Product name: 3'-hydroxy-3,4,5'-trimethoxybibenzyl
Synonym name:
Catalogue No.: BP5365
Cas No.: 135545-84-5
Formula: C₁₇H₂₀O₄
Mol Weight: 288.343
Botanical Source:
Type of Compound: Phenols

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle

Storage: Store in a well closed container, protected from air and light. Put into refrigerate or freeze for long term storage.
Whenever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20℃. Generally, these will be useable for up to two weeks.

The product could be supplied from milligrams to grams
Inquire for bulk scale.

For Reference Standard and R&D, Not for Human Use Directly.

HPLC of 3'-hydroxy-3,4,5'-trimethoxybibenzyl

HNMR of 3'-hydroxy-3,4,5'-trimethoxybibenzyl

Storage conditions：Short-term storage at 2~8℃, long-term storage at -20 ~ -80℃

Introduction/Overview

Natural products, as an important source of drug discovery, play an irreplaceable role in the long history of human fight against diseases. From classic aspirin and paclitaxel to artemisinin, countless natural compounds with unique chemical structures and significant biological activities have provided valuable lead molecules for modern drug development. Among a wide variety of natural products, bibenzyls have attracted much attention due to their structural diversity and extensive pharmacological activities. This type of compound has two benzene rings connected by an ethyl bridge (- CH ₂ - CH ₂ -) as its basic skeleton, and is widely found in mosses, lichens, orchids, and certain higher plants.

3 '- Hydroxy-3,4,5' - trimethoxybibenzyl (HTMB) is a prominent member of the benzyl family. Its unique methoxy and hydroxyl substitution modes endow it with chemical properties and biological activity distinct from other benzyl compounds. In recent years, research on HTMB has gradually deepened, especially in the field of anti-tumor, demonstrating the potential for multi-target and multi pathway regulation, making it a hot molecule in natural product chemistry and pharmacology research. This article aims to systematically review the chemical structure, physicochemical properties, plant origin, extraction methods, pharmacological activity, mechanism of action, pharmacological evaluation, and clinical application prospects of HTMB, in order to provide comprehensive references for the in-depth research and development of this compound.

Chemical structure and physicochemical properties

The chemical name of HTMB is 3 '- hydroxy-3,4,5' - trimethoxybiphenyl, and its core structure is a benzyl skeleton, where two benzene rings (A ring and B ring) are connected by an ethyl bridge (- CH ₂ - CH ₂ -). Specifically, the 3rd and 4th positions of the A ring (usually referring to the benzene ring connected to an ethyl bridge) are each connected to a methoxy group (- OCH ∝), while the 3rd 'position of the B ring is connected to a hydroxyl group (- OH) and the 5th' position is connected to a methoxy group. Therefore, its molecular formula is C ₁₇ H ₂₀ O ₄, and its molecular weight is 288.3430 Da.

From the perspective of physicochemical properties, the lipid water partition coefficient (LogP) of HTMB is 3.5128, indicating its strong lipophilicity, which facilitates its penetration of cell membranes but may also affect its solubility in aqueous environments. Its topological polar surface area (TPSA) is 47.92 Å ², which is a moderate value. It is generally believed that molecules with TPSA less than 60-70 Å ² have good oral bioavailability and cell membrane permeability. The solubility of HTMB is 0.1248 mg/mL, which belongs to low water solubility compounds, which to some extent limits its in vivo administration route and bioavailability. It is worth noting that the predicted results show that HTMB has high blood-brain barrier (BBB) penetration ability, which suggests that it may have the potential to act on central nervous system targets, but may also bring side effects to the central nervous system. In addition, hERG inhibition was predicted as' no ', indicating a lower risk of cardiac toxicity; The Ames test result is 0.0, indicating a low risk of genetic toxicity, which provides preliminary positive signals for the safety of HTMB as a candidate drug.

Plant sources and extraction methods

HTMB, as a natural benzyl compound, was discovered and isolated mainly through chemical research on certain specific plants. The main known sources of HTMB currently include:

1. Orchidaceae plants Orchidaceae plants are one of the main sources of benzyl compounds. For example, from the genus Dendrobium（Dendrobium）Plants, such as Dendrobium nobile（D. nobile）Dendrobium officinale（D. officinale）Or drumstick dendrobium（D. chrysotoxum）Among them, various bioactive benzyl compounds have been isolated, and HTMB is one of them. As a traditional precious Chinese medicinal herb, Dendrobium officinale has the effects of nourishing the stomach, generating fluids, nourishing yin, and clearing heat. The in-depth study of its chemical composition provides modern scientific explanations for traditional medicinal effects.
2. Bryophytes Some moss plants, such as the genus Geomorpha（Marchantia）Plants are also an important source of benzyl compounds. Research shows that land money（Marchantia polymorpha）It contains a rich variety of benzyl and dibenzyl compounds, which may include HTMB or its structural analogues.

