and their inhibitory effects on nitric oxide production

A phytochemical study of the aerial parts of Piper mutabile C. DC. revealed seven undescribed compounds [two (2-7')-neolignans and five polyoxygenated cyclohexene glycosides] and six known propenylcatechol derivatives. The chemical structures of the isolated compounds were elucidated by extensive HR-ESI-MS and NMR analyses, as well as comparison with the literature. The absolute configurations of the (2-7')-neolignans were confirmed by GIAO 13C NMR calculations with a sorted training set strategy and TD-DFT calculation ECD spectra. The (2-7')-neolignans and polyoxygenated cyclohexene glycosides are unusual in natural sources. Undescribed neolignans 1 and 2 inhibited NO production in RAW 264.7 cells, with respective IC50 values of 14.4 and 9.5 μM.

Ex vivo inhibition of PGE2 formation in human blood by four bicyclico [3.2.1] octane neolignans isolated from Aniba firmula bark, two with unusual structural pattern

The phytochemical investigation of the stem bark crude extract of Aniba firmula (Lauraceae) led to the isolation of undescribed bicyclic [3.2.1] octane neolignans, 1 and 2, characterized by unusual bicyclic patterns and two other known bicyclic neolignans 3 and 4. Anti-inflammatory bicyclic [3.2.1] octane neolignans metabolites were previously reported in the literature, and the A. firmula stands out in the Lauraceae family as a source of potentially bioactive compounds. Thus, herein the anti-inflammatory potential of four isolated compounds from A. firmula was accessed via an ex vivo anti-inflammatory model that included plasmatic quantification of the prostaglandin E2 (PGE2) inflammatory mediator. Compounds 2 and 3 exhibited significant anti-inflammatory activity by inhibiting the production of PGE2 in plasma samples, thus by interference with the cyclooxygenase (COX) inflammatory pathway. Therefore, these findings demonstrate that the bicyclic octane neolignan classes [3.2.1] can present anti-inflammatory potential.

Neolignan derivatives from Penthorum chinense with antitumor activity in human colorectal cancer cells by regulating Wnt/β-catenin signaling pathway

In vitro cytotoxicity-guided isolation based on a MTT assay was conducted for Penthorum chinense Pursh. (Penthoraceae). In the active components (EtOAc extract of P. chinense), eight undescribed neolignans, penthoneolignans A-H (1-8), and two known analogs (9 and 10) were obtained and identified. Their absolute configurations were determined by experimental and computational comparison of electronic circular dichroism spectra analysis. The MTT experiment results of the obtained neolignans on HT29 and LoVo cells indicated previously undescribed neolignans, penthoneolignans A (1) and F (6), showed better cytotoxicity than the positive drug 5-fluorouracil. Then, functional technologies such as the 5-ethyny1-2'-deoxyridine, wound healing, Transwell, and Western blot assays indicated that they could significantly inhibit the proliferation of HT29 and Lovo cells, promote apoptosis by up-regulating Bax, and down-regulating B-cell CLL/lymphoma 2 and poly ADP-ribose polymerase. Furthermore, a Western blot assay combining the Dsh homolog 2 agonist IWP-L6 and the β-catenin agonist MG132 suggested their mechanism of action was closely related to the inhibition of the Wnt/β-catenin signaling pathway. In conclusion, previously undescribed neolignans, penthoneolignans A (1) and F (6), may intervene in the development and progression of colorectal cancer by inhibiting the Wnt/β-catenin signaling pathway and have the potential to be drug candidates.

Neurotrophic neolignans of Pinus koraiensis twigs

Four undescribed neolignan analogs, together with eight known compounds, were isolated from the twigs of Pinus koraiensis (Korean pine). The chemical structure of the isolated compounds was determined through extensive spectroscopic analysis and chemical method. Their relative and absolute configurations were assigned through a well-established empirical rule and electronic circular dichroism (ECD) analysis, respectively. Four compounds (3 and 9-11) at 20 μM concentration showed significant neurotrophic effect by inducing nerve growth factor (NGF) secretion in C6 cells with the stimulation levels a range of 140.82 ± 4.62% to 160.04 ± 11.04%. Additionally, the result indicated that the glycosylation of neolignan led to an improvement in neurotrophic activity compared to their aglycone form. A compound (7) inhibited nitric oxide production with an IC50 value of 31.74 μM in LPS-activated BV2 cells.

