(3'R, 4'R)-(+)-cis-khellactone showed EC(50) and therapeutic index values of <5.25 x 10(-5) microM and >2.15 x 10(6), respectively, in H9 lymphocytes, which are much better than those of DCK and AZT in the same assay. Furthermore, 8 and 9 also showed potent inhibitory activity against HIV-1 replication in the CEM-SS cell line, and most monosubstituted DCK analogues were less toxic than DCK in both assays.

Substituted 7H-pyrido[4,3-c]carbazoles with potent anti-HIV activity.

Several substituted 7H-pyrido[4,3-c]carbazoles were synthesized from the natural product mukonal and tested for inhibition of HIV replication in H9 lymphocytes. 5-Methoxy-7-methyl-7H-pyrido[4,3-c]carbazole (7) had an EC50 value of 0.0054 microgram/mL and the highest therapeutic index (TI = 503) in the series.

Novel anti-HIV lancilactone C and related triterpenes from Kadsura lancilimba.

Three new triterpene lactones, lancilactones A (1), B (2), and C (3), together with the known kadsulactone A (4), were isolated from the stems and roots of Kadsura lancilimba. Their structures and stereochemistries were determined primarily from mass and NMR spectral data. Compound 3 inhibited HIV replication with an EC50 value of 1.4 microg/mL and a therapeutic index of greater than 71.4.

Anti-AIDS agents. 34. Synthesis and structure-activity relationships of betulin derivatives as anti-HIV agents.

Succinyl and 3'-substituted glutaryl betulin derivatives showed stronger anti-HIV activity and higher therapeutic index (TI) values than their dihydrobetulin counterparts, with ratios of 1.2:1 to 15:1 (cf. 7 and 15, 9 and 17, 10 and 18, 11 and 19, and 12 and 20). For various 3'-substituted glutaryl compounds, the order of anti-HIV effects, from strong to weak inhibition, was 3',3'-dimethyl, 3'-methyl, 3'-ethyl-3'-methyl, followed by 3',3'-tetramethylene glutaryl derivatives (10 > 9 > 11 > 12, 18 > 17 > 19 > 20). The most potent compound, 10, has two 3',3'-dimethylglutaryl groups and displays significant anti-HIV potency with an EC50 value of 0.000 66 microM and a TI of 21 515. Results for compounds (22 and 23) without a C-3 acyl group confirmed the importance of the C-3 acyl group to the anti-HIV effect. With 3',3'-tetramethylene glutaryl derivatives, triacyl 29 showed stronger inhibition than diacyl 12; in contrast, 3',3'-dimethylglutaryl compounds displayed opposite results. 3-Keto compounds (35 and 36) and 2,3-dihydro compounds (39 and 40) had EC50 values in the range of 4.3-10.0 microM, suggesting that A ring modification led to decreased potency. The reduced activity of amide (33 and 34), ester (41), and oxime (42) analogues suggested that the orientation and linkage of the C-3 acyl side chain play crucial roles in the potent anti-HIV activity. Finally, replacing the C-28 acyl group with a bulky non-carboxylic group produced a less potent compound (44). In the study of mechanism of action, our results indicated that fusion is not the primary target for the anti-HIV activity of 10. It appears to inhibit HIV replication at a late stage of the viral life cycle, i.e., after viral protein synthesis.

Anti-AIDS agents. 30. Anti-HIV activity of oleanolic acid, pomolic acid, and structurally related triterpenoids.

Oleanolic acid (1) was identified as an anti-HIV principle from several plants, including Rosa woodsii (leaves), Prosopis glandulosa (leaves and twigs), Phoradendron juniperinum (whole plant), Syzygium claviflorum (leaves), Hyptis capitata (whole plant), and Ternstromia gymnanthera (aerial part). It inhibited HIV-1 replication in acutely infected H9 cells with an EC50 value of 1.7 microg/mL, and inhibited H9 cell growth with an IC50 value of 21.8 microg/mL [therapeutic index (T. I.) 12.8]. Pomolic acid, isolated from R. woodsii and H. capitata, was also identified as an anti-HIV agent (EC50 1.4 microg/mL, T. I. 16.6). Although ursolic acid did show anti-HIV activity (EC50 2.0 microg/mL), it was slightly toxic (IC50 6.5 microg/mL, T. I. 3.3). A new triterpene (11) was also isolated from the CHCl3-soluble fraction of R. woodsii, though it showed no anti-HIV activity. The structure of 11 was determined to be 1beta-hydroxy-2-oxopomolic acid by spectral examination. Based on these results, we examined the anti-HIV activity of oleanolic acid- or pomolic acid-related triterpenes isolated from several plants. In addition, we previously demonstrated that derivatives of betulinic acid, isolated from the leaves of S. claviflorum as an anti-HIV principle, exhibited extremely potent anti-HIV activity. Accordingly, we prepared derivatives of oleanolic acid and evaluated their anti-HIV activity. Among the oleanolic acid derivatives, 18 demonstrated most potent anti-HIV activity, with an EC50 value of 0. 0005 microg/mL and a T. I. value of 22 400.