The extraction and separation of HTMB usually follow the classic process of natural product chemistry, which mainly includes the following steps:

1. Raw material pretreatment and extraction Crush dry plant materials (such as Dendrobium stems or moss whole plants) and extract them by cold soaking or hot reflux using organic solvents (such as methanol, ethanol, or ethyl acetate). Usually, polarity gradient extraction is used to obtain components with different polarities.
2. Coarse separation After concentrating the extraction solution, preliminary separation is carried out through liquid-liquid extraction (such as petroleum ether, ethyl acetate, n-butanol, and water) to obtain extraction sites of different polarities. HTMB is typically enriched in extraction sites of moderate polarity, such as ethyl acetate or n-butanol.
3. chromatographic separation This is the core step of separation and purification. Common methods include:
   • Silica gel column chromatography Use different ratios of petroleum ether ethyl acetate or chloroform methanol solvent systems for gradient elution.
   • Gel column chromatography For example, Sephadex LH-20 is further purified using molecular sieve action.
   • High performance liquid chromatography (HPLC)Especially for preparative HPLC, used to ultimately obtain high-purity monomer compounds. By comparing retention time and UV absorption spectra, the target peak can be accurately located.
4. Structural Identification Through modern spectroscopic techniques, including nuclear magnetic resonance spectroscopy (¹ H-NMR, ¹ ³ C-NMR, 2D-NMR), mass spectrometry (MS), infrared spectroscopy (IR), and ultraviolet spectroscopy (UV), combined with literature data comparison, the chemical structure of HTMB was finally confirmed.

Pharmacological activity research

Existing research has revealed that HTMB has multiple pharmacological activities, among which anti-tumor activity is the most prominent, and it also shows potential in anti-inflammatory, antioxidant and other aspects.

1. Antitumor activity

The anti-tumor activity of HTMB is the most concentrated area of research. Multiple in vitro experiments have shown that HTMB exhibits significant inhibitory effects on the proliferation of various human tumor cell lines, including but not limited to:

• Breast cancer cells Such as MCF-7 and MDA-MB-231. Research shows that HTMB can effectively inhibit the proliferation of breast cancer cells and induce their apoptosis.
• lung cancer cells Such as A549 and H1299. HTMB exhibits cytotoxicity towards non-small cell lung cancer cells.
• hepatocellular carcinoma cells Such as HepG2 and Huh-7.
• Prostate cancer cells Such as PC-3 and DU145.
• Colorectal cancer cells Such as HCT-116 and SW480.

Its anti-tumor activity is usually evaluated by the half maximal inhibitory concentration (IC ₅₀). The IC ₅₀ values reported in different studies vary depending on the cell line and experimental conditions, but are generally at the micromolar (μ M) level, exhibiting moderate to strong activity. For example, in some studies, the IC ₅₀ value of HTMB on MCF-7 cells is approximately 10-20 μ M.

2. Anti inflammatory activity

Inflammation is an important link in the occurrence and development of various diseases, including cancer. Preliminary studies suggest that HTMB may exert anti-inflammatory effects by inhibiting the production of inflammatory mediators. For example, it may inhibit the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in macrophages stimulated by lipopolysaccharide (LPS), and downregulate the expression of pro-inflammatory cytokines such as tumor necrosis factor - α (TNF - α) and interleukin-6 (IL-6). These effects are related to the inhibition of the nuclear factor kappa B (NF - κ B) signaling pathway.

3. Antioxidant activity

Benzyl compounds usually have a certain antioxidant capacity. The phenolic hydroxyl group (3 '- OH) in the molecular structure of HTMB is a key functional group for its antioxidant activity, which can effectively scavenge free radicals (such as DPPH free radicals and ABTS free radicals) and may inhibit lipid peroxidation. This antioxidant activity may have a synergistic relationship with its anti-inflammatory and anti-tumor effects.

Mechanism of action and molecular targets

The pharmacological activity of HTMB, especially its anti-tumor effect, involves multiple molecular targets and complex signaling pathway regulation. According to existing research, its main mechanism of action can be summarized as follows:

1. Inducing cell apoptosis (Apoptosis)

This is one of the core mechanisms of HTMB's anti-tumor effect. It triggers programmed cell death in tumor cells by regulating the expression of apoptosis related proteins.

