An anti-complementary polysaccharide from the roots of Bupleurum chinense

Extraction, characterization, antioxidation and anti-inflammatory activity of polysaccharides from Bupleurum chinense based on different molecular weights

Bupleurum chinense polysaccharide has a wide range of biological activities. In this study, Bupleurum chinense polysaccharides (BPs), BPs-1 (30 kDa) and BPs-2 (2000 kDa) with different molecular weights were isolated and prepared by ultrafiltration interception method. The structures of BPs, BPs-1 and BPs-2 were characterised by monosaccharide composition, GC-MS, Fourier transform infra-red spectroscopy and nuclear magnetic resonance. The results showed that the monosaccharide composition of BPs with different molecular weights was the same, but the proportion was different. BPs, BPs-1 and BPs-2 were mainly connected by Glup-(1→,→2,4)-Araf-(1→,→6)-Glup-(1→). The anti-inflammatory activity screening experiment in vitro showed that BPs-1 had stronger anti-inflammatory effect. Antioxidant experiments showed that BPs-2 had high free radical scavenging activity. This study laid a foundation for elucidating the fine structure and structure-activity relationship of Bupleurum chinense polysaccharides and will promote the product development of Bupleurum chinense polysaccharides.

Functional properties, structural characteristics, and anti-complementary activities of two degraded polysaccharides from strawberry fruits

Two low-molecular-weight polysaccharides (DPSP50 and DPSP70) were obtained using hydrogen peroxide-vitamin C (H2O2-Vc) treatment at 50 °C and 70 °C, respectively. Both DPSP50 and DPSP70 comprised the same six monosaccharides in different ratios, and their molecular weights (Mws) were 640 kDa and 346 kDa, respectively. Functional properties analyses demonstrated that DPSP50 and DPSP70 each had an excellent water holding capacity, oil absorption capacity, and emulsion properties, as well as shear-thinning characteristics and viscoelastic properties. Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic assays confirmed the existence of α-, β-pyranose rings and the same six sugar residues in DPSP50 and DPSP70. The results of Congo red test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) demonstrated that DPSP50 and DPSP70 did not contain triple-helix conformations, but were amorphous aggregates with flake-like shape and rough surface. Additionally, both DPSP50 and DPSP70 showed strong anti-complementary activities through the classical pathway and the alternative pathway. The results support the potential utility of these degraded polysaccharides from strawberry fruits in functional foods and medicines.

Comparative Study on Anti-Inflammatory Effect of Polysaccharides from Vinegar-Baked Radix Bupleuri Using Different Methods

The impact of the extraction method on the physiochemical characteristics and anti-inflammatory effect of polysaccharides from vinegar-baked Radix Bupleuri (VBCPs) was studied. Five extraction methods were employed to obtain the VBCPs: hot water extraction (HW), ultrasound-assisted extraction (UA), enzyme-assisted extraction (EA), citric acid-assisted extraction (CA), and ammonia-assisted extraction (KA). The results showed that the extraction method affects the yield, characteristics, and anti-inflammatory effect of the polysaccharides significantly. KA produced the highest yield, Ara content, and the strongest effect of enhancing IL-10 secretion. VBCP-EA exhibited the largest molecular weight (Mw), the highest Man content, and the poorest effect on inhibiting NO, VBCP-UA possessed more Gal than other VBCPs, the lowest Mw, and a comparable effect on inhibiting NO and TNF-α with VBCP-KA and VBCP-CA. All VBCP self-assembled into nanoparticles in solutions, and VBCP-KA presented the lowest particle size. The structure-activity analysis showed that Mw and Man content are negatively correlated and Ara content is positively correlated with the NO inhibition and IL-10 secretion effects; Rha and Gal A content are positively correlated and Glu is negatively correlated with the TNF-α inhibiting effect. The above results indicated that KA is an efficient method for obtaining anti-inflammatory VBCP, which provides new insight into the extraction of VBCP.