Magnolol induces cytotoxic autophagy in glioma by inhibiting PI3K/AKT/mTOR signaling

Glioma is difficult-to-treat because of its infiltrative nature and the presence of the blood-brain barrier. Temozolomide is the only FDA-approved drug for its management. Therefore, finding a novel chemotherapeutic agent for glioma is of utmost importance. Magnolol, a neolignan, has been known for its apoptotic role in glioma. In this work, we have explored a novel anti-glioma mechanism of Magnolol associated with its role in autophagy modulation. We found increased expression levels of Beclin-1, Atg5-Atg12, and LC3-II and lower p62 expression in Magnolol-treated glioma cells. PI3K/AKT/mTOR pathway proteins were also downregulated in Magnolol-treated glioma cells. Next, we treated the glioma cells with Insulin, a stimulator of PI3K/AKT/mTOR signaling, to confirm that Magnolol induced autophagy by inhibiting this pathway. Insulin reversed the effect on Magnolol-mediated autophagy induction. We also established the same in in vivo glioma model where Magnolol showed an anti-glioma effect by inducing autophagy. To confirm the cytotoxic effect of Magnolol-induced autophagy, we used Chloroquine, a late-stage autophagy inhibitor. Chloroquine efficiently reversed the anti-glioma effects of Magnolol both in vitro and in vivo. Our study revealed the cytotoxic effect of Magnolol-induced autophagy in glioma, which was not previously reported. Additionally, Magnolol showed no toxicity in non-cancerous cell lines as well as rat organs. Thus, we concluded that Magnolol is an excellent candidate for developing new therapeutic strategies for glioma management.

Two new neolignans and an indole alkaloid from the stems of Nauclea officinalis and their biological activities

A pair of new diastereoisomers neolignans (1-2) and a new alkaloid (7) were isolated from the stems of Nauclea officinalis: naucleaoxyneolignoside A (1), naucleaoxyneolignoside B (2), (2S,3S)-javaniside (7), together with nine known compounds, 2S-3,3-di-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol (3), threo-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol (4), nauclefine (5), angustidine (6), naucleoxoside A (8), naucleoxoside B (9), angustoline (10), (3S,19S)-3,14-dihydroangustoline (11), and (3S,19R)-3,14-dihydroangustoline (12).The structures of 1, 2 and 7 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparison of their data with those reported in the literature. The absolution configurations of 1, 2, 7,11 and 12 were confirmed by the quantum chemical CD calculation method. Compounds 1-9 showed weak to moderate inhibitory activity on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC₅₀ values comparable to that of dexamethasone. In addition, compounds 1-9 were evaluated for the antibacterial and cytotoxic effects, and the results revealed that these compounds showed no anti-bacterial activity, and compounds 3-6 showed modest cytotoxic activity.

Identification of neolignans with PCSK9 downregulatory and LDLR upregulatory activities from Penthorum chinense and the potential in cholesterol uptake by transcriptional regulation of LDLR via SREBP2

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense has been used in East Asia for the treatment of cholecystitis, infectious hepatitis, jaundice and to treat liver problems. Recent evidences provided the potential for the clinical use of P. chinense in the treatment of metabolic disease.

AIM OF THE STUDY

Based on the traditional use and recent evidences, we investigated the effects of constituents from P. chinense with modulation on proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR) expression, and the effect of the most active substance on cholesterol uptake, and genes relevant to lipid metabolism.