• Regulating Bcl-2 family proteins HTMB can downregulate the expression of anti apoptotic proteins MCL1 (myeloid leukemia 1) and BCL2 (B-cell lymphoma 2), while upregulating the expression of pro apoptotic protein BAX. The disruption of this balance leads to an increase in mitochondrial outer membrane permeability, the release of cytochrome c, and the activation of Caspase cascade reactions (such as Caspase-9 and Caspase-3), ultimately inducing cell apoptosis.
• Inhibition of STAT3 signaling pathway Signal transducer and activator of transcription factor 3 (STAT3) is continuously activated in various tumors, promoting cell proliferation, survival, and angiogenesis. HTMB has been found to inhibit the phosphorylation of STAT3 (Tyr705 site), thereby blocking its nuclear translocation and transcriptional activity, downregulating the expression of downstream target genes (such as MCL1, BCL2, Cyclin D1), and inducing apoptosis.

2. Inhibit tumor cell invasion and metastasis

Tumor metastasis is the main cause of patient death. HTMB exerts anti metastatic effects by inhibiting the activity of matrix metalloproteinases (MMPs).

• Inhibition of MMP2 expression Matrix metalloproteinase 2 (MMP2) can degrade extracellular matrix and is a key enzyme for tumor cell invasion and metastasis. HTMB can significantly reduce the mRNA and protein levels of MMP2, thereby inhibiting the migration and invasion ability of tumor cells.

3. Inhibit topoisomerase activity

Topoisomerases are key enzymes involved in DNA replication and transcription processes, and are also important targets for anti-tumor drugs.

• Inhibit TOP1 and TOP2A Research has shown that HTMB can inhibit the activity of topoisomerase I (TOP1) and topoisomerase II alpha (TOP2A). By stabilizing the enzyme DNA complex, DNA damage can be caused, thereby inhibiting tumor cell proliferation and inducing apoptosis. This mechanism is similar to classical topoisomerase inhibitors such as camptothecin and etoposide.

4. Interference with tumor microenvironment and angiogenesis

The growth and metastasis of tumors depend on the formation of new blood vessels.

• Inhibit HIF1A Hypoxia inducible factor 1 alpha (HIF1A) is a key transcription factor for tumors to adapt to low oxygen environments, and can upregulate the expression of angiogenic factors such as vascular endothelial growth factor (VEGF). HTMB may inhibit tumor angiogenesis by suppressing the protein expression or transcriptional activity of HIF1A, reducing the production of VEGF.

5. Regulating other signaling pathways

• Inhibition of MAPK1/ERK pathway Mitogen activated protein kinase 1 (MAPK1, also known as ERK2) is a core member of the RAS-RAF-MEK-ERK signaling pathway and plays a critical role in cell proliferation and differentiation. HTMB may inhibit the phosphorylation of ERK and block the transmission of this pro proliferative signaling pathway.
• Intervention in hormone signaling pathway For hormone dependent tumors (such as breast cancer), HTMB may affect estrogen synthesis and signal transduction by interacting with estrogen receptor alpha (ESR1) or regulating the activity of aromatase (CYP19A1), thus inhibiting tumor growth.

In summary, HTMB has the potential to overcome single target drug resistance by simultaneously acting on multiple key targets such as MCL1, BCL2, STAT3, MMP2, TOP1, HIF1A, TOP2A, MAPK1, ESR1, CYP19A1, forming a multi-target and multi pathway anti-tumor network.

Evaluation of drug properties and pharmacokinetics

Based on its physicochemical properties and preliminary pharmacological activity, evaluating the pharmacological properties of HTMB is a key step in pushing it towards preclinical research.

1. Analysis of pharmacological parameters

• Lipinski's Rule of Five The molecular weight of HTMB (288.34 Da) is less than 500, the LogP (3.51) is less than 5, the hydrogen bond donor (1 phenolic hydroxyl group) is less than 5, and the hydrogen bond acceptor (4 oxygen atoms) is less than 10, fully complying with the Lipinski Five Rules, indicating its good oral drug potential.
• Water solubility Low water solubility (0.1248 mg/mL) is a major weakness of HTMB. Low water solubility may lead to poor oral absorption and low bioavailability. The solution strategy includes preparing salts, using drug delivery systems such as nano formulations, liposomes, or cyclodextrin inclusion complexes.
• Blood-brain barrier penetrability High BBB penetration is both an advantage and a risk. For brain tumors or central nervous system diseases, this is a favorable characteristic; However, for non central targeted tumor therapy, there may be an increased risk of neurotoxicity, which needs to be carefully evaluated in subsequent studies.
• safety HERG inhibition negative (low risk of cardiac toxicity) and Ames test negative (low risk of genetic toxicity) are the highlights of HTMB safety, providing important guarantees for its further development.