Structure and potential anti-fatigue mechanism of polysaccharides from Bupleurum chinense DC

Two polysaccharides, BCP-1 and BCP-2, were obtained from Bupleurum chinense DC. by water extraction and ultrafiltration. BCP-1 (1.04 × 10⁵ Da) and BCP-2 (2.14 × 10⁴ Da) were composed of Mannose, Rhamnose, Glucose, Galactose, Arabinose, and Galacturonic acid in different proportions. They both contained oligogalacturonides in their main chain. Besides, the backbone of BCP-1 was composed of 4-β-Galp and 4,6-β-Glcp, and branched at C4 of 4,6-β-Glcp. While BCP-2 contained a backbone of 3,5-α-Araf residues with branches at C3. BCP-2 effectively extended the forced swimming time, improved the glycogen reserves and antioxidant system, decreased the levels of blood urea nitrogen, lactic acid, lactate dehydrogenase and creatinine kinase expression. It alleviated physical fatigue through regulating 5'-AMP-activated protein kinase (AMPK) and Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) signalling pathway in skeletal muscles. This study demonstrated that BCP-2 exhibited more effective anti-fatigue activity than BCP-1 potentially associated with its primary and higher structures.

Extraction, purification, structure characteristics, biological activities and pharmaceutical application of Bupleuri Radix Polysaccharide: A review

Bupleuri Radix (BR), as a well-known plant medicine of relieving exterior syndrome, has a long history of usage in China. Bupleuri Radix Polysaccharide (BRP), as the main component and an important bioactive substance of BR, has a variety of pharmacological activities, including immunoregulation, antioxidant, antitumor, anti-diabetic and anti-aging, etc. In this review, the advancements on extraction, purification, structure characteristics, biological activities and pharmaceutical application of BRP from different sources (Bupleurum chinense DC., Bupleurum scorzonerifolium Willd., Bupleurum falcatum L. and Bupleurum smithii Woiff. var. Parvifolium Shan et Y. Li.) are summarized. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research on BRP, and new valuable insights for the future researches of BRP are proposed.

The Structural Characteristics of an Acidic Water-Soluble Polysaccharide from Bupleurum chinense DC and Its In Vivo Anti-Tumor Activity on H22 Tumor-Bearing Mice

This study explored the preliminary structural characteristics and in vivo anti-tumor activity of an acidic water-soluble polysaccharide (BCP) separated purified from Bupleurum chinense DC root. The preliminary structural characterization of BCP was established using UV, HPGPC, FT-IR, IC, NMR, SEM, and Congo red. The results showed BCP as an acidic polysaccharide with an average molecular weight of 2.01 × 10³ kDa. Furthermore, we showed that BCP consists of rhamnose, arabinose, galactose, glucose, and galacturonic acid (with a molar ratio of 0.063:0.788:0.841:1:0.196) in both α- and β-type configurations. Using the H22 tumor-bearing mouse model, we assessed the anti-tumor activity of BCP in vivo. The results revealed the inhibitory effects of BCP on H22 tumor growth and the protective actions against tissue damage of thymus and spleen in mice. In addition, the JC-1 FITC-AnnexinV/PI staining and cell cycle analysis have collectively shown that BCP is sufficient to induce apoptosis and of H22 hepatocarcinoma cells in a dose-dependent manner. The inhibitory effect of BCP on tumor growth was likely attributable to the S phase arrest. Overall, our study presented significant anti-liver cancer profiles of BCP and its promising therapeutic potential as a safe and effective anti-tumor natural agent.

Plants arabinogalactans: From structures to physico-chemical and biological properties

Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or chemically bound to pectin rhamnogalactan. Type I with predominantly β-d-(1 → 4)-galactan and type II with β-d-(1 → 3) and/or (1 → 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.