MATERIALS AND METHODS

The isolation of compounds from the BuOH-soluble extract of 80% methanol extract of P. chinense was conducted using chromatographic methods and the structures were established by interpreting spectroscopic data. Quantitative real time-PCR, and Western blot analysis were performed to monitor the regulatory activity on PCSK9 and LDLR expression. PCSK9-LDLR binding interaction was also tested. The cholesterol uptake in hepatocyte was measured using 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI)-labeled LDL cholesterol. Additionally, gene network analysis of LDLR and responses of its target proteins were carried out to discover genes germane to the effect of active compound on HepG2 cells. Moreover, we performed protein-protein interaction analysis via String and constructed the compound target network using Cytoscape.

RESULTS

Two new neolignans and 37 known compounds were characterized from P. chinense. Of the isolated compounds, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3), penthorin A (4) and methyl gallate (25) were found to suppress PCSK9 mRNA expression with IC₅₀ values of 5.13, 15.56 and 11.66 μM, respectively. However, all the isolated compounds were found to be inactive in PCSK9-LDLR interaction assay. Additionally, a dibenzoxepine-type lignan analog, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) demonstrated to upregulate LDLR mRNA and protein expression via transcriptional factor sterol regulatory element-binding protein 2 (SREBP2). Furthermore, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) increase the LDL-cholesterol uptake in DiI-LDL assay.

CONCLUSION

(7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) seemed to increase potentially cholesterol uptake via the downregulation of PCSK9 and the activation of LDLR in hepatocytes. Moreover, SREBP2 was found to play an important role in regulation of PCSK9 and LDLR by (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one.

Structure elucidation and anti-inflammatory mechanism of difengpienol C, a new neolignan isolated from Illicium difengpi

Illicium difengpi is well-known as its stem barks that have been widely used in the Traditional Chinese Medicine (TCM) for therapy rheumatoid arthritis and traumatic injury. To comprehensive utilization of resources, the phytochemical investigation on the branches and leaves of this plant was carried out, which led to the isolation of an undescribed neolignan along with three known lignans. Their structures were elucidated on the basis of extensive spectroscopic data and the new compound was elucidated as a neolignan possessing a dihydropyran ring formed by a unique conjugation way and named difengpienol C. Difengpienol C showed the strongest anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, which powerfully inhibited nitric oxide (NO), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) production and suppressed the mRNA transcription of inducible nitric oxide synthase (iNOS), IL-6 and TNF-α. Besides, difengpienol C blocked the activation of TLR4/MyD88/NF-κB signaling pathway. Therefore, difengpienol C might be a potent agent for anti-inflammatory drug development, and the non-traditional medicinal parts of Illicium difengpi can be identified as the source of natural anti-inflammatory molecules.

Unique polyacetylenic ester-neolignan derivatives from Mitrephora tomentosa and their antimalarial activities

The phytochemical investigation of the methanol extracts of the leaves and twigs of Mitrephora tomentosa Hook. f. & Thomson resulted in the isolation and identification of undescribed polyacetylenic ester-neolignan derivatives, along with six known compounds. These six undescribed natural products were named as mitrephentosins A-F. The structures of these compounds were determined by spectroscopic techniques including UV, IR, NMR, and mass spectrometric analyses. The absolute configurations of mitrephentosins A-F were determined based on specific rotations values and ECD spectral data by comparisons made with the known parent neoligan compound mitredrusin. Mitrephentosins C, E, and F showed moderate antimalarial activities (IC₅₀ values of 13.3-24.6 μM) against the Plasmodium falciparum strains TM4/8.2 and K1CB1 and were not toxic to Vero cells, while the other isolated compounds were not active against these P. falciparum strains.