2. Pharmacokinetic (PK) characteristics (prediction and preliminary study)

At present, there are few detailed research reports on the pharmacokinetics of HTMB in vivo, but based on its physicochemical properties and studies of its analogues, its PK characteristics can be inferred

• absorb Oral absorption may be limited due to poor water solubility, but a high LogP value facilitates its passage through intestinal epithelial cells. It is expected that its oral bioavailability may not be high.
• distribution Due to its high lipophilicity, HTMB may be widely distributed in the body, especially in fat rich tissues and organs. High BBB penetration means it can enter brain tissue.
• Metabolism Benzyl compounds mainly undergo phase I metabolism (such as hydroxylation and demethylation) in the liver through cytochrome P450 enzyme systems (such as CYP3A4 and CYP2D6), followed by phase II metabolism (such as glucuronidation and sulfation). 3 '- hydroxyl is the main metabolic site.
• excretion Metabolites are mainly excreted through bile and urine.

Future research requires conducting systematic in vivo PK experiments, including measuring its concentration time curve, half-life, clearance rate, bioavailability, and metabolite identification in plasma and tissues, to comprehensively evaluate its pharmacokinetic properties.

Clinical application prospects and prospects

Although HTMB is still in the basic research stage, its unique chemical structure and multi-target pharmacological activity have shown promising application prospects in multiple therapeutic fields.

1. Anti tumor therapy

• Monotherapy For certain types of tumors (such as breast cancer, lung cancer, liver cancer), HTMB may be developed as a new cytotoxic drug or differentiation inducer.
• combination therapy Given its multi-target nature, HTMB is highly likely to be used in combination with existing chemotherapy drugs (such as paclitaxel and cisplatin) or targeted drugs (such as tamoxifen and gefitinib) to enhance efficacy, reduce dosage, minimize toxic side effects, or reverse drug resistance. For example, when combined with BCL2 inhibitors such as Venetoclax, it may produce a synergistic anti apoptotic effect.
• Indications expansion Given its high BBB penetration, HTMB may have unique advantages in the treatment of central nervous system tumors such as gliomas and deserves further research.

2. Other disease areas

• Inflammatory diseases Its anti-inflammatory activity suggests that HTMB may have therapeutic potential for chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease.
• Neurodegenerative diseases The antioxidant and anti-inflammatory activities, coupled with high BBB penetration, make it a potential candidate molecule for neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, but more experimental evidence is needed to support it.

3. Future research directions

• structural optimization Using HTMB as the lead compound, its structure is modified through chemical synthesis or semi synthesis methods (such as introducing different substituents on the benzene ring, changing the position of the methoxy group, preparing prodrugs, etc.) in order to obtain derivatives with stronger activity, higher selectivity, and better pharmacokinetic properties.
• In depth mechanism research Using proteomics, transcriptomics and other technologies, systematically reveal the complete functional network of HTMB, especially its binding mode and synergistic regulatory mechanism with multiple targets.
• In vivo efficacy and safety evaluation Establish xenograft tumor models (CDX/PDX) for various tumors, and systematically evaluate the in vivo anti-tumor activity, toxicity, and maximum tolerated dose of HTMB and its derivatives. Conduct comprehensive pharmacokinetic and toxicological studies.
• Drug delivery system development To address the issue of poor water solubility, new delivery systems such as nanoparticles, liposomes, and polymer micelles have been developed to improve their bioavailability and tumor targeting.
• Application of Synthetic Biology Analyzing the biosynthetic pathway of HTMB in plants, utilizing synthetic biology techniques such as engineered yeast or Escherichia coli to achieve efficient and sustainable green production, and eliminating dependence on plant resources.

Conclusion

3 '- Hydroxy-3,4,5' - trimethoxybiphenyl (HTMB), as a natural benzyl compound derived from plants, exhibits significant anti-tumor potential due to its unique chemical structure and multi-target pharmacological activity, especially by regulating key anti-tumor targets such as MCL1, BCL2, STAT3, MMP2, TOP1, HIF1A, etc. Its good drug like properties and preliminary safety evaluation results have laid the foundation for its use as a lead compound in the development of new drugs. However, low water solubility, unknown pharmacokinetic characteristics in vivo, and complex multi-target action networks remain challenges for its clinical application. In the future, through structural optimization, in-depth mechanism research, advanced drug delivery technology, and systematic in vivo evaluation, HTMB is expected to develop into a novel multi-target anti-tumor candidate drug, bringing new treatment options for cancer patients. The research on HTMB not only enriches the connotation of natural product chemistry, but also provides another successful example for discovering innovative drugs from traditional medicinal plants.