Anti-AIDS agents. 32. Synthesis and anti-HIV activity of betulin derivatives.

Eleven betulin derivatives were prepared and evaluated for anti-HIV activity in H9 lymphocytes. Compound 4 was found to be the most active with EC50 and TI values of 0.00066 microM and 21,515, respectively.

Major liver resection for non-Hodgkin's lymphoma in an HIV-positive patient: report of a case.

A very unusual clinical presentation of non-Hodgkin's lymphoma (NHL) of the liver is reported herein. The patient was a 35-year-old male who had been HIV-positive since 1987. Following an episode of acute pain in the right upper abdominal quadrant, ultrasonography (US) and computed tomography (CT) were performed, revealing a nodular lesion, 2.5 cm in diameter, localized in the eighth segment of the liver. Despite the fact that the lesion became significantly enlarged over a 6-month period, three repeated percutaneous biopsies proved negative. Finally, his increasing pain and the lack of a definitive diagnosis prompted us to perform a right hepatectomy. The patient had an uneventful postoperative course and is well 1 year after his operation. Establishing a diagnosis of extranodal lymphoma can be difficult, especially in HIV-positive or AIDS patients. Thus, performing a laparotomy is justified to confirm a diagnosis and decide upon the most appropriate treatment. However, in about 10% of these patients, only surgical resection allows for the diagnosis. In accordance with other reports, our experience confirms that, in contrast with AIDS patients, HIV-positive patients have a similar prognosis as non-HIV patients, and are suitable candidates for even major surgical procedures.

Anti-AIDS agents. 31. Synthesis and anti-HIV activity of 4-substituted 3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (DCK) thiolactone analogs.

Four DCK-thiolactone analogs (3-6) were synthesized asymmetrically and evaluated for anti-HIV activity against HIV-1 replication in H9 lymphocyte cells. Based on the functionality on the thiolactonecoumarin nucleus, activity was in the order: methyl > H > propyl > benzyl. 4-Methyl-3',4'-di-O-(-)-camphanoyl-(+)-cis-khelthiolactone (4) exhibited extremely potent anti-HIV activity with EC50 and therapeutic index values of 0.00718 microM and > 21,300, respectively.

Anti-AIDS agents. 33. Synthesis and anti-HIV activity of mono-methyl substituted 3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (DCK) analogues.

Four isomeric methyl substituted DCK analogues (2-5) were asymmetrically synthesized from different starting materials. 3-Methyl, 4-methyl, and 5-methyl-3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (2-4) all were extremely potent against HIV-1 replication in H9 lymphocyte cells with EC50 and therapeutic index values of < 4.23 x 10(-7) microM and > 3.72 x 10(8), respectively, which are much better than those of DCK and AZT in this assay.

Anti-AIDS agents--XXVI. Structure-activity correlations of gomisin-G-related anti-HIV lignans from Kadsura interior and of related synthetic analogues.

Bioactivity-directed fractionation of an ethanolic extract of the stems of Kadsura interior led to the isolation and identification of 12 known lignans (1-12). Seven of these compounds (1, 6, 8-12) were active as anti-HIV agents. Gomisin-G (11) exhibited the most potent anti-HIV activity with EC50 and therapeutic index (TI) values of 0.006 microgram/mL and 300, respectively. Schisantherin-D (6), kadsuranin (8), and schisandrin-C (10) showed good activity with EC50 values of 0.5, 0.8, and 1.2 micrograms/mL, and TI values of 110, 56, and 33.3, respectively. Ten related synthetic biphenyl compounds, five variously substituted bismethylenedioxy, dimethoxy, and dimethoxycarbonyl isomers (18-22) and five brominated derivatives (23-27) also were evaluated for inhibitory activity against HIV-1 replication in acutely infected H9 cells. The total syntheses of two new isomers (21 and 22) are reported for the first time. The anti-HIV data indicated that the relative position and types of substituents on the phenolic hydroxy groups of either the natural lignans or the synthetic biphenyl compounds rather than the numbers of bromine(s) on the aromatic rings are of primary importance. In the cyclooctane ring of the natural lignans, the position and substitution of hydroxy groups are also important to enhanced anti-HIV activity.