Sarcodactylis Swingle

The fruit of Citrus medica L. var. sarcodactylis Swingle is a functional food with rich nutrients and medicinal values because of its content of bioactive compounds. A bioactivity-guided chemical investigation from the fruits of C. medica L. var. sarcodactylis Swingle afforded three new benzodioxane neolignans (1-3), three new phenanthrofuran neolignan glycosides (4-6), two new biphenyl-ketone neolignans (7-8), two new 1',7'-bilignan neolignans (9-10), as well as fourteen known neolignan derivatives (11-24), which were isolated and characterized from the fruits of C. medica L. var. sarcodactylis Swingle for the first time. These neolignan derivatives were determined by extensive and comprehensive analyzing NMR, HR-ESI-MS, UV, IR spectral data and compared with the data described in the literature. Among them, compounds 1-3 and 12-13 exhibited moderate hepatoprotective activities to improve the survival rates of HepG2 cells from 46.26 ± 1.90% (APAP, 10 mM) to 67.23 ± 4.25%, 62.87 ± 4.43%, 60.06 ± 6.34%, 56.75 ± 2.30%, 58.35 ± 6.14%, respectively. Additionally, compounds 7-8 and 21-22 displayed moderate neuroprotective activities to raise the survival rates of PC12 cells from 55.30 ± 2.25% to 66.94 ± 3.37%, 70.98 ± 5.05%, 64.64 ± 1.93%, and 62.81 ± 4.11% at 10 μM, respectively. The plausible biogenetic pathway and preliminary structure-activity relationship of the selected compounds were scientifically summarized and discussed in this paper.

Semisynthesis and insecticidal bioactivities of benzoxazole and benzoxazolone derivatives of honokiol, a naturally occurring neolignan derived from Magnolia officinalis

Honokiol, a natural bioactive neolignan isolated from the bark and leaf of Magnolia officinalis and Magnolia obovata, exhibits many important biological properties. In continuation of our interest in discovery of the agrochemicals derived from the natural sources, thirty-seven new 8/8'-alkylthiol-benzoxazole and N-alkyl/sulfonyl-benzoxazolone derivatives of honokiol were prepared and their insecticidal activities were evaluated against the larvae of Mythimna separata Walker and Plutella xylostella Linnaeus. The results showed that eleven derivatives exhibited potent insecticidal activity against M. separata when compared with the positive control. Particularly, compound 5h displayed the most promising insecticidal activity against M. separata with the final mortality rate (FMR) of 58.6%. Meanwhile, compounds 7n (FMR = 65.3%), 7p (FMR = 61.5%), and 8c (FMR = 65.3%) demonstrated a greater insecticidal activity against P. xylostella than toosendanin, a well-known botanical insecticide. Additionally, the preliminary structure-activity relationships (SARs) were also discussed. This study indicates that these honokiol derivatives could be used as leads for the further derivation and development of the potential pesticide candidates for crop protection.

Diastereomeric identification of neolignan rhamnosides from Trochodendron aralioides leaves by LC-SPE-NMR and circular dichroism

Trochodendron aralioides is an old-existing relic plant with limited availability and only a few identified compounds. Accumulative analysis on the methanolic extract from its leaf part by LC-SPE-NMR resulted in the identification of seven new compounds, including three neolignan α-rhamnosides [(7R,8S)-dihydrodehydrodiconiferyl alcohol- 9-O-α-rhamnopyranoside (2) and 9'-O-α-rhamnopyranoside (3), and (7S,8R)-dehydrodiconiferyl alcohol-9'-O-α-rhamnopyranoside (4)], two isomeric oxyneolignan α-rhamnosides [(7R,8S)- (5) and (7R,8R)-icariside E₈ (6)), and (7R,8S)- (10) and (7R,8R)-icariside E₉ (11)], and two isomeric acylated fructofuranosyl mevalonolactones (13, 14), along with five known compounds (1, 7-9 and 12). The absolute configuration of the C-7 and C-8 positions for the new compounds 2-6 and 10-11 was assigned by comparison of the reported ECD spectra. Compounds 2, 3, 4, and 6 were further isolated by semi-preparative column chromatography for structure confirmation by 2D NMR spectroscopic analysis.