Molecular Identification Based on Chloroplast Sequences and Anti-complementary Activity Comparison of Juniperus Samples from the Qinghai-Tibet Plateau

Juniperus (Cupressaceae, Pinales) plants are widely distributed in the Qinghai-Tibet Plateau of China. The leaves and twigs of at least 8 Juniperus species (J. pingii, J. pingii var. wilsonii, J. squamata, J. recurva var. coxii, J. saltuaria, J. indica, J. tibetica and J. convallium var. microsperma) have been used as the Tibetan medicine Xuba. At present, it is difficult to distinguish among the original species of Xuba based only on their similar morphological characteristics. However, in our previous studies, 4 Xuba samples from different Juniperus species exhibited significant differences in both anticomplementary activity in vitro and anti-inflammatory effects on acute lung injury in vivo. To identify the effective original species of Xuba reliably, in this study, we developed a sequencing-based DNA molecular technology to distinguish 14 populations of 8 Juniperus species collected from Tibet region, using trnS-G, trnD - T, and petN-psbM genomic regions to build phylogenetic trees. In addition, their anticomplementary activities were evaluated. The results showed that combined sequence of these 3 genomic regions could identify 8 Juniperus species clearly and clustered individuals of one species but from different locations, whichever phylogenetic tree was constructed. Moreover, the anticomplementary activities of the 8 species were clustered into 2 groups. Among them, J. saltuaria and J. recurva var. coxii, which formed an independent branch apart from the other 6 species in phylogenetic trees, were the most potent (CH₅₀: 0.029 - 0.032 mg/mL). Consequently, DNA identification of Juniperus using the combined sequence could provide beneficial guidance for further efficacy evaluation and quality control of Xuba.

Structural Characterization of Pectic Polysaccharides From Bupleurum chinense DC

Bupleurum chinense DC, a traditional medicinal plant in China that has many pharmacological effects, contains polysaccharide as one of its active components. In this study, we isolated and structurally characterized the polysaccharide from B. chinense. Water-soluble polysaccharides (termed WBCP) were extracted from the plant and fractionated by anion-exchange and size exclusion chromatographies. From this procedure, we obtained a homogeneous acidic polysaccharide (WBCP-A2) and determined its monosaccharide composition. Analysis by FT infrared and 13C NMR spectroscopies, along with enzymatic hydrolysis, indicated that WBCP-A2 is a pectic polysaccharide, composed of rhamnogalacturonan I, rhamnogalacturonan II, highly methyl-esterified homogalacturonan (HG), and either non- or low methyl-esterified HG domains. These different fractions may be covalently linked through HG segments to form the complex pectin molecules.

Structural characterization and anticomplement activity of an acidic polysaccharide from Hedyotis diffusa

An acidic homogeneous polysaccharide (HD-PS-1) was purified from Hedyotis diffusa (Willd.) Roxb. HD-PS-1 possessed a backbone chain of →[4)-β-Glcp-3-OAc-(1]₆→[6)-β-Manp-(1]₂→6)-α-Galp-(1→[4)-α-Galp-(1]₂→, with three branches of β-Manp-(1→3)-β-GlcpA, α-Rhap-(1→3)-α-Rhap and α-Galp attached to the backbone chain at O-4 position of 1,4,6-linked β-Manp, O-3 position of 1,3,6-linked α-Galp and O-3 position of 1,3,4-linked α-Galp, respectively. HD-PS-1 exhibited significant anticomplement activity (CH₅₀: 0.084 ± 0.009 mg/mL, AP₅₀: 0.176 ± 0.013 mg/mL). It was found that the presence of uronic acids is important to anticomplement activity of HD-PS-1, given that the reduced HD-PS-1 showed weaker activity (CH₅₀: 0.456 ± 0.008 mg/mL, AP₅₀: 0.572 ± 0.010 mg/mL). Preliminary mechanism study indicated that HD-PS-1 interacted with C3 and C4 in the complement activation cascade. In addition, a neutral homogeneous polysaccharide (HD-PS-2) was also purified and characterized. HD-PS-2 displayed antioxidant activity by scavenging DPPH· radicals without anticomplement activity.

Structural characterization and anticomplement activity of an acidic polysaccharide containing 3-O-methyl galactose from Juniperus tibetica

A water-soluble acidic polysaccharide containing 3-O-methyl galactose, named YB-PS4, was isolated from the twigs and leaves of Juniperus tibetica Kom. Its structure was characterized by monosaccharide composition analysis, methylation, and NMR spectroscopy. It was concluded that YB-PS4 had a backbone composed of→2,4)-α-Rhap-(1→, →3,5)-α-Araf-(1→, →2,4)-α-Galp-(1 → and →4)-α-GalpA-(1→, with branches of →2)-α-Rhap-(1→,→3)-α-Araf-(1 → and →2)-3-O-Me-α-Galp-(1→. The possible repetitive units were speculated and further analyzed by oligosaccharide analysis. YB-PS4 showed inhibitory effects on complement activation through the classical pathway (CH₅₀ = 94.23 ± 8.90 μg/mL) and alternative pathway (AP₅₀ = 194.76 ± 9.20 μg/mL). Preliminary mechanism study indicated that it interacted with C1q, C2, C3, C4 and C5. These studies pointed a way to understand the active constituents of J. tibetica and provided scientific bases for YB-PS4 as a complement inhibitor.

Beneficial effects on H1N1-induced acute lung injury and structure characterization of anti-complementary acidic polysaccharides from Juniperus pingii var. wilsonii

Juniperus pingii var. wilsonii has been traditionally used in Tibetan medicine for the treatment of inflammatory diseases. In the present study, J. pingii var. wilsonii polysaccharides (JPWP), with high content of d‑galacturonic acid, showed potent anti-complementary activity in vitro and significantly attenuated acute lung injury (ALI) induced by H1N1 influenza virus in vivo through reducing the inflammatory responses, alleviating oxidative stress and inhibiting the activation of complement. Thus, anti-complementary activity-guided fractionation of JPWP led to the isolation of an acidic homogeneous polysaccharide, JPWP-PS, whose structure was further elucidated by acid hydrolysis, PMP derivation, methylation and NMR analysis. JPWP-PS had potent anti-complementary activity with the CH₅₀ value of 0.073 ± 0.009 mg/mL, and was characterized by the residues of T-Araf-(1→, →3)-Araf-(1→, →3,5)-Araf-(1→, →3)-Galp-(1→ and →4)-GalpA-(1→.

Protective effects of a traditional herbal extract from Stellaria dichotoma var. lanceolata against Mycobacterium abscessus infections

Stellaria dichotoma var. lanceolata (SdLv), a member of the Caryophyllaceae, is a traditional herbal medicine that has been used to treat fever, night sweats, and malaria in East Asia. Inflammation plays an essential role in both host defense and pathogenesis during infection by diverse intracellular pathogens. Herein, we showed that an herbal extract from SdLv effectively attenuated inflammatory responses from infection of Mycobacterium abscessus (Mab), but not Toxoplasma gondii (T. gondii). In primary murine macrophages, Mab infection resulted in the rapid activation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK), as well as in the generation of proinflammatory cytokines, such as tumor necrosis factor α and interleukin-6, which were all significantly inhibited by pretreatment with SdLv. However, herbal extracts from Bupleurum chinense DC. (Buch) or Bupleurum falcatum L. (Bufa) did not affect M. abs-induced activation of proinflammatory responses. Importantly, we demonstrated that generation of intracellular reactive oxygen species, which are important signaling intermediaries in the activation of NF-κB and the MAPK signaling pathway, was rapidly increased in Mab-infected macrophages, and this was effectively suppressed by pretreatment with SdLv, but not Buch and Bufa. We further found that the treatment of Buch and Bufa, but not SdLv, led to the activation of NF-κB and the MAPK signaling pathway and the generation of intracellular reactive oxygen species. Moreover, oral administration of SdLv significantly reduced lethality in Mab-infected mice. Collectively, these results suggest the possible use of SdLv as an effective treatment for Mab infection.

Polysaccharides extracted from the roots of Bupleurum chinense DC modulates macrophage functions

The present study aimed to investigate the effects of polysaccharides extracted from Bupleurum chinense DC (BCPs) on macrophage functions. In the in vivo experiment, 1 mL of 5% sodium thioglycollate was injected into the abdomen of the mice on Day 0 and macrophages were harvested on Day 4. The macrophages were cultured in plates and treated with different concentrations of BCPs and stimulus. Effects of BCPs on macrophage functions were assessed by chemotaxis assay, phagocytosis assay and Enzyme-Linked Immunosorbent Assay (ELISA). Our results showed the enhanced chemotaxis, phagocytosis and secretion of nitric oxide (NO) and inflammatory cytokines by macrophages when treated with BCPs. However, when chemotaxis and phagocytosis were up-regulated by complement components or opsonized particles, BCPs inhibited these effects. Also, the NO production induced by lipopolysaccharides (LPS) was suppressed by BCPs mildly. Moreover, BCPs had an inhibitory effect on the [Ca²⁺]_i elevation of macrophages. These results suggested that BCPs exerted modulatory effects on macrophage functions, which may contribute to developing novel approaches to treating inflammatory diseases.

Advances on Bioactive Polysaccharides from Medicinal Plants

In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

Anti-Complementary Components of Helicteres angustifolia

A first phenalenon derivative with an acetyl side chain at C-8, 8-acetyl-9-hydroxy-3-methoxy-7-methyl-1-phenalenon (compound 1), and a pair of new sesquilignan epimers at C-7″ of hedyotol C and hedyotol D analogs, hedyotol C 7″-O-β-d-glucopyranoside (compound 2) and hedyotol D 7″-O-β-d-glucopyranoside (compound 3) were isolated from the aerial parts of Helicteres angustifolia together with nine known compounds (4–12). Their structures were elucidated on the basis of spectroscopic methods, including mass spectroscopy, and 1D and 2D nuclear magnetic resonance. Eleven isolates exhibited anti-complementary activity. In particular, compounds 4 and 5 exhibited potent anti-complementary activities against the classical and alternative pathways with CH₅₀ values of 0.040 ± 0.009 and 0.009 ± 0.002 mM, and AP₅₀ values of 0.105 ± 0.015 and 0.021 ± 0.003 mM, respectively. The targets of compounds 4 and 5 in the complement activation cascade were also identified. In conclusion, the anti-complementary components of H. angustifolia possessed chemical diversity and consisted mostly of flavonoids and lignans in this study.

Chemical Structure and Immunomodulating Activities of an α-Glucan Purified from Lobelia chinensis Lour

A neutral α-glucan, named BP1, with a molecular mass of approximately 9.45 kDa, was isolated from Lobelia chinensis by hot-water extraction, a Q-Sepharose Fast Flow column and Superdex-75 column chromatography. Its chemical structure was characterized by monosaccharide analysis, methylation analysis and analysis of its FT-IR, high performance gel permeation chromatography (HPGPC) and 1D/2D-NMR spectra data. The backbone of BP1 consists of →₆α-d-Glcp¹→6,3α-d-Glcp¹→(₆α-d-Glcp¹)x-6,3α-d-Glcp¹-(₆α-d-Glcp¹)y→. The side chains were terminal α-d-Glcp¹→ and α-d-Glcp¹→ (₆α-d-Glcp¹)z→₄α-d-Glcp¹→₃α-d-Glcp¹→₄α-d-Glcp¹→ (x + y + z = 5), which are attached to the backbone at O-3 of 3,6α-d-Glcp¹. The results of the effect of BP1 on mouse macrophage cell line RAW 264.7 indicate that BP1 enhances the cell proliferation, phagocytosis, nitric oxide production and cytokine secretion in a dose-dependent manner. Because the inhibitor of Toll-like receptor 4 blocks the BP1-induced secretion of TNF-α and IL-6, we hypothesize that α-glucan BP1 activates TLR4, which mediates the above-mentioned immunomodulating effects.

Development of a C3c-based ELISA method for the determination of anti-complementary potency of Bupleurum polysaccharides

Traditionally, determination of inhibitory potency of complement inhibitors is performed by the hemolytic assay. However, this assay is not applicable to the lectin pathway, thus impeding the understanding of complement inhibitors against the overall function of the complement system. The main objective of our study was to develop a specific enzyme-linked immunosorbent assay (ELISA) as an alternative method to assess the anti-complement activity, particularly against the lectin pathway. By using respective coating substrates against different activation pathways, followed by capturing the stable C3c fragments, our ELISA method can be used to screen complement inhibitors against the classical pathway and the lectin pathway. The inhibitory effect of suramin on the classical pathway, as measured by our hemolytic assay is consistent with previous reports. Further assessment of suramin and Bupleurum polysaccharides against the lectin pathway showed a good reproducibility of the method. Comparison of the lectin pathway IC₅₀ between Bupleurum smithii var. parvifolium polysaccharides (1.055 mg/mL) and Bupleurum chinense polysaccharides (0.98 mg/mL) showed that, similar to the classical and alterative pathway, these two Bupleurum polysaccharides had comparable anti-complementary properties against the lectin pathway. The results demonstrate that the described ELISA assay can compensate for the shortcomings of the hemolytic assay in lectin pathway.

Purification, characterization and immunomodulating activity of a polysaccharide from flowers of Abelmoschus esculentus

A water-soluble polysaccharide (OFPS11) was obtained from okra (Abelmoschus esculentus) flowers using aqueous extraction and purification with DEAE-52 cellulose and Sephacryl™ S-500 column. Its preliminary characterization and immunomodulating activity were investigated. Results showed that OFPS11 is mainly composed of galactose and rhamnose in a molar ratio of 2.23:1 with molecular mass of 1,700 kDa. RAW264.7 cells pretreated with OFPS11 significantly inhibited the proliferation of HepG-2 cells. Additionally, OFPS11 enhanced the phagocytic ability and induced the elevation of NO production, TNF-α and IL-1β secretion of RAW264.7 cells. Furthermore, OFPS11 promoted both the expression of iNOS protein and of iNOS and TNF-α mRNA. OFPS11 can strongly increase NF-κB levels in nucleuses, which is an important transcription factor that can modulate expressions of iNOS, NO and TNF-α. These outcomes support that OFPS11 exerts its antitumor activity by probably stimulating macrophage activities through nuclear NF-κB pathway.

Homogalacturonans from preinfused green tea: structural characterization and anticomplementary activity of their sulfated derivatives

Two homogeneous water-soluble polysaccharides (TPSR4-2B and TPSR4-2C) were obtained from preinfused green tea. Their average molecular weights were estimated to be 41 kDa and 28 kDa, respectively. A combination of composition, methylation, and configuration analysis, as well as NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1-4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and 28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester. Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid-pyridine ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C demonstrated a stronger inhibitory effect on the complement activation through the classic pathway, compared to that of heparin. Preliminary mechanism studies by using complement component depleted-sera indicated that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r, C1s, C2, C5, and C9 but not with C3 and C4. The relationship between DS and the anticomplementary activity of sulfated derivatives of homogalacturonans showed that low sulfated derivatives of homogalacturonans also exhibited potent anticomplementary effect, which might greatly reduce the side effects related to heparin and oversulfated chondroitin sulfate, such as anticoagulant activity and allergic-type reaction. These results suggested that sulfated derivatives of homogalacturonans might be promising drug candidates for therapeutic complement inhibition.