Tyrosinase inhibition by a rare neolignan: Inhibition kinetics and mechanistic insights through in vitro and in silico studies

Neolignans are a large group of polyphenols found in plants and exhibit a wide range of bioactivities including cytotoxicity, apoptosis inducer, antimalarial and antifungal effects, acetylcholinesterase, tyrosinase, and α-glucosidase inhibition. In this study we tested acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), tyrosinase, and α-glucosidase inhibitory effects of a rare neolignan, (-)-4-O-methyldehydrodiconiferyl alcohol 9'-O-β-glucopyranoside (1) in search for its new pharmaceutical effects. This compound exhibited good tyrosinase inhibition with an IC₅₀ value of 44.62 ± 3.99 μg/mL. Enzyme kinetics and molecular modelling studies were performed to provide insights into its tyrosinase inhibition mechanism.

Chemical constituents from Viburnum fordiae Hance and their anti-inflammatory and antioxidant activities

Three new neolignans, fordianoles A-C (1-3), characterized as (7S,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneolignan-7,7',9-triol, (7R,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneolignan-7,7',9-triol, and (7R,8R)-4-hydroxy-3,3',5'-trimethoxy-8,4'-oxyneolignan-7,9,9'-triol-7'-one, together with an unusual γ-lactone, 3-(3,4-dihydroxyphenyl)-4-pentanolide (4), and twenty-five known compounds (5-29) were isolated from the aerial parts of Viburnum fordiae Hance. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Among them, compounds 6, 7, 11-15, 17-28 were isolated from the Viburnum genus for the first time. The anti-inflammatory and antioxidant activities of all compounds were evaluated in vitro. Compounds 15, 19, 20 and 29 showed significant inhibitory activity on NO production in RAW264.7 cells stimulated by LPS with IC₅₀ values ranging from 8.60 to 13.92 μM. Meanwhile, compounds 1-4, 15, 19, 20, 22, 23, 25, 26 and 29 exhibited varying antioxidant activities through DPPH, ABTS free radical scavenging and FRAP assays.

Phytochemical study of Juglans regia L. leaves

A methanolic extract of Juglans regia L. leaves was fractioned by various chromatographic techniques yielding a total of 40 metabolites belonging to megastigmane, tetralone, phenylpropanoid, neolignane and juglone glycosides. Ten unknown megastigmane glucoside derivatives (juglanionosides A-K, 1-10) and six unknown tetralone glucoside derivatives (juglanosides J-O, 11-16) together with 24 known compounds - among them 16 described for the first time in Juglans - were isolated. As characteristic structural feature, the previously undescribed compounds showed acylation of the sugar units with sinapic, ferulic, coumaric, benzoic or salicylic acid. Their chemical structures were elucidated on the basis of 1D and 2D NMR techniques, HRESIMS as well as CD spectroscopy. Absolute stereochemistry was revealed by mild alkaline hydrolysis and comparison of CD and polarimetric data to literature values.

Neolignan and megastigmane glucosides from the aerial parts of Isodon japonicus with cell protective effects on BaP-induced cytotoxicity

Six neolignan glucosides, named isodonosides I-VI, and a megastigmane glucoside named isodonmegastigmane I, were isolated together with 15 known compounds from the methanolic extract of aerial parts of Isodon japonicus cultivated in Tokushima, Japan. The chemical structures of the compounds were elucidated based on their MS and NMR spectroscopic analysis. The absolute configurations of the neolignan and megastigmane glucosides were determined by derivatizations, by ECD (electronic circular dicroism) Cotton effect approximation, and by the modified Mosher's method. In addition, a significant cell protective effects of neolignan glucosides on benzo[a]pyrene-induced cytotoxicity was found.

Antioxidant and anti-inflammatory neolignans from the seeds of hawthorn

Seven new neolignans (1-2, 7-11) and five known compounds (3-6, 12) were isolated from the 70% EtOH extract of hawthorn seeds. Their structures were determined by spectroscopic analyses. The antioxidant and anti-inflammatory activities of all the isolates were investigated. Most of the isolates showed moderate radical scavenging activity in the DPPH assay and significant activities in the ABTS and FRAP assays. Furthermore, compounds 7-12 exhibited marked nitric oxide (NO) inhibition and compounds 1-4 had a potent necrosis factor-α (TNF-α) inhibitory effect. The results we obtained showed that hawthorn seeds can be regarded as a potential new and cheap source of antioxidants and inflammation inhibitors.

Expression and functional analyses of a putative phenylcoumaran benzylic ether reductase in Arabidopsis thaliana

A candidate gene for phenylcoumaran benzylic ether reductase in Arabidopsis thaliana encodes a peptide with predicted functional activity and plays a crucial role in secondary metabolism. Phenylcoumaran benzylic ether reductase (PCBER) is thought to be an enzyme crucial in the biosynthesis of 8-5'-linked neolignans. Genes of the enzyme have been isolated and characterized in several plant species. In this study, we cloned cDNA and the 5'-untranslated region of one PCBER candidate gene (At4g39230, designated AtPCBER1) from Arabidopsis thaliana. At the amino acid level, AtPCBER1 shows high sequence identity (64-71 %) with PCBERs identified from other plant species. Expression analyses of AtPCBER1 by reverse transcriptase-polymerase chain reaction and histochemical analysis of transgenic plants harboring the 5'-untranslated region of AtPCBER1 linked with gus coding sequence indicate that expression is induced by wounding and is expressed in most tissues, including flower, stem, leaf, and root. Catalytic analysis of recombinant AtPCBER1 with neolignan and lignans in the presence of NADPH suggests that the protein can reduce not only the 8-5'-linked neolignan, dehydrodiconiferyl alcohol, but also 8-8' linked lignans, pinoresinol, and lariciresinol, with lower activities. To investigate further, we performed metabolomic analyses of transgenic plants in which the target gene was up- or down-regulated. Our results indicate no significant effects of AtPCBER1 gene regulation on plant growth and development; however, levels of some secondary metabolites, including lignans, flavonoids, and glucosinolates, differ between wild-type and transgenic plants. Taken together, our findings indicate that AtPCBER1 encodes a polypeptide with PCBER activity and has a critical role in the biosynthesis of secondary metabolites in A. thaliana.

Cytotoxic activity of butane type of 1,7-seco-2,7'-cyclolignanes and apoptosis induction by Caspase 9 and 3

All stereoisomers of methoxybutane and fluorobutane type of 1,7-seco-2,7'-cyclolignane were synthesized and cytotoxic activities of these compounds were compared with those of all stereoisomers of butane and butanol type compounds. Both enantiomers of butane type secocyclolignane showed higher cytotoxic activity (IC50=16-20 μM) than methoxy type compounds, whereas none was observed for all the stereoisomers of butanol type secocyclolignane, however, (-)-Kadangustin J showed stereospecific cytotoxic activity (IC50=47-67 μM). Since (R)-9'-fluoro derivative 23 was most potent (IC50=19 μM) among the corresponding fluoro stereoisomers, (R)-9'-alkyl derivatives were synthesized, hydrophobic 9'-heptyl derivative 27 showing highest activity (IC50=3.7 μM against HL-60, IC50=3.1 μM against HeLa) in this experiment. Apoptosis induction caused by Caspase 3 and 9 for (R)-9'-heptyl derivative 27 was observed in the research on the mechanism. A degradation of DNA into small fragments was also shown by DNA ladder assay.

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7-24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.

Anti-inflammatory constituents from the fruits of Vitex rotundifolia

Three new diterpenes (7, 15 and 17) and two new neolignans (19 and 20) along with nineteen known compounds have been isolated from the fruits of Vitex rotundifolia. Their structures were elucidated by a combination of 1D and 2D NMR, HRESI-MS, and CD data. All isolates were tested for their inhibitory activities on LPS-induced nitric oxide production in RAW264.7 cells. Of these, compounds 3, 4, 7, 13, 15, 19, and 24 found to inhibit nitric oxide production with the IC50 values ranging from 11.3 to 24.5